using 14.047 for desired AFR and not 14.63?

[98 tigershark]

Before reading or responding please note the ? at the end. When we buy gas today it is very difficult to stay away from 10% ethanol. When setting up our tune we use an AFR as 14.63 approx for the most part and 1 for lambda and EQ. But what is the correct Base AFR to use with the fuel in the market today.
AFR is based on 14.63 part of air to 1 part of fuel. But when you do the math with 10% ethanol it seems way off to me. So I did just a little math for an open discussion and input. 10% ethanol has a correct AFR of 8.8 to 1, I think.
so since the fuel in general has 10% ethanol and the AFR for that is 8.8 approx I used the following formula. (14.63x90%) = 13.167+(8.8x10%)=14.077 or (14.63x9=131.67)+(8.8x1=8.8)=140.47/10=14.047AFR. Is 14.047 AFR or 14.077AFR the correct base to use for AFR with todays gas? If so what does this do to EQ and Lambda?. This seems correct to me so does anyone know what the adjustment should be?
Thanks in advance,
98 tigershark :throw::crash::nixweiss::blahblah:

[chevy052500hd]

open up a flex fuel cal from a truck, for 10% ethonal in the fuel that is the proper afr 14.07. Most cars are set 14.63 for regular gas obviously and then the computer will compensate for the 10% ethonal via the stft and ltft which is what I was lead to understand from the info I have been reading.

[98 tigershark]

That is my understanding also. But if the trims are trying to adjust (learn) to 14.63, it would seem that the PCM is learning to make the car run lean. Enough to make the LTFT off by quit a bit it would seem. The reason I brought this up is there is another members post on the forum who is having LTFT trims off by as much as 20%. If it is not a bad fuel filter or intake/exhaust leak it seems to me it could be the fuel he gets has changed to cause this.
Thanx,
98 tigershark

[vetteboy2k]

I believe the narrow bands will adjust to stoich of whatever the AFR is of the fuel your running. So if pure gasoline they will adjust to stoich which is 14.68 and if E10 14.07 being stoich is stoich and the sensors don't know the type of fuel your running.

[SSpdDmon]

Correct. The NBO2's will report back to the PCM that there is a lean condition and then the PCM will increase fuel trims to richen up the mixture. In essence, the car should "learn" at cruise and transfer additional fueling requirements to WOT. Those who are running in open loop will need to adjust their tune manually.

[98 tigershark]

In {B3601} can we use 14.07 and be Ok with the trims or is it the EQ that is the deal here? There is not one Gas station I am aware of in close range of were I live that sells Gas without 10% ethanol.
98 tigershark

[Lextech]

Subscribing!!!

Jeff

[vetteboy2k]

If you use Lambda in your PE table {B3618} then it will look up your {B3601} and compute the desired fueling based upon your entered value in {B3601}.

For example say you command .88 lambda for your PE table {B3618} and use 14.68 for {B3601}, your commanded fuel would be 12.91 now if you change your {B3601} to 14.07 and the same .88 lambda for {B3618} you would be commanding 12.38 instead.

Using lambda .88 keeps the fueling consistent at 12% richer than stoich for WOT depending on the fuel you run and your value in {B3601}

Greg aka "eficalibrator" could probably clarify it better than I though

[98 tigershark]

Hey SSpdDmon,

I am not trying to be difficult but I cant seem to get my brain around this.
The NBO2 sensor will detect a lean condition because there is one, that I get. but why not just use the 14.07 in the 97-04 PCMs B3601. That would mean that 14.07 is stoich for those PCms then if that is the fuel ie. 10% ethanol? Right? or wrong? Help anyone, help!:help2:
98 tigershark


Correct. The NBO2's will report back to the PCM that there is a lean condition and then the PCM will increase fuel trims to richen up the mixture. In essence, the car should "learn" at cruise and transfer additional fueling requirements to WOT. Those who are running in open loop will need to adjust their tune manually.

[5.7ute]

It would be an easy test 98 tigershark.
Compare the commanded AFR in a log with 14.63 in B3601 to a log with 14.07 in B3601.
Since the computer thinks in EQ, changing this calibration should cause a change in commanded AFR.

[98 tigershark]

5.7ute, that is ingenious. I will make a few adjustments, try it and log before and after and post the results. Anyone else want to try this and compare logs?
98 tigershark



It would be an easy test 98 tigershark.
Compare the commanded AFR in a log with 14.63 in B3601 to a log with 14.07 in B3601.
Since the computer thinks in EQ, changing this calibration should cause a change in commanded AFR.

[98 tigershark]

Before I do this it would be nice to know for sure that you guys dont already know what is going to happen. I think also that I am more than willing to do this but it would be best if we could get 3 or 4 of us as to compare for accuracy and then we could compare logs and see for sure. Are you guys sure you dont already know?
98 tigershark

[5.7ute]

I can have a look after work with the Roadrunner hooked up.(In about 9 hours) You would see an instant change in commanded AFR that way.

[98 tigershark]

hello vetteboy,

I want to make it perfectly clear that I do not know the answer to this but it would seem that we could then use E85 and the PCM would automatically adjust to stoich regardless of fuel as the sensors would show a very lean condition and then adjust the trims to a 1 EQ accordingly?
That still does not sound right. I am certainly not saying anyone is wrong as I do not know, It just sounds wrong to me with the 97-2004 PCMs.
So are you interested in trying a little experiment 5.7ute suggested?
Using 14.07 for afr and comparing logs?
Looking for help,
98 tigershark


I believe the narrow bands will adjust to stoich of whatever the AFR is of the fuel your running. So if pure gasoline they will adjust to stoich which is 14.68 and if E10 14.07 being stoich is stoich and the sensors don't know the type of fuel your running.

[98 tigershark]

Thanks 5.7ute,

That is a very nice offer if you have the time and it does not have to be today as you are probably very tired late in the day. But when you can find the time that sounds great as I think this will become more and more of an issue with fuel in the future. I would sure appreciate getting my brain around this and knowing for sure (It took me getting a serious brain disease to prove to my wife I had a brain, really). I may be wrong but I think when you put 14.07 into B3601 that becomes the EQ of 1. I guess we shall see soon enough. Thank you so much and I am still willing to try it, but I think we need a few volunteers to compare logs and notes as I am not a pro at this ind of thing.
98 tigershark



I can have a look after work with the Roadrunner hooked up.(In about 9 hours) You would see an instant change in commanded AFR that way.

[5.7ute]

I am doing some idle work on my car after work anyway. I will let you know what I find.

[98 tigershark]

That is way cool, Thank you!
98 tigershark



I am doing some idle work on my car after work anyway. I will let you know what I find.

[mr.prick]

It would be an easy test 98 tigershark.
Compare the commanded AFR in a log with 14.63 in B3601 to a log with 14.07 in B3601.
Since the computer thinks in EQ, changing this calibration should cause a change in commanded AFR.

It will and it will change the AFR values in {B3605}

[5.7ute]

It will and it will change the AFR values in {B3605}

That is a good point mr.prick. You need to close & reopen the tunetool though to have it take effect.
What this tells you is that by changing {B3601} to match the stoichemetry of the fuel you are using, your enrichment percentages will remain intact. There is no need to recalibrate any of the commanded fuel tables.(unless of course you want a different enrichment percentage for the new fuel)
It also highlights the need to set {B3601} to the stoichemetry of the fuel you are using when doing autoVE with any commanded EQ not equal to 1.0. (like in a custom OS where STFT are enabled when commanding stoich.)

Once again a new thread points out a new trap in previous methods of tuning.:fluffy:

[SSpdDmon]

That is a good point mr.prick. You need to close & reopen the tunetool though to have it take effect.
What this tells you is that by changing {B3601} to match the stoichemetry of the fuel you are using, your enrichment percentages will remain intact. There is no need to recalibrate any of the commanded fuel tables.(unless of course you want a different enrichment percentage for the new fuel)
It also highlights the need to set {B3601} to the stoichemetry of the fuel you are using when doing autoVE with any commanded EQ not equal to 1.0. (like in a custom OS where STFT are enabled when commanding stoich.)

Once again a new thread points out a new trap in previous methods of tuning.:fluffy:
I'm trying to follow along and I think I agree. Basically, there's two things going on here. One is with the software (EFI Live) and the other is with the PCM/tune. When you display AFR instead of EQ in EFI Live, the software is simply converting EQ to AFR for you on the surface based on 14.63. However, in the background - EQ is still loaded into the car when you flash the file. Unfortunately, the AFR setting can't be changed away from 14.63 in the preferences. **Maybe with a little tweak to some code it could.** But as of now, it can't. So, any table that that opperates based on EQ in your tune file will be converted to AFR when viewed in EFI Live under the assumption that you're using 100% gasoline.

What this means is...let's say you're using 10% ethanol with a true stoich of 14.08 and your display preferences in EFI Live are to show AFR. So, you set 3601 to 14.08 (this cell is not affected by the display settings). In your PE (which is still showing AFR based on gasoline), say you have it set to command an AFR of 13.0. In the background, the real number that gets loaded into the PCM is 1.13. Therefore, you should see a commanded AFR in your log of 12.46....not 13.0....since you changed 3601 to 14.08 (14.08/1.13=12.46).

To avoid confusion, you ideally want to operate with EQ and set 3601 accordingly. But even if you don't switch off of AFR in the display preferences, it shouldn't be as dramatic of an inaccuracy as some have made it out to be. You just have to remember, what shows in AFR when looking at the tune file through the software is based on gasoline....not what you have in 3601. As long as you remember that, the PCM *should* adjust accordingly assuming you are using the right B3601 and you're looking to use the same enrichment ratio (EQ of 1.13 in my example) for the fuel you're using.

Sorry if I lost anyone - probably could explain it a little clearer. But, I'm exhausted right now... LOL

[5.7ute]

You lost me Jeff. Best you get some rest & post it again lol.:angel_innocent:
By changing B3601 you do in effect change all the commanded fuel tables when the tunetool is reopened. Are you saying it will not change in the PCM due to the preferences being locked?
While it may not be a dramatic inaccuracy, it will explain how returning to closed loop may lead to positive or negative fuel trims, or inaccuracies when the commanded AFR is changed.

[gmh308]

We do this regularly on E38's. From E0 to E85 and in between.

The LTFT's get the picture within a couple miles of a change in fuel from a gas station, and may raise a lean/rich DTC, but then once the stoich is reflashed by the approx % that the LTFT has moved (if the STFT's have settled back somewhere around zero) or the new calculated stoich based on estimate of what is in the tank, then the trims are mostly back in the right space again.

Its not quite a flex fuel setup.......:)

[eficalibrator]

To avoid confusion, you ideally want to operate with EQ and set 3601 accordingly.
YES! Ideally, you just set your defined stoich point in the table to whatever the chemistry of your fuel really is and leave it alone. (I use 14.13 for e10, 14.64 for "normal" gasoline, and 14.4 to split the difference if we're unsure of what's in the tank)

Once you've defined the stoich point, you work entirely in units of lambda or EQR for relative richness. A value of 1.0 should command whatever your predefined stoich point is for delivered AFR on the scanner. If this really matches your fuel in the tank and you've nailed both the injector tables (ALL of them) along with the airflow models, your fuel trims will be very close to zero and everything works as intended.

I can confirm that adjusting the stoich point scalar/table will indeed change the open loop fuel delivery as well as the displayed "commanded AFR" on the scanner.

When using ethanol blends (including e10), you have to break the habit of saying "I want 12.6:1 at WOT" and start thinking "I want lambda 0.86 (or 1.16 EQR) at WOT." It's the same RELATIVE enrichment, from a different stoich point; and that's all the combustion in the cylinder cares about.

Likewise, you also need to log LAMBDA or EQR from the wideband, NOT AFR. If you calculate fueling errors based on displayed AFR on the wideband divided by some modified stoich, you're asking for trouble. Further, most widebands display "AFR" by merely multiplying actual lambda by 14.64ish, which means that a displayed "14.64" on that wideband would REALLY be 14.13 for e10, since that's lambda=1.00 at the sensor. See where these start to compound? Using the "BEN factor" based on AFR just takes you a step further toward confusion in this case. That's why I log exclusively in lambda, and view GM cal tables in EQR to stay consistent even when stoich for the fuel is different.

[mr.prick]

After you save the tune values will change slightly.
Example:
14.4AFR becomes 14.42AFR.

Don't forget to change the fuel settings in your WBO2 controller to match
your new EQ1/Lambda1 and any cal_pid formulas you have relating to EQ/Lambda.

[SSpdDmon]

You lost me Jeff. Best you get some rest & post it again lol.:angel_innocent:
By changing B3601 you do in effect change all the commanded fuel tables when the tunetool is reopened. Are you saying it will not change in the PCM due to the preferences being locked?
While it may not be a dramatic inaccuracy, it will explain how returning to closed loop may lead to positive or negative fuel trims, or inaccuracies when the commanded AFR is changed.
I'm saying B3601 is what it is....always AFR because that's how the PCM reads that cell. All other fueling tables IIRC are based on EQ as a default in the GM PCM (PE, OLFA, etc.). When you alter the EFI Live preferences to show AFR, it can only be done with a stoich of 14.63 because EFI Live has that variable fixed at that ratio. So, all of those other fueling tables (PE, OLFA, etc.) will be based on gasoline's stoich on your computer screen. But when they're flashed into the PCM, they should still be loaded in the default units (EQ).

What this means is if you change B3601, the PCM should still proportionately enrich the fuel mixture in open loop (PE, OLFA, etc.) based on how it would have been done using gasoline.

So, to sum up...

1) The GM PCM sees B3601 as AFR. You'll always see B3601 as AFR because that's what GM set it to be in the PCM. Therefore, you can adjust this for the stoich of the fuel you're using regardless of the display preferences in EFI Live.
2) You can change all of the tables that defualt as EQ in the PCM (PE, OLFA, etc.) to show AFR in EFI Live. But, they'll always show AFR based on gasoline's stoich in EFI Live.
3) When flashing the PCM, the PCM should still receive the default units (EQ) regardless of your EFI Live display preferences. This is where I started to bable about how a 13.0:1 AFR (which is really a 1.13 EQ for gasoline in the background) in your PE table will translate to a 12.46:1 AFR commanded if you were to adjust B3601 to 14.08 for a 10% ethanol blend.

#3 is no different really than when you view VE as a percentage instead of the default units (g*K/kPa). When you flash the tune back into the PCM, it's getting the default unit in the background....not the VE % of theoretical maximum numbers that you see on your screen.

[joecar]

I believe Greg and Jeff are saying that we should all use EQ units since the PCM works in EQ units.

I use (and have been using) EQ units... I prefer EQ over AFR.

My serial BEN's are defined as:

BEN_SER1 = {GM.EQIVRATIO} * {EXT.WO2LAM1}
BEN_SER2 = {GM.EQIVRATIO} * {EXT.WO2LAM2}

(since the pids EXT.WO2EQ1 and EXT.WO2EQ2 don't exist)

[SSpdDmon]

I believe Greg & Jeff are saying that we should all use EQ units since the PCM works in EQ units.

I use (and have been using) EQ units... I prefer EQ over AFR.

My serial BEN's are defined as:

BEN_SER1 = {GM.EQIVRATIO} * {EXT.WO2LAM1}
BEN_SER2 = {GM.EQIVRATIO} * {EXT.WO2LAM2}

(since the pids EXT.WO2EQ1 and EXT.WO2EQ2 don't exist)
Fixed. :)

[joecar]

Ah yes, that is what I meant.

[mr.prick]

Couldn't you use {B3601}/{EXT.WO2AFR1} = External Wideband EQ

What if the WBO2 setting for Lambda1 (14.7AFR) does not match EQ1 {B3601} exactly?

[98 tigershark]

When we are setting up our WBO2 sensors Like an "whatever brand" and
it has you use 7.35 for half or .5 EQ or Lambda (look at the PID definitions and formulas in the scan,pid selection)). If the PCM kind of does the flex fuel thing as GM308 says (that seemed logical and also matches the flex fuel tables too in the later PCMs) Does that mean we cannot really use the given of 7.35 for AFR for one half of the WBO2 equation and then add what ever the WBO2 sensor says for the other half which is the actual reading? If so that suddenly does become a factor to take care of I think? I am not sure I said that right but it would seem we would have to use EQ or Lambda as Greg and Jeff say but! how does this affect the WBO2 configuration, how the 97-04 PCMs think and EFILive WBO2 PID?
98 tigershark



Couldn't you use {B3601}/{EXT.WO2AFR1} = External Wideband EQ

What if the WBO2 setting for Lambda1 (14.7AFR) does not match EQ1 {B3601} exactly?

[SSpdDmon]

After you save the tune values will change slightly.
Example:
14.4AFR becomes 14.42AFR.

Don't forget to change the fuel settings in your WBO2 controller to match
your new EQ1/Lambda1 and any cal_pid formulas you have relating to EQ/Lambda.
Correct. Stoich is always 1.0 for lambda/EQ no matter what the fuel (gasoline, E10, E85, etc.). AFR is what changes and why the WB controller needs reprogrammed.

What get's tricky is logging EQ...

It's not a linear output like the AFR voltage equations are. Further below in this thread, I explain further. With a little work in Excel, the equation can be discovered. With that in mind, it's also important to keep in mind what you really put in your tank so you can set B3601 accurately...

http://www.e85mustangs.com/regions123.html

Because they mix it up at the pumps. :)

[98 tigershark]

That is what I was wondering. So you can not assume that the given 7.35 half of the WBO2 AFR is correct when using a fuel that has 10% ethanol as stioch and is the fuel we have mostly everywhere I live. So half of 10% ethanol (14.07 stioch) is the given (7.035 instead of 7.35) plus the reading from the sensor? I guess you cant do that in all reality, so you actually really do have to use EQ or lambda when tuning and logging? I an still not sure I am saying this right but the answers are sure helping me get my brain around this.
98 tigershark

[mr.prick]

I can't match Lambda1 to EQ1 exactly between the WBO2 settings and {B3601}.

Off topic
I just looked at an old log and found
GM.AFR differed ever so slightly than what is set in the tune.
Example:
----------{B3601} = 14.628573 AFR
Actual commanded = 14.627930 AFR
Difference-------- = 00.000643
When PE kicked in GM.AFR was slightly lean too.
Is there a multiplier somewhere?

[98 tigershark]

I think GM uses the 7.35 for half of the PID calculation or close to it as an adjustment and has something to do with the EQ to Lambda thing, I dont really know but it seems that way. (you know the 7.36 or .5/ ADV1 or 2 thing were it says that bank one is 2.20 or approx before you change it to the WBO2). I still dont think I said that right. Anyway awhile back I read that the PCM simulates one of the banks and one is the actual as to Bank 1 sensor 1, bank 2 sensor 1. I will try to find the GM or EFILive article I read.
98 tigershark



I can't match Lambda1 to EQ1 exactly between the WBO2 settings and {B3601}.

Off topic
I just looked at an old log and found
GM.AFR differed ever so slightly than what is set in the tune.
Example:
----------{B3601} = 14.628573 AFR
Actual commanded = 14.627930 AFR
Difference-------- = 00.000643
When PE kicked in GM.AFR was slightly lean too.
Is there a multiplier somewhere?

[5.7ute]

Just to clarify {B3601} Our pulsewidth calculation by the PCM would be this.
IBPW=( Airmass/({B3601}/commanded EQ)/IFR) + offsets
Correct?????
Going by this an error in B3601 would still cause an error in our airflow model if we are commanding away from stoich like in a custom OS.

[98 tigershark]

I thought the PCM knows to or uses (BSFC) the brake specific fuel consumptions change to adjust for nat asp or forced induction for the COS's and also the uses VE% too. Maybe just for WOT?
98 tigerhark

Just to clarify {B3601} Our pulsewidth calculation by the PCM would be this.
IBPW=( Airmass/({B3601}/commanded EQ)/IFR) + offsets
Correct?????
Going by this an error in B3601 would still cause an error in our airflow model if we are commanding away from stoich like in a custom OS.

[mr.prick]

Just to clarify {B3601} Our pulsewidth calculation by the PCM would be this.
IBPW=( Airmass/({B3601}/commanded EQ)/IFR) + offsets
Correct?????
Going by this an error in B3601 would still cause an error in our airflow model if we are commanding away from stoich like in a custom OS.

Are you saying IBPW will change commanded AFR?
Shouldn't commanded be static, other than after start, ECT,IAT multipliers?

[5.7ute]

Are you saying IBPW will change commanded AFR?
Shouldn't commanded be static, other than after start, ECT,IAT multipliers?

No, what I am saying is an error in B3601 will bring errors into AutoVE if commanding away from stoich.
An easy example would be like this.
lets say cylinder airmass is 0.62 G/cyl. commanded afr is 1.14 EQ and the IFR is 5.0 G/sec. Offsets we will leave at 0 for simplicity
B3601 set to 14.63

IBPW = 0.62/(14.63/1.14)/5.0
IBPW = 0.0096623 sec

B3601 set to 14.04

IBPW = 0.62/(14.04/1.14)/5.0
IBPW = 0.0100683 sec
A difference of 0.000406 sec or near 1/2 m/sec in commanded pulsewidth.
I havent fully worked this out yet & could be chasing shadows or just plain overcomplicating things. Time to fire up excel & do a little math.:doh2:

[98 tigershark]

Thanks for doing the math 5.7ute. You should look at SSpdDmon link regarding E85. its pretty scary and means were I live we get the crap fuel year round. That really sucks!! But since we get the crap fuel all the time I guess it at least will be consistent for tuning so thats a positive. By the way since the AFR is set for 10% ethanol it would take a bigger pulse width as the fuel milage does also go down, Right! as it seems your math is right to me and it should be a longer IBPW.
Thanks again as I think this will be very important to learn as I sure am.
98 tigershark

[eficalibrator]

Guys, I just don't understand the resistance to using either lambda or EQR. I know you've been conditioned to see gasoline AFRs all along, but it's time to move on. You're only causing yourselves more unnecessary headaches.

[SSpdDmon]

No, what I am saying is an error in B3601 will bring errors into AutoVE if commanding away from stoich.
An easy example would be like this.
lets say cylinder airmass is 0.62 G/cyl. commanded afr is 1.14 EQ and the IFR is 5.0 G/sec. Offsets we will leave at 0 for simplicity
B3601 set to 14.63

IBPW = 0.62/(14.63/1.14)/5.0
IBPW = 0.0096623 sec

B3601 set to 14.04

IBPW = 0.62/(14.04/1.14)/5.0
IBPW = 0.0100683 sec
A difference of 0.000406 sec or near 1/2 m/sec in commanded pulsewidth.
I havent fully worked this out yet & could be chasing shadows or just plain overcomplicating things. Time to fire up excel & do a little math.:doh2:
Yes, a drop in B3601 will increase injector pulse width because you're telling the PCM the stoich AFR of the fuel you're using is richer. So, it almost goes without saying that the injectors will need to stay open longer. That's why it's important to understand what you're putting in your tank.

For me, I thought I was doing a great thing going to Sunoco and getting 94 octane gas...until I noticed it has a higher octane rating partly because it's 10% ethanol. http://www.motownmuscle.com/forums/images/smilies/swear.gif

[98 tigershark]

Hello Greg,

Thanks for the input as it is nice to have you in on this thread. I dont think there is the resistance to EQ that you think. I personally need to understand the fuel. In EFILive you do have to put in an AFR in B3601 and some of the tuners (me) use by default the 14.63 or 14.7. There have been many excelent posts put up such as 5.7ute, SSpdDmon, mr.prick and yours. This is an exelent teaching/learning issue and I for one am the student. Fuels are changing as we all know and I am really looking forward to the help in translating my tune to EQ not because of I like AFR better but it was easy and worked. Now that the fuel I can get locally for my car has changed for ever, I wanted to learn what this meant and how to adapt my EFIlive tune to EQ but mostly for the ever changing fuel and in this case 10% ethanol and maybe even E85. Did you see the http://www.e85mustangs.com/regions123.html posted by SSpdDmon. That was a real eye opener. I do think this is more about learning for me it sure is. The IBPW issue is a good example. It would be nice to have someone like yourself explain the Big changes one must employ to use E85 and to expect much worse milage and how to pass all the EPA issues with these fuels.
Thanking you in advance as this has really taught me allot and I appreciate all the input very very much. Please keep in mind that we EFILive users do have to put in an AFR value in B3601 so I need to learn what that means all the way around with fuel and the tune.
Thanks for all the input from the guys on this thread or post and I am really looking forward to learning more.
Thanks all,
98 tigershark


Guys, I just don't understand the resistance to using either lambda or EQR. I know you've been conditioned to see gasoline AFRs all along, but it's time to move on. You're only causing yourselves more unnecessary headaches.

[98 tigershark]

I had injectors that were borderline for my motor. Now that I can pretty much only get 80-90% gas with 10-20% ethanol it in all likely hood that has put my injector duty cycles past the safe percent 80% and I do go to 90% when racing a few times a year. It takes more fuel and IBPW's with ethanol in the mix to hit the targeted air to fuel ratio whether tuning with AFR,EQ or LAMBDA.
In the case of E85 I have heard it cuts the gas milage in almost half. I have heard the AFR for E85 is 8.8 to 1. That is almost double the duty cycle for the injectors to hit the desired ratios. Is this correct????
98 tigershark

[98 tigershark]

I thought I would call GMPP to find out what they do. This is what I was told;
E10=13.81 AFR
E20+11.21 AFR

I took notes all they way down the line and cannot read my writing for the rest, Sorry! Also for their flex fuel vehicles they use a Composition sensor to determine the amount of alcohol in the fuel. And the computer does the rest. SSpdDmon was right when he said we might as well have a PID for the various types of ethanol fuel for the WBO2 sensors (ie his post)
It is important to make the correct adjustments. Another point was that one needs to be careful as to the fuel that you might mix (not knowingly or intentional), in other words from Gas to E*.* and Gas, as some Gas does not have the correct ingredients to mix them. So if I went to get gas in Portland and I have a 1/4 tank of E10 i need to be careful. I dont really know what I can do about that but the difference between E10 (13.81 AFR) and regular gas (14.7 AFR) is more than a little. So you still do need to know the AFR in order to get the right EQ and or LAMBDA. Once you know the correct AFR of the fuel in your tank, you can then tune with what ever you prefer. I wonder if there is a simple sensor we could buy to check the % of ethanol that we put in our tanks?
98 tigershark

[gmh308]

I thought I would call GMPP to find out what they do. This is what I was told;
E10=13.81 AFR
E20+11.21 AFR

I took notes all they way down the line and cannot read my writing for the rest, Sorry! Also for their flex fuel vehicles they use a Composition sensor to determine the amount of alcohol in the fuel. And the computer does the rest. SSpdDmon was right when he said we might as well have a PID for the various types of ethanol fuel for the WBO2 sensors (ie his post)
It is important to make the correct adjustments. Another point was that one needs to be careful as to the fuel that you might mix (not knowingly or intentional), in other words from Gas to E*.* and Gas, as some Gas does not have the correct ingredients to mix them. So if I went to get gas in Portland and I have a 1/4 tank of E10 i need to be careful. I dont really know what I can do about that but the difference between E10 (13.81 AFR) and regular gas (14.7 AFR) is more than a little. So you still do need to know the AFR in order to get the right EQ and or LAMBDA. Once you know the correct AFR of the fuel in your tank, you can then tune with what ever you prefer. I wonder if there is a simple sensor we could buy to check the % of ethanol that we put in our tanks?
98 tigershark

Thats interesting Tigershark. They go a little over the expected numbers.

We run 9.8 here for E85, and depending on the calculated (pen and paper LOL) E mix, adjust stoich AFR in the ECM accordingly.

The GM Ethanol sensor is around 400 bucks. It generates a frequency based output based on the conductivity of the fuel.

Ethanol apparently being "1 million times"* more conductive than gasoline there is a considerable variation.

GM also uses a virtual fuel sensing setup which simply and smartly figures out the approximate mix via the O2 sensors and some software wizardry, though there have been reports that this is not reliable all the time.

We actually do have an ethanol sensor in our cars already. The PCM coupled with the O2 sensors can be used to "indicate" ethanol content and work out required AFR.

How? You log your LTFT's on your tank of gas. You know where they are then. Say they are within +/- 3. You fill up with whatever. All of a sudden your LTFT's move by 8 points up or down. Or if you go from an empty tank of straight gas to a full tank of E85 for example, the LTFT's will go to 25% reasonably soon. 25% because they generally top out in a stock tune at 1.25 rich. So you change the limit to 50% and they will probably settle at around 40-45.

Then calculate your stoich AFR from there and reflash the PCM. Might take a few shots as you home in on getting LTFT's back toward zero again. Last tank of E10 here pushed the LTFT's to around 10 points rich.

Will this work with every OS/tune? Dont know. But it works ok here on E38/E67's.

There are risks of course. Check it out incrementally.

* Source: Chrysler engineer.

[5.7ute]

Guys, I just don't understand the resistance to using either lambda or EQR. I know you've been conditioned to see gasoline AFRs all along, but it's time to move on. You're only causing yourselves more unnecessary headaches.

Greg, it is not a resistance to using EQ or lambda. It is a question of accuracy.
For instance, when tuning the VE table using a custom operating system, we must command away from an EQ ratio of 1.0 to prevent STFT from occuring. If B3601 is incorrect for the fuel being used our airmass calculation will have errors. While it may be splitting hairs it is no different from having incorrect injector data in your tune.
After all, isnt tuning about having the tables accurately reflecting the hardware & conditions.

[98 tigershark]

Thanks 5.7ute,
That is the real issue. You simply can not use EQ or Lambda for B3601 with EFILive (I do not know about HP or LS1 edit as I havent had that ever since I bought EFILive). It can inly be entered in AFR and it needs to be accurate. I am glad that Greg has gotten involved in this topic and am looking forward to his input. But with EFILive you do have to input an AFR in B3601 only as you cant use EQ or Lambda. The program wont let you. Have you looked at the program?
I do use EQ also but, need to learn what is the stoich for the EQ of 1 with the fuel and also the AFR for the program (B3601)
Also thanks GM308 that is very interesting. I have a case # with GMPP and they are great guys and always helpful. I too was a little surprised at the AFR for E10 as I thought we had the correct formula. The conductivity is also a very interesting point. Thanks GM308.
98 tigershark
PS 5.7, I had to chuckle about the race fuel (110 oct) as I did the same thing.


Greg, it is not a resistance to using EQ or lambda. It is a question of accuracy.
For instance, when tuning the VE table using a custom operating system, we must command away from an EQ ratio of 1.0 to prevent STFT from occuring. If B3601 is incorrect for the fuel being used our airmass calculation will have errors. While it may be splitting hairs it is no different from having incorrect injector data in your tune.
After all, isnt tuning about having the tables accurately reflecting the hardware & conditions.

[gmh308]

Also for open loop operation with the default OL tables, the PCM/ECM must be told what fuel it is running by setting the AFR at stoich. In closed loop it can figure this out by itself.

We work only off a lambda base at all other times. It makes life so much easier.

[5.7ute]

98 tigershark. B3601 has to be calibrated in AFR as the PCM needs to know how much fuel to inject.
Going off the last equation where
cylinder airmass is is 0.62 G/cyl
commanded EQ is 1.14
{B3601 is 14.63 &
IFR is 5.0 G/sec
What happens first is the PCM calculates the amount of air in the cylinder. In this case 0.62 grams. It will look up {B3601} which it will then divide by the commanded EQ ratio. 14.63/1.14 = 12.83333. Cylinder airmass is divided by this number to calculate how much fuel needs to be injected in grams.
0.62/12.83333 = 0.0483116 grams of fuel
The sum of these values is then divided by the IFR 5.0 g/sec to give the pulsewidth necessary to inject that amount of fuel.
0.0483116/5.0 = 0.00966233 seconds or 9.66233ms.
Hope this clears things up.

[98 tigershark]

For the record, I like all the methods of tuning EQ, LAmbda and using AFR only when I have too But I appreciate the help with this as it has really shed light on the fuel issues today and has taught me to be more aware of what I put in my tank and the accuracy issues. I am still a little unclear on how to set up the WBO2 sensor PID and programming it though with the E fuels.
98 tigershark

[eficalibrator]

Perhaps I was unclear. Yes, I do indeed populate the stoich point scalar/table. ("B3601" as you guys are calling it, I'm still used to generic table names instead of the EFILive specific alpha-numerics. GM has a COMPLETELY different naming structure in the source code)

The one and only time I use actual AFR numbers is at the very beginning of the calibration process. I ask the owner "What fuel is in the tank?" and use his answer to start with a reasonable value for B3601 (see, I'm catching on to your naming system). If he says "I use Sunoco 94 all the time" I know that it's e10 and use a value of 14.13 for B3601. From there on out, it's lambda and EQR for datalogging and table values in the open loop/PE fuel demands.

As an added bonus for the DVD buyers, I included a text file with the stoich points for a bunch of common race fuels as well. The process for tuning C16 is not any different than e10, it just centers around a different stoich point (B3601).

[CalEditor]

I have a cart to shed some light on E to Gas Ratio.

I need to get back to it and finish up some additional pages

6111

[mr.prick]

Nice spreadsheet.
I'd like to know how I can find out exactly what is in my tank without adding
another sensor.

[98 tigershark]

Thanks for looking into that and giving us the value that you use for E10.
The Gas issue mr.prick brought up is one I have been trying to get a grip on for a few months now. I was at one gas station and the truck filling the tanks next door came over to the station were we were at and said he was putting the same gas in the premium tank as he put in the tanks across the street. I hope the tanks across the street was premium also, but they were different brand stations but the same gas. How do we know? Sometimes I watch the low octane spark tables when logging to see what table I am on and that sometimes lets me know I dont have the best gas.
Appreciated,
98 tigershark


Perhaps I was unclear. Yes, I do indeed populate the stoich point scalar/table. ("B3601" as you guys are calling it, I'm still used to generic table names instead of the EFILive specific alpha-numerics. GM has a COMPLETELY different naming structure in the source code)

The one and only time I use actual AFR numbers is at the very beginning of the calibration process. I ask the owner "What fuel is in the tank?" and use his answer to start with a reasonable value for B3601 (see, I'm catching on to your naming system). If he says "I use Sunoco 94 all the time" I know that it's e10 and use a value of 14.13 for B3601. From there on out, it's lambda and EQR for datalogging and table values in the open loop/PE fuel demands.

As an added bonus for the DVD buyers, I included a text file with the stoich points for a bunch of common race fuels as well. The process for tuning C16 is not any different than e10, it just centers around a different stoich point (B3601).

[98 tigershark]

In reading the spread sheet it made me wonder what E85 would do to the fuel supply system )i.e. The fuel pump and injectors. It would seem that you almost need twice the volume of E85 as compare to Gasoline. Does this mean that if you have a modified 346 and switch to E85 that the stock fuel pump and Injector duty cycles most likely will not be able to support the built motor let alone the stock one. If this is correct what fuel pump and injectors would support a 625 hp LS3? In my case I think that even E10 gives me a problem?
Thank in advance,
98 tigershark

[hquick]

I have a cart to shed some light on E to Gas Ratio.

I need to get back to it and finish up some additional pages

6111

Interesting reading all round guys.

Thanks for the spreadsheet AJ

[mr.prick]

Looks like I maybe safe.

Conventional gasoline is used everywhere in Arizona except Metropolitan Tucson during the winter (October through March) and in Maricopa County (year-round).
Arizona Motor Fuel Supply & Distribution (http://www.azcommerce.com/doclib/ENERGY/AZ_Motor_Fuel_and_Supply_Distribution.pdf)

[CalEditor]

Nice spreadsheet.
I'd like to know how I can find out exactly what is in my tank without adding
another sensor.

You could figure out off of the O2 sensors, but I am under the impression that is a ton of work. I think Mopars do it that way.

This does not come with a Sensor
http://www.zeitronix.com/images/ECAx120.gif
Ethanol Content Analyzer (http://www.zeitronix.com/Products/ECA/ECA.htm)

Kost Moore Tools has a Fuel Composition Tester (J 44175) I use this tool to check fuel samples.
http://cgi.ebay.com/ebaymotors/GM-Kent-Moore-J-44175-Fuel-Composition-Alcohol-tester_W0QQitemZ370249443205QQcmdZViewItemQQimsxZ2 0090824?IMSfp=TL0908241610003r9255

[CalEditor]

It appears that (E) is going to be pushed with the new admin. Minnesota may have tried to pass an E20 bill for conventional cars. Other states are looking at E30 to E50.



Issues lets say up to E10.

The fuel attacks some Rubber. (get the old carb car off the road and the current admin is happy)
The fuel can attack some Metals. Some metals are damaged by the H2O that is carried in the fuel. Water buildup in he bottom of the tank.
The fuel can attack some Plastics. Carb parts, fuel tanks, fuel lines.
Vapors.


What would E10 be put into?

Lawn and garden equipment - Chain saws, Mowers, Weed whackers, 2 stroke and 4 stroke
Recreational Vehicles - ATVs, Snowmobiles, Personal water crafts, Boats, Off road vehicles, golf carts
Transportation Vehicles - Motorcycles, Mopeds, Cars, trucks, Motorized rickshaws
Construction and Farm Equipment - Generators, Power Saws, Tractors, augers
Anything that runs on gas


The Vapor thing.

The guy is out on his Snowmobile on a 10° day. All is good
The landscaper is out whacking weeds in a 110° Hot & Humid day. Breathing in the Volatile E10. After a day at work he doesn't feel so well
Increase to E30 and the guy get and OWI driving home
For the most part everything but cars and some truck don't use EVAP system.
The government has been pushing to contain the vapors that are escaping from your lawn mower and petro burning devices.
Now they will cost more. Added emissions devices.


PCM Recalibrations

Ignition System - Different Spark Curve (3D of course)
Fuel System - Different injectors and different fuel strategy
Intake System - They will need to be larger and smoother for increased flow and deposits
EVAP Systems - The stored vapors will be greater and that will have an effect on the fuel strategy.
Engine - Higher Compression, Cam Profile, New materials for the valve and Valve seats.

[98 tigershark]

Helloo mr.prick,

You are lucky. By the way the Cardinals got ripped by the refs and should be the champs. Deny Green was very smart to pick up Kurt Warner ( a truly great QB and maybe the greatest story in the history of the NFL) as quoted by Deny Green. They played in Seattle in Seattle and beat the Seahawks and the Rams bus was in a very odd place and Kurt came out and signed every kids autograph (around 1,000) and made a special point to give me and my kids one, he noticed I was pretty ill at the time and came all the way over to us and gave us all his autograph and talked with my Kids. Marshall Faulk and all the other Hotshots would not even sign one autograph for a single kid and went straight to the Buss. I am a very big Cardinal fan.
Even the Seahawks old coach said the refs were worse in favor of the Steelers than all the weird calls made against them. I like the Steelers, really, as that is what they have done twice, steel the Super bowl. At least they live up to their name and are proud of that. Oh I forgot that I am willing to trade one of the hats for your RR pcm?
Signed,
98 tigershark, a Kurt Warner and Cardinal Fan



Looks like I maybe safe.

Arizona Motor Fuel Supply & Distribution (http://www.azcommerce.com/doclib/ENERGY/AZ_Motor_Fuel_and_Supply_Distribution.pdf)

[CalEditor]

I was working with Greg and a protege of his on a Ford. We got into the discussion of fuel and E content. I started doing some research and found some basic formulas. Then I put them into action on my daily driver. WOW! It was like night and day. Next I started adjusting for it on some other car. Same results.

I still need to figure out a Max Power formula for E content. It looks to be a curve, but I keep missing it. Maybe some of the known figures are wrong. :sly:

also if Stoich is 9.0078 or 1.000 Lambda for E100 the WOT EQ ratio need to be 1.27 or .792 lambda.

E0 Stoich is 14.68 or 1.000 lambda and WOT 12.7 and a EQ ratio of 1.15639 or .86476 Lambda

I currently have been checking the fuel content and have found it to be 10% in my area. I switched the Target AFR to 14.4 just as a test and the target WOT EQ ratio to 1.17 and the car runs great. I am still doing some testing.

BTW thanks again Greg

[98 tigershark]

I agree!! I think the flash point is hotter with ethanol than with gasoline and might show the mixture to be richer than it really is. That is just a guess but the PIDs GM.HO2S11 and 21 go higher in my car with E10. In my car with gasoline they usually maxed out around .96-.98V, but with the E10 they went as High as 1.011V with the same EQ. Again I do not really know but you are on to something there, I think.
98 tigershark`

[CalEditor]

I will add the max projected HP relevant to E content. Basically how much gain in theory you could get.

[98 tigershark]

In this post we or I have learned that the ethanol fuels require more fuel to reach stoich. With that said how many of us are running over 500 hp not to mention torque and the formula for IBPWs for peak torque, allot of us I bet. With so much more fuel being needed with the addition of E10+ I have been looking into fuel pumps for EFI. They all talk about HP and LPH but when you throw ethanol into the mix you have to consider is this fuel pump going to do the job. Certainly not the stock one. I went to an old buick forum 2002 site and read the comments on their turboed fueling issues and 11, 10, and 9 sec cars. It would seem that we also need a way to convert the performance expectations of our fuel pumps to a realistic view the we have to account for Ethanol.
The blend of Sunoco racing fuel that was mentioned earlier in this post had allot of ethanol in it. Economy is another but similar issue also. How can we know for sure that our fuel pumps can handle our current configurations and still leave room for dreaming about going faster. Does anyone have a way to calculate the HP rating/flow rating for a fuel pump with the various ethanol blends?
98 tigershark

[CalEditor]

take a look at this

http://www.epi-eng.com/piston_engine_technology/thermal_efficiency.htm

A former employer (AC Nutter) had a link to it that I found a year ago. Interesting site.

[gmh308]

You could figure out off of the O2 sensors, but I am under the impression that is a ton of work. I think Mopars do it that way.

This does not come with a Sensor
http://www.zeitronix.com/images/ECAx120.gif
Ethanol Content Analyzer (http://www.zeitronix.com/Products/ECA/ECA.htm)

Kost Moore Tools has a Fuel Composition Tester (J 44175) I use this tool to check fuel samples.
http://cgi.ebay.com/ebaymotors/GM-Kent-Moore-J-44175-Fuel-Composition-Alcohol-tester_W0QQitemZ370249443205QQcmdZViewItemQQimsxZ2 0090824?IMSfp=TL0908241610003r9255

Yes it requires the standard GM $400 sensor. :( But great idea.


It appears that (E) is going to be pushed with the new admin. Minnesota may have tried to pass an E20 bill for conventional cars. Other states are looking at E30 to E50.



The landscaper is out whacking weeds in a 110° Hot & Humid day. Breathing in the Volatile E10. After a day at work he doesn't feel so well

[COLOR="Red"]Increase to E30 and the guy get and OWI driving home

EVAP Systems - The stored vapors will be greater and that will have an effect on the fuel strategy.



Cal Editor - what's with these items? Knowing that the air in Brazil is claimed to be cleaner because of the high E contents they run there and have been for years, your points on the breathing E combustion byproducts in is a good question as E has its own pungent odour even at E10 levels. E85 even worse. Cold start it is really strong on E85.

Catylised gasoline exhaust is mainly CO2 and water, so what is the bonus extra by-product with E I wonder.

But...the evaporative output from E is much lower than with gasoline as the vapour pressure is higher and its natural "fume" level is much lower.



I'd like to know how I can find out exactly what is in my tank without adding
another sensor.

Your ECM can tell you if you have access to a known non E fuel that you can approximately baseline off.

[98 tigershark]

I use .50 for my nat asp when calculating IBPWs for peak torque and since the AFR also used in the calc. would incorporate the correct the correct afr for the fuel used the E% should not matter for the BSFC . that is what I found in a few publications. So does Ethanol change the BSFC too? I may have found a sensor but I need to double check it later, my daughter just got here to visit.
98 tigershark

[mr.prick]

In a 2002 GMC Yukon tune (12216125) {B3601} is a table for % of ethanol instead
of a single value parameter.
Maybe a conversion for GEN3,
provided you can find out any sensor part numbers and what pinouts to add.

[gmh308]

In a 2002 GMC Yukon tune (12216125) {B3601} is a table for % of ethanol instead
of a single value parameter.
Maybe a conversion for GEN3,
provided you can find out any sensor part numbers and what pinouts to add.

http://www.zeitronix.com/Products/ECA/ECA.htm

If there is a table in the OS for stoich values, and you want to change it, simply change the first value - the 0% value. And optionally the second value. Why ? Have seen GM OS's (the ones with the tables) show the ethanol content as 3%, so setting the second value (6.25% ?) to your chosen stoichiometric AFR ensures that if there is some offset built (maybe as there is so much E in fuels these days) that it potentially has no influence.

[gmh308]

I use .50 for my nat asp when calculating IBPWs for peak torque and since the AFR also used in the calc. would incorporate the correct the correct afr for the fuel used the E% should not matter for the BSFC . that is what I found in a few publications. So does Ethanol change the BSFC too? I may have found a sensor but I need to double check it later, my daughter just got here to visit.
98 tigershark

Hey TS, yes the BSFC changes for the ethanol content. As BSFC (imperial) units are pounds per horsepower hour, and with E85 ethanol there is around ~45% higher fuel flow, if the BSFC of an engine was 2lbs per horsepower hour on gas, then it may be something like 3 pounds per horsepower hour on E85.

(These are simplistic numbers as there are other characteristics of ethanol that mean that its BSFC could be more than a little higher than its mere energy content dictates, like the amount of oxygen it carries (35% by weight?) which supports a higher excess fuel level (PE), its heat of vaporisation (it cools more than gas as it vaporises), and its higher octane rating.)

FYI we found that with 42# injectors with E85 these would see duty cycle get into the mid 90's at 6000rpm (LS7), so they were virtually hitting the wall. There was no leaning out though at WOT so must certainly be on the edge there.

Fuel pump on that example was a 340lb per hour Walbro which is 42.5 lb per hour per injector so the fuel pump is around the end of its range as well.

Great thread guys! :)

[CalEditor]

LS7 GMPP Calibration Stoich Table
E % __ AFR Stoich
0 _____ 14.678223
6.25 __ 14.322266
12.5 __ 13.965820
18.75 _ 13.609863
25.00 _ 13.252930
31.75 _ 12.896973
37.50 _ 12.541016
43.75 _ 12.184082
50.00 _ 11.828125
56.25 _ 11.472168
62.50 _ 11.115234
68.75 _ 10.758789
75.00 _ 10.402832
81.25 _ 10.046875
87.50 _ 9.689941
93.75 _ 9.333984
100% _ 8.978027

[gmh308]

LS7 GMPP Calibration Stoich Table
E % __ AFR Stoich
0 _____ 14.678223
6.25 __ 14.322266
12.5 __ 13.965820
18.75 _ 13.609863
25.00 _ 13.252930
31.75 _ 12.896973
37.50 _ 12.541016
43.75 _ 12.184082
50.00 _ 11.828125
56.25 _ 11.472168
62.50 _ 11.115234
68.75 _ 10.758789
75.00 _ 10.402832
81.25 _ 10.046875
87.50 _ 9.689941
93.75 _ 9.333984
100% _ 8.978027

Gotta love the 6 SD accuracy of the calibration in these GM OS's. :)

[mr.prick]

http://www.zeitronix.com/Products/ECA/ECA.htm

If there is a table in the OS for stoich values, and you want to change it, simply change the first value - the 0% value. And optionally the second value. Why ? Have seen GM OS's (the ones with the tables) show the ethanol content as 3%, so setting the second value (6.25% ?) to your chosen stoichiometric AFR ensures that if there is some offset built (maybe as there is so much E in fuels these days) that it potentially has no influence.

Some OS' have only one value.
{B3601} (OS 12212156) is stuck to whatever you think you fuel will be.
There is no way for the PCM to change EQ1 for % of Ethanol.
I have read a few posts where some people have supposedly found away
around this with the older OS' but they offered no details.

[gmh308]

Some OS' have only one value.
{B3601} (OS 12212156) is stuck to whatever you think you fuel will be.
There is no way for the PCM to change EQ1 for % of Ethanol.
I have read a few posts where some people have supposedly found away
around this with the older OS' but they offered no details.

Correct. The stoich number needs to be changed in all of them to do this simply. The only OS's that use % ethanol are the flex fuel OS's with flex fuel enabled.

EFILive imposed limit is 10:1, but it allows lower numbers it seems with a "red" border on the cell which I guess means "beware".

Have made this stoich change on later OS's with positive results.

Sorry I thought you meant you had the table in 12212156. Just took a look at that with its single stoich number.

[CalEditor]

Have made this stoich change on later OS's with positive results.



Understatement
Look at the big picture. I use OSID 12611134 commonly and stoich is 14.569824 across the table. I am in a E10 area. Just correcting that makes the cars run better as if it was in an E0 area. Then do a like adjusting for the E10 in the EQ table and the PE table and WOW.
Customers seem to be very happy with just these adjustments.

[gmh308]

Understatement
Look at the big picture. I use OSID 12611134 commonly and stoich is 14.569824 across the table. I am in a E10 area. Just correcting that makes the cars run better as if it was in an E0 area. Then do a like adjusting for the E10 in the EQ table and the PE table and WOW.
Customers seem to be very happy with just these adjustments.

Great to hear! Yes its is unforunate that GM chooses not to leverage the potential of E10 even in their flex fuel vehicles. Leaving E10 as for E0.

What is 12611134 from?

[CalEditor]

Great to hear! Yes its is unforunate that GM chooses not to leverage the potential of E10 even in their flex fuel vehicles. Leaving E10 as for E0.

What is 12611134 from?

Northstar with a blower. :doh2:

If you knew me that would be a no brainer. I am one of the Northstar Guys, but I have started to step back from them and work with the other GM engines. :grin:
I am sooooooooooooooooo much happier

[98 tigershark]

Did you work with Dave Hill?

[Chevy366]

http://www.holdencrazy.com/EFILive/ , L59 is Flex Fuel - B3101 , B3103 , B3601 , B3695 , B3701 , B4001 .
COS3 or COS5 is easier .
Doesn't EFI University teach this in their EFILive courses ?

[98 tigershark]

I am from the northwest mountains, R U maken funnys bout ma skoulen. I only learned to read and write a few years tago. I aint gonna go ta no skoul nohow noway, it tukma tree yeas ta learn ha ta go on da intranote. A unavarsity is a skouls write? Ah kinda like EFILive cause u can luk at da pretty pictures. Ah wish a could draw like dat, Den ah might gonna get me real rich. Like Mr Paul. mr.prick an mr.ross told ma dat mr paul was da owner of da intranote an I baleave dem dudes. whats holden crazy anaways? a pliace were ya hold crazzie thangs. I got ma a fu tuns from thare 1nc and I liked da nice pictures ta louk at. Da they call it download cuz its frum downunda? I culd go thare if in it was fa free. Ah noes bout alcohol cuz I live in da mountains. I caint baleave ya all dodnt knows bout makin alcohol an puttin it in a automobile, evens ah knows bout dat. Did ah tell ya I live in da mountains? Ah caint rememba.
98 tigershark
P.S. I am pretty tired. Thanks for the PIDS, only problem is I only have V1 7.5.3.


http://www.holdencrazy.com/EFILive/ , L59 is Flex Fuel - B3101 , B3103 , B3601 , B3695 , B3701 , B4001 .
COS3 or COS5 is easier .
Doesn't EFI University teach this in their EFILive courses ?

[98 tigershark]

Ah sawed dat you goes ta wal mart. I has been thyre 1nc. I sees yall had a lil prproblem thear cuz ya saided "The Automated Checkout at Wal-Mart said "select method of payment" , I selected "IOU" , it refused to take it .". Guesses whats, I has an auto matic IOU thear sos whoes really needn skoul anyhows, sea ah tolds ya soo. Anys 1 shuold noes ya nead an autamated IOU,s at da wal Mart, cuz its so dang big thare caint be mo than 1 in the whole wide wold. Did ah telya I live in da mountains, an we doent have a skoul fo dat eathers. Ifen ya all needs helpen at da wal marts, ah wood (yah all can maken alcohol outa wood too,see I aint needen no skoulen) be glad ta help u, ifen u all maid it fo free.
98 tigershark


http://www.holdencrazy.com/EFILive/ , L59 is Flex Fuel - B3101 , B3103 , B3601 , B3695 , B3701 , B4001 .
COS3 or COS5 is easier .
Doesn't EFI University teach this in their EFILive courses ?

[gmh308]

Ah sawed dat you goes ta wal mart. I has been thyre 1nc. I sees yall had a lil prproblem thear cuz ya saided "The Automated Checkout at Wal-Mart said "select method of payment" , I selected "IOU" , it refused to take it .". Guesses whats, I has an auto matic IOU thear sos whoes really needn skoul anyhows, sea ah tolds ya soo. Anys 1 shuold noes ya nead an autamated IOU,s at da wal Mart, cuz its so dang big thare caint be mo than 1 in the whole wide wold. Did ah telya I live in da mountains, an we doent have a skoul fo dat eathers. Ifen ya all needs helpen at da wal marts, ah wood (yah all can maken alcohol outa wood too,see I aint needen no skoulen) be glad ta help u, ifen u all maid it fo free.
98 tigershark

ROFL! Saaayyyy whaaaatt y'aaallll!

[mr.prick]

L59 is Flex Fuel - B3101 , B3103 , B3601 , B3695 , B3701 , B4001 .
COS3 or COS5 is easier .
Doesn't EFI University teach this in their EFILive courses ?

Easier and cheaper than buying the $400+ sensor but
aren't they switchable, either or?
not true FF IMO.
How does the PCM know to change commanded EQ1 for % of ethanol?
L59 uses 1mb or 516kb PCM pick your poison. :)

[98 tigershark]

With what I have learned in this post has really opened my eyes. I am sure we can figure out a way to know. How much is the sensor GM uses and can a gauge be made or does one exist already? It is one thing to change your tune, but you really still do not know for sure what is in your tank. Reflashing the PCM every time you fuel up isn't to practical either.
AN example is I bought gasoline at a place that sells pure 94 octane gasoline ( a Shell station about 65 miles from my house) and went to the races. My injector duty cycles were acceptable, and everything seemed OK as far as the trims AFR etc.
When I bought E10 premium fuel and raced, my IBPWs increased enough to trouble me and the duty cycle did in fact increase by around 6% so there does seem an answer is there as the O2 sensors seemed to know something I didn't.
Has anyone else ever noticed this? It would also seem that until we can get a grip on this our tunes are not close enough to be safe. I am so glad for the help as I am looking for a new fuel pump and this has changed my decision. Lets keep working on this, you guys are experts and I am very excited to see how this gets resolved.
Going to school on the EFILive forum,
98 tigershark

[CalEditor]

You could figure out off of the O2 sensors, but I am under the impression that is a ton of work. I think Mopars do it that way.

This does not come with a Sensor
http://www.zeitronix.com/images/ECAx120.gif
Ethanol Content Analyzer (http://www.zeitronix.com/Products/ECA/ECA.htm)


or

Kost Moore Tools has a Fuel Composition Tester (J 44175) I use this tool to check fuel samples.
http://cgi.ebay.com/ebaymotors/GM-Kent-Moore-J-44175-Fuel-Composition-Alcohol-tester_W0QQitemZ370249443205QQcmdZViewItemQQimsxZ2 0090824?IMSfp=TL0908241610003r9255

You could use a setup like this from Dualflash.
http://www.dualflash.com.au/images/Products/IMG_1029%20v2-sm.JPG

http://www.dualflash.com.au/index.php?categoryid=10

[mr.prick]

There is a thread around here that someone was attempting to add
the sensor and use an FF OS,
I wonder if he got it going.

[Chevy366]

http://www.efi101.com/ On the left side 5 down , look what they teach , oh my God !
You guys crack me up seeing I have visited this over a year ago , have fun figuring out what I already know .
Got to go , my Kubota needs a oil change , and the cows need to be fed , I might wander on out to the still and grab me some of that ethanol to drink , and maybe pour some in the tank as well .
Hmm . pulse width modulation , what the Heck is that .

[98 tigershark]

Thanks CalEditor! That is some very good stuff.
That is one way to check every time you fill up the fuel Composition that is.
I looked at the Dual PCM and I think that is a very cool thing. But! we both know that we have to have a sensor in the tank that measures the Fuel composition in the tank and adjusts the AFR and their respective table in an on the fly fashion. Something kind of like a road runner except for the obvious automation that the PCM needs for immediate adjustments from the tank directly to the PCM and motor.
Currently we can:
1.)Have a few different tunes available to flash into the PCM for E10, E20, E30 and so on, But you have to be able to know test the fuel to know what tune to use.
2.)Go with 100% E85 and then replace most of the fuel system components (i.e. Pump, regulator, Injectors) as the stock parts on older Cars do not work well as to the needed increased fuel volume with the new E fuels.
3.) We can tune for E15 and learn to be happy with that. The E fuels is kind of like the 100% pure beef. The pumps say at least 10% ethanol or we use 100% pure gasoline. They do use 100% pure gasoline, But! They also use E10 plus 100% pure Gasoline. Spin!
The whole purpose of my tuning is to be as accurate as I could be with my EFILive and my WBO2 for economy, performance and regulations. Unless there is a constant Composition in the tank, the desired accuracy is just not there. In most cases not even close.
Now, Because of the current existence or the inevitable coming of different fuel I need to get a bigger than first thought fuel pump, Injectors and even a regulator. I think also that the E fuels kind of trick the O2 sensors a little, that is only my opinion as I am no expert. The new car requirements for pollution and our own personal requirements make it important that we figure this out in a practical accurate manner.

I suggest a fuel composition sensor in the tank that sends the correct stoich to the PCM, maybe through a small PCM that calculates this and than continually adjusts the appropriate tables in the factory PCM accordingly.
98 tigershark

[Chevy366]

There is a thread around here that someone was attempting to add
the sensor and use an FF OS,
I wonder if he got it going.
Didn't someone else explain how the newer OSs use STFT to detect Ethanol and make changes in the tune rather than using the sensor , think it was in the same thread .

[98 tigershark]

OK Chevy366,
I give up, I cant find the place that addresses the Earlier PCMs (non flex fuel) and Ethanol fuels. Can you please post the link, Pretty please. Before you visit your still would be nice. I had a tractor too (A Kiote), but my cows are now eaten. Pigs are much easier.
98 tigerhsark

[98 tigershark]

I have read a few articles on that as well but wasn't it determined to be not reliable with most all of the non flex fuel PCMs.
If I recall correctly, the Ethanol fuels can trick the O2 sensors and therefore the Long and short term fuel trims.
That was the conclusion right?
98 tigershark

Didn't someone else explain how the newer OSs use STFT to detect Ethanol and make changes in the tune rather than using the sensor , think it was in the same thread .

[mr.prick]

So STFTs change EQ1 in a GEN3 OS? :confused:
I don't recall reading how STFTs would detect what the Ethanol% is
therefore changing EQ1 automatically.
Newer OS' have a more defined stoich table per Ethanol%

The OP has a C5,
{B3601} is static with no way to change EQ1 for varying Ethanol%.
Example:
If EQ1 is set for gas (14.6AFR) and you have E10 (14.1AFR) in the tank
you are still going to command 14.6AFR not 14.1AFR and
all other fuel tables are stuck at the EQ settings based off {B3601} (14.6AFR)


Ideally, you just set your defined stoich point in the table to whatever the chemistry of your fuel really is and leave it alone. (I use 14.13 for e10, 14.64 for "normal" gasoline, and 14.4 to split the difference if we're unsure of what's in the tank)

This answered the original question.
If you want to run more than one fuel type/mixture things complicated
with a stock C5 OS,
it's either one fuel type or the other.

[gmh308]

Team,

It looks like GM's Virtual Fuel Sensing "technology" is being alluded to.

A few years ago GM announced that it had developed "Virtual" Fuel Sensing for Flex Fuel vehicles as an innovation that avoided the requirement for a "real" flex fuel sensor. The $700 list, $400 street sensor that sends fuel composition info to the PCM/ECM.

Read about the tech details on the "real" sensor here. It also details the FF GM vehicles the "real" sensor" is used on.

http://www.megamanual.com/flexfuel.htm

In short it provides a 50 - 150Hz square wave to the PCM/ECM to indicate ethanol content, and is smart enough to detect fuel contamination, and indicates fuel temperature via modulating the pulse width of the square wave.

The operation of GM's Virtual Sensor (VFS) is described in the GM patent
attached in "patent speak". Enjoy the read :shock:.

6125

In short "it" uses fuel tank level changes to decide the tank has been filled and runs a cycle using the O2 sensors & trims to help decide what the E content is and then references various other E tables in the PCM/ECM to get the timing and the fueling optmised for E.

Interesting stuff. :)

[CalEditor]

Team,

In short "it" uses fuel tank level changes to decide the tank has been filled and runs a cycle using the O2 sensors & trims to help decide what the E content is and then references various other E tables in the PCM/ECM to get the timing and the fueling optmised for E.

Interesting stuff. :)

I am under the impression that the fuel level sensor need to be connected on conversions also to switch back to the High octane table. If you have a conversion with out a fuel level sensor you will be stuck on the low octane table. :doh2:

funny how GM uses that sensor for more than just the EVAP system. :sly:

[gmh308]

I am under the impression that the fuel level sensor need to be connected on conversions also to switch back to the High octane table. If you have a conversion with out a fuel level sensor you will be stuck on the low octane table. :doh2:

funny how GM uses that sensor for more than just the EVAP system. :sly:

If you log the Octane scaler, and it is above zero, you will see it ramp back down over time towards zero. Sometimes this occurs quickly, sometimes not. Seems to depend on frequency and severity of knock. Which makes good sense. :)

[98 tigershark]

That is pretty cool stuff. Thank you so much. I had seen some thing like this awhile back last year. Didn't they have a separate fuel tank specification that was patented separately but must be used with this system? I think is was a sort of chopped top of pyramid style tank. I am going off of memory here so take that for what it is. Do you know anything about the special tank for this, I heard only heard of this but I think it is true. What say you gmh308? gm General manager? So what do we do?
Thanks again as that is really cool. I am curious as to how you found that,
Very grateful,
98 tigershark

[Chevy366]

OK Chevy366,
I give up, I cant find the place that addresses the Earlier PCMs (non flex fuel) and Ethanol fuels. Can you please post the link, Pretty please. Before you visit your still would be nice. I had a tractor too (A Kiote), but my cows are now eaten. Pigs are much easier.
98 tigerhsark
Sorry , I think I used 'Ethanol sensor' in search criteria . Try that , if not I will see if I can find it again .
Oh , watch the country hick comments , not funny !

[98 tigershark]

Hey Sorry Chevy366,

I do have a tractor, I did raise cows and I do occasionally raise pigs and I have a small farm.
Even though I have never hunted from my deck I could!!
I do live in the sticks and I like Jeff Foxworthy, I think I got his name right.
We are a little sensitive today so sorry! Because I live in the sticks it is hard to get good gas and diesel.
Thanks,
98 tigershark


Sorry , I think I used 'Ethanol sensor' in search criteria . Try that , if not I will see if I can find it again .
Oh , watch the country hick comments , not funny !

[98 tigershark]

See My tractor in the background!

[CalEditor]

I will trade you my place in city next to Harley Davidson's R&D head quarters for your place in the NW any time. Then I would be set. My little shack in Rock Hill SC and a place in the Good Old NW. I could actually go visit friend and relatives for a change.

[CalEditor]

You would have to leave the Tractor

[98 tigershark]

I saw that you are from Washougal. I like Washougal. I live 45 miles east on the WA side and then up in the mountains.
I think that Chevy366 thinks that I was making fun of Country folk because of the granola head label you get from fox news about the NW. I don't think he knows how many of us country folk there are in or from the NW.
BTW there is a somewhat new tuning outfit in Washougal I have heard some Ok things about.
I run into some of there customers at the races. One guy has a 07 ZO6 that he claims has 630 RWP dynoed by them. Thats around 700 hp+ at the crank on E85. His only improvement are a cold air intake, Headers and a Cam and only E85. LS7 injectors cant handle that not even close. Your earlier post (and link) in this thread exposes the guys that make these types of claims. There is no way the fuel system, pump, injectors especially can support that on E85.
I do not know if it is the tuning shop or the customers as I have heard good things about the shop. We just do not have very many tuners out here in the NW and you could do very well here. Something to consider! Also allot of us hot rod guys out here have Harleys too.
Maybe we could get Chevy366 to move out here too!
Take care in the City,
98 tigershark

[gmh308]

I run into some of there customers at the races. One guy has a 07 ZO6 that he claims has 630 RWP dynoed by them. Thats around 700 hp+ at the crank on E85.

His only improvement are a cold air intake, Headers and a Cam and only E85. LS7 injectors cant handle that not even close. Your earlier post (and link) in this thread exposes the guys that make these types of claims. There is no way the fuel system, pump, injectors especially can support that on E85.
98 tigershark

I can vouch for that...the standard injectors on an LS7 are hitting the wall at 500HP crank on E85.

[CalEditor]

I worked for Nutter Racing Engines for a few years before moving to Wisconsin. I have friends in Stevenson, Carson, and White Salmon along with Washougal, Camas, Vancouver, and Portland. Back in the early 90's I did a lot of work for a guy with a orange 70 Road Runner and a 76 T-Bird that was in Carson at the time. I think he is in White Salmon now.

I need to do the Math on the Theoretic HP for fuel blends. It is all math so it should be very hard to do a spread sheet. E85 or E100 just simply has more BTU's per volume. End of story.

[98 tigershark]

Correctamoondo!!

[CalEditor]

These are E85 compatible Delphi injectors
They look a little different and some flow a ton.
http://i224.photobucket.com/albums/dd25/AJxtcman/Injectors/DelphiINJ.jpg

[gmh308]

These are E85 compatible Delphi injectors
They look a little different and some flow a ton.
http://i224.photobucket.com/albums/dd25/AJxtcman/Injectors/DelphiINJ.jpg

Cool. Apart from flow rate, it would be interesting to know whether they do actually use different materials to the regular current injectors.

I pulled my gas tank yesterday to check on a possible leak and at the same time, as there has been a lot of E85 through the tank, checked for corrosion effects.

There is bare steel in the tank on the sender bracket. No corrosion. Just normal bare metal. No evidence of any effect in the 8 months running E85 and mixes. The tank should be fine for a long time. Stainless from Rock Valley/DSE. :)

[chevy052500hd]

Cool. Apart from flow rate, it would be interesting to know whether they do actually use different materials to the regular current injectors.

I pulled my gas tank yesterday to check on a possible leak and at the same time, as there has been a lot of E85 through the tank, checked for corrosion effects.

There is bare steel in the tank on the sender bracket. No corrosion. Just normal bare metal. No evidence of any effect in the 8 months running E85 and mixes. The tank should be fine for a long time. Stainless from Rock Valley/DSE. :)

I think engineers are over engineering the fuel systems for that what if situation. I have ran e85 on my s-10 non flex fuel truck with a 4.3l for over a year had no problems what so ever. Truck is still running it today.

[mr.prick]

Did you tune it for E85?

[chevy052500hd]

yep did tune the pcm for e85

[Chalky]

has anyone determiend the proper formula for setting up a WB pid for E10?

[98 tigershark]

I think SSdDmon was starting to so I hope he continues that post. It looked like he uses Innovative also as I do. That is a tricky deal I think from what we have learned. Mybe Paul and Ross can change the install instructions for the EFILive LC1 in their tutorials.
Glad you re brought that up.
Thanks,
98 tigershark

[mr.prick]

has anyone determiend the proper formula for setting up a WB pid for E10?

Why would this need to be changed?
All you have to do is change EQ1 AFR for your fuel type
and all the other fuel tables will automatically change because
they are actually EQ.
Just make sure you enrichment EQ is right.

Using a Lambda based multiplier could be problematic
if your WBO2 setting for Lambda1 does not match EQ1 exactly.

[Chalky]

Fact is I do not know. PID formula for PLX is AFR={ext.ad1}*2+10.

I am not sure this formula is valid with anything other than 14.68! SSpdDOM implied that formulas would have to change if using anything other than 14.68

It would seem that if I set B3601 to 14.11, my wb would treat 14.11 as stoich but I just wanted to tap the knowledge base here to be sure.

[Chalky]

While we are on the subject, let me ask a question about e10 and AFR. This may have a simple answer but I cannot make heads or tails of it.

Example, LS1/LS6 ECM's used 14.68 as stoich which would imply that GM felt non-E fuel would run through the car or worst case, E10 fuel with a stoich 14.68 was still within margin of error. This is my conclusion and is seems reasonable.

When you look @ PE table B3618, AFR range is approx 11.8 to 12.6. This rich by normal fuel standards but almost ideal for E10 fuels in terms power making ranges.

Could this have been a GM failsafe for addressing non ethanol and E10 markets as a compromise? Appreciate any feedback on this. I may be in left field but is seems reasonable to me anyway.

[SSpdDmon]

has anyone determiend the proper formula for setting up a WB pid for E10?

Personally, I use an LM1. In the Innovate software, you can customize the analog output to read whatever you'd like. When you program it, you can do so using Lambda or AFR numbers. Straight from the instructions, it says this doesn't change anything - just the representation of the data. So...from there you need to decide what you want to work with. Then, you can program the sensor and set your PIDs.

If you want to work with AFR, you could program the following:
GAS=14.64.....0v=10.84.....5v=17.22....."({EXT.AD1}*1.276)+10.84"
E10=14.07.....0v=10.42.....5v=16.55....."({EXT.AD1}*1.226)+10.42"
E85=9.77.....0v=7.24.....5v=11.49....."({EXT.AD1}*0.851)+7.24"

(All of the above are 0v=1.35 EQ and 5v=.85 EQ)

The equations are easy. The EXT.AD1 multiplier is simply the difference between your 5v and 0v values (5v-0v=difference) divided by the voltage spread (5v). So, for gas it was (17.22-10.84)/5=1.276. Then, you just add the 0v number on the end (outside of the brackets).

For logging EQ PIDs using those same AFR's (which translate into Lambdas of 0v=0.74074 & 5v=1.1765), the equation is a little more difficult. This is because EQ & Lambda aren't linear. A little Excel work and I came up with this equation:

EQ___0.0___2.0___"(-0.0008*({EXT.AD1}+1)*({EXT.AD1}+1)*({EXT.AD1}+1))+ (0.0179*({EXT.AD1}+1)*({EXT.AD1}+1))-(0.1895*({EXT.AD1}+1))+1.5223"

Someone will have to test that puppy out and see if it's right...and it's not going to be me this week (too much going on). :) Ideally, using those lambda numbers along with this PID equation, you should be able to disregard the AFR readout on the screen of the sensor. This means that, if I've done my math correctly, it won't matter what fuel is in the tank. If the sensor reads the mixture in terms of Lambda/EQ, this equation should back into the voltage output to provide you a stoich reading. In this case when EXT.AD1=2.975, you should be at stoich no matter what fuel type. When EXT.AD1=1.658, you should be at 1.13 EQ regardless of fuel type. And so on...

[mr.prick]

Example, LS1/LS6 ECM's used 14.68 as stoich which would imply that GM felt non-E fuel would run through the car or worst case, E10 fuel with a stoich 14.68 was still within margin of error. This is my conclusion and is seems reasonable.
Actually it is 14.63AFR = 1% Ethanol



When you look @ PE table B3618, AFR range is approx 11.8 to 12.6. This rich by normal fuel standards but almost ideal for E10 fuels in terms power making ranges.

Could this have been a GM failsafe for addressing non ethanol and E10 markets as a compromise? Appreciate any feedback on this. I may be in left field but is seems reasonable to me anyway.

Most likely for cat protection.
{B3601} set to 14.63AFR and the small fuel injectors
tell me that the LS1 was not meant for Ethanol.

[Chalky]

02 and later LS6 used 14.68 as stoich.

LS1/6 also had CAT protection, B0701.

[mr.prick]

02 and later LS6 used 14.68 as stoich.

LS1/6 also had CAT protection, B0701.

I'm stuck on the OP's OS. :doh2:
What I meant was the lower AFR would help to keep them from getting into
CAT protection mode/AFR not for actual CAT overtemp protection.

14.63 or 14.68 either way Ethanol was not meant for stock LS1
I agree with you.

[Chalky]

Maybe I can ask this another way:

If B3601 is set to 14.68 and PE flatlined @ 12.6, you run non ethanol fuel, car will be happy under fuel power as we recognize 12.6 +/- to be a excellent power.

Now same conditions but we run E10 through car with no changes, would this not be a lean condition for E10 fuel?

FWIW, I always tuned in AFR, never used EQ or lambda. After listening to SSpdDmn and reviewing Greg Banish's video, I finally realized I needed to change methods.

[mr.prick]

Yes,
If {B3601} is static(one value) you are stuck with that.
Example:
If it is set for gas(14.7=EQ1) and you put in E10 in the tank
there is now way for the PCM to know or change EQ1 for E10(14.1),
it is going off of the static value of 14.7(EQ1) when it should change to 14.1
and PE will be stuck at 12.6(EQ1.17) when it should be lower.

If you change {B3601} and save your tune then reopen it you will see
{B3618} changed because it is actually in EQ only,
the software converts it to AFR.

This whole thread is about a static {B3601}
not newer OS' with a 2D table based on Ethanol percentage.
:Nothing_funny_to_ad

[98 tigershark]

mr.prick is right. read through this thread from the front to the back, I think it will really help you and its free.
It is very good stuff and it helped me.
98 tigershark

[98 tigershark]

Exxon/Mobile or is it Chevron that says it is Techrolean. Enriched with Techrolean to be exact. The 1% is Techrolean in Exxon/Mobile or the Chevron fuel I gorget which one. Nanner nanner nanner!! mr.prick
Love to say that,
Regards,
98 tigershark


Actually it is 14.63AFR = 1% Ethanol



Most likely for cat protection.
{B3601} set to 14.63AFR and the small fuel injectors
tell me that the LS1 was not meant for Ethanol.

[SSpdDmon]

Updated previous post with pics...

http://forum.efilive.com/showthread.php?p=103534#post103534

[CalEditor]

Yes,
If {B3601} is static(one value) you are stuck with that.
Example:
If it is set for gas(14.7=EQ1) and you put in E10 in the tank
there is now way for the PCM to know or change EQ1 for E10(14.1),
it is going off of the static value of 14.7(EQ1) when it should change to 14.1
and PE will be stuck at 12.6(EQ1.17) when it should be lower.
If you change {B3601} and save your tune then reopen it you will see
{B3618} changed because it is actually in EQ only,
the software converts it to AFR.

This whole thread is about a static {B3601}
not newer OS' with a 2D table based on Ethanol percentage.
:Nothing_funny_to_ad

What do you think the PE AFR should be set to with E10?

[mr.prick]

According to your spreadsheet (http://forum.efilive.com/showpost.php?p=103113&postcount=52) 12.1275 AFR

[98 tigershark]

The newer PCMs say 14.07.
Ha Ha HA, You got mr.prick to stay on this thread. I am glad as he always stays on course!! I mean that as a compliment too. But that is a very good question also because it is more than just the E%. When are we going to get around to the Spark aand Timing issues too and what that does to the AFR with the E fuels and the vaporization issues and spark and flash. No mater what the E fuel% is, the motor seems to pick its spot as far as timing regardless of what is commanded, and timing does affect how the actual AFR is obtained also, Since that is static, something is tricking the PCM, How can this be and how do we adjust spark for the correct AFR in B3601? My logging says it is right today(new gas from Portland), but, I put an old fashioned timing light on the HB and it says it is different than the PCM is commanding this weekend. I had that happen before and it is not a loss reluctor. Is the PCM is commanding the right timing or just showing it that way when I log. In other words do the E fuels trick the PCM as that is all I can think of as that has to change the commanded AFR also??? Really!
98 tigershark


According to your spreadsheet (http://forum.efilive.com/showpost.php?p=103113&postcount=52) 12.1275 AFR

[CalEditor]

This is an 05 Flex fuel stock bin file. 6153

[Chalky]

Yes,
If {B3601} is static(one value) you are stuck with that.
Example:
If it is set for gas(14.7=EQ1) and you put in E10 in the tank
there is now way for the PCM to know or change EQ1 for E10(14.1),
it is going off of the static value of 14.7(EQ1) when it should change to 14.1
and PE will be stuck at 12.6(EQ1.17) when it should be lower.

If you change {B3601} and save your tune then reopen it you will see
{B3618} changed because it is actually in EQ only,
the software converts it to AFR.

This whole thread is about a static {B3601}
not newer OS' with a 2D table based on Ethanol percentage.
:Nothing_funny_to_ad

I am aware of this. My point being did GM set the PE table up as unusually rich or were they acknowledging the fact that many cars would see E10 and set up PE tables to acknowledge a rich non-ethanol AFR or a damn close PE for E10.

[98 tigershark]

I set up my car making it think it had larger injectors by about 6%. You would think since B3601 is static that the IBPWs should be smaller and the AFR way off. Under the PE/RPM table the IBPWs were more, they should have been less and run lean. The PE AFR was the almost the same and the commanded Tuned/Logged timing logged a higher than actual when checked with a timing light on the HB. I am switching to LAMBDA for the most part and did not get this finished as planned. But this I know, The PCM does seem to be able to be tricked. I have no clue how this happens as the trims were almost the same. In 97-98 Vette PCMs are set up to run rich stock @62psi Inj pressure so I would buy your theory for those years but that was changed to a leaner condition from 99 on @58 psi and Inj flow accordingly.
Go Figure,
98 tigershark



I am aware of this. My point being did GM set the PE table up as unusually rich or were they acknowledging the fact that many cars would see E10 and set up PE tables to acknowledge a rich non-ethanol AFR or a damn close PE for E10.

[mr.prick]

I am aware of this. My point being did GM set the PE table up as unusually rich or were they acknowledging the fact that many cars would see E10 and set up PE tables to acknowledge a rich non-ethanol AFR or a damn close PE for E10.

:nixweiss:
Your guess is as good as mine.
An '02 Fbody Stoich setting is close to gas
and the max PE value is closer to E22 according to the spreadsheet. (http://forum.efilive.com/showpost.php?p=103113&postcount=52)

A lean stoich for E10 and
and way rich PE for gas.

An '02 Ybody(zo6) seems to be a different story
According to the spreadsheet (http://forum.efilive.com/showpost.php?p=103113&postcount=52) stoich setting is gas
and PE is right on for E10.
:nixweiss:


An email to the CEO of GM may get a definitive answer to your question.
(http://www.whitehouse.gov/CONTACT/)

[98 tigershark]

I dont know but maybe the MAP advances the spark also to adjust, but that is just a guess.
98 tigershark

[SSpdDmon]

What's the point of worrying about what was meant by a GM engineer? If it was tuned for gas, then E10 would cause a rise in fuel trims, which would ideally be carried over to WOT. So (in theory), PE would be back to it's rich levels originally set by the engineers. Truth is, the real world isn't as consistent as the lab (no matter how high tech it is), some gas stations sell bad gas (whether they know it or not), and warranty costs have not only a negative cost impact, but a negative effect on an OEM's reputation. To me, it goes without saying that they're going to tune the OEM setup on the conservative side.

[98 tigershark]

Here is a new one on me. Today I put gas in my tanK from a place in Portland that I know for sure has E10 and 90% Gasoline.. My car ran tremendously better and was happy. So on the way home today I bought a gallon of Premium from a station that I filled up before. I asked the owner this Question and very carefully:
Q:Were can I buy E85 as I wished we had a station that sells it around here as the Octane is really good for my care and worth as much as E10 Gas?

A:They said we get E85 (also that sometimes its a little old so they get a good deal) from a whole seller when the other prices are too high during the summer and holiday seasons. Also to ask so I could get the right pump. E85 is 2/3 ( instead of $3.00+ a gal, E85 is 2.00 a gal) the price of E10 so do I trust a little station now in this economy, no!!

What can I say. I could tell my car was not running well and the fuel milage was terrible also. It even sounded lean and the timing was off. When I refilled today, my car was very happy. So here is the big deal. That could have toasted my engine and If I had paid a local tuner for an $800.00 tune it would be worthless as it was done with E85 not E0-E10. I could have also done allot of other damage. Almost double the consumption and a very sissy like sound and throttle response and the timing was somehow not as commanded.
You see not just because it is B3601, But anything higher than E10 can cause damage and even wasted money on an expensive tune or a voided warranty. I was pretty sure it was very bad fuel but it did drive me crazy as I think my car is pretty darn fast and it was a sissy mobile.
I am going to try to get a system in my car this winter to know, as I have to much time and money invested to let a gas station or a distributor or an honest mistake even ruin my car.
Thanks SSpdDmon as you are on solid ground with the known part, but you missed an important point because you are honest. Unfortunately that does not mean everyone is or perfect!! We have to find a way on the fly!!
Something to think about.
98 tigershark

[SSpdDmon]

Here is a new one on me. Today I put gas in my tanK from a place in Portland that I know for sure has E10 and 90% Gasoline.. My car ran tremendously better and was happy. So on the way home today I bought a gallon of Premium from a station that I filled up before. I asked the owner this Question and very carefully:
Q:Were can I buy E85 as I wished we had a station that sells it around here as the Octane is really good for my care and worth as much as E10 Gas?

A:They said we get E85 (also that sometimes its a little old so they get a good deal) from a whole seller when the other prices are too high during the summer and holiday seasons. Also to ask so I could get the right pump. E85 is 2/3 ( instead of $3.00+ a gal, E85 is 2.00 a gal) the price of E10 so do I trust a little station now in this economy, no!!

What can I say. I could tell my car was not running well and the fuel milage was terrible also. It even sounded lean and the timing was off. When I refilled today, my car was very happy. So here is the big deal. That could have toasted my engine and If I had paid a local tuner for an $800.00 tune it would be worthless as it was done with E85 not E0-E10. I could have also done allot of other damage. Almost double the consumption and a very sissy like sound and throttle response and the timing was somehow not as commanded.
You see not just because it is B3601, But anything higher than E10 can cause damage and even wasted money on an expensive tune or a voided warranty. I was pretty sure it was very bad fuel but it did drive me crazy as I think my car is pretty darn fast and it was a sissy mobile.
I am going to try to get a system in my car this winter to know, as I have to much time and money invested to let a gas station or a distributor or an honest mistake even ruin my car.
Thanks SSpdDmon as you are on solid ground with the known part, but you missed an important point because you are honest. Unfortunately that does not mean everyone is or perfect!! We have to find a way on the fly!!
Something to think about.
98 tigershark
I'm confused...did you just throw old E85 in the tank and didn't bother to change B3601? Outside of the fact that the station owner admitted to the gas being old, did you make sure you have enough injector to support a higher blend of ethanol before hand? If it's not getting enough fuel and/or the timing wasn't adjusted, then yes it's going to run like a wimp.

We all need to make sure that focusing on the tune so much doesn't make us forget about the mechanical side of things. If you don't have enough injector to support a higher blend of ethanol...then playing around with E85 is probably not such a good idea.

[98 tigershark]

I did not know that was the case as to the gas until I asked later, yesterday as a matter of fact, I thought I had bought E10 as that is what it said on the pump on the previous fill. Not E85 as it turned out!! The point is that how do you know what is in the tank? In this case the station put E85 in the E10 tanks and sold E85 for the price of E10 and in an E10 pump. They admitted it. Because they got a good deal on it. Think about that. A station 10 or 30 times a year puts E85 in the E10 tanks. If the Station tanks are around 10,000 gallons, thats an extra $10,000 they make if they sell it as E10 when it should be sold as E85. If they do this 10 times a year they have made $100.000.00 extra. Then suddenly a small struggling station or a crooked one or a fuel distributor, or just an honest mistake, whatever the situation is, selling E85 in the E10 pumps has to be happening more and more. And you are right I am worried about the damage and the mechanical aspect. I would never put E85 in my tank knowingly, as my setup can barely handle E10 as to the 40% plus volume requirements needed for E85. I was pretty ticked off when they said they do this sometimes. Would most of the public notice this, probably not. So they can get away with it. I am not even sure if it is legal. But the extra profit will surely make this kind of thing happen more!
Thanks SSpdDmon as you are right I am concerned about the mechanical side. The point was this kind of thing will happen more and more I think.
Take care,
98 tigershark

[SSpdDmon]

I did not know that was the case as to the gas until I asked later, yesterday as a matter of fact, I thought I had bought E10 as that is what it said on the pump on the previous fill. Not E85 as it turned out!! The point is that how do you know what is in the tank? In this case the station put E85 in the E10 tanks and sold E85 for the price of E10 and in an E10 pump. They admitted it. Because they got a good deal on it. Think about that. A station 10 or 30 times a year puts E85 in the E10 tanks. If the Station tanks are around 10,000 gallons, thats an extra $10,000 they make if they sell it as E10 when it should be sold as E85. If they do this 10 times a year they have made $100.000.00 extra. Then suddenly a small struggling station or a crooked one or a fuel distributor, or just an honest mistake, whatever the situation is, selling E85 in the E10 pumps has to be happening more and more. And you are right I am worried about the damage and the mechanical aspect. I would never put E85 in my tank knowingly, as my setup can barely handle E10 as to the 40% plus volume requirements needed for E85. I was pretty ticked off when they said they do this sometimes. Would most of the public notice this, probably not. So they can get away with it. I am not even sure if it is legal. But the extra profit will surely make this kind of thing happen more!
Thanks SSpdDmon as you are right I am concerned about the mechanical side. The point was this kind of thing will happen more and more I think.
Take care,
98 tigershark
Ohhh....I got ya now. Yeah, I wouldn't be visiting that station anytime in the future. I'd be willing to bet there's a way to report them. That's definitely not good that they're selling something other than what's advertised.

[98 tigershark]

Now you have it. Think about the extra profit they make too. I am not sure how to report them or even if this is against the law. In small towns we just stay away and be careful what we say as everyone is related almost or at least friends.
Take care,
98 tigershark

[mr.prick]

You should of filled up with Techron. ;)

[98 tigershark]

You are soooo right!!!
Techrolean, I like techrolean!!!
98 tigershark

[SSpdDmon]

Personally, I use an LM1. In the Innovate software, you can customize the analog output to read whatever you'd like. When you program it, you can do so using Lambda or AFR numbers. Straight from the instructions, it says this doesn't change anything - just the representation of the data. So...from there you need to decide what you want to work with. Then, you can program the sensor and set your PIDs.

If you want to work with AFR, you could program the following:
GAS=14.64.....0v=10.84.....5v=17.22....."({EXT.AD1}*1.276)+10.84"
E10=14.07.....0v=10.42.....5v=16.55....."({EXT.AD1}*1.226)+10.42"
E85=9.77.....0v=7.24.....5v=11.49....."({EXT.AD1}*0.851)+7.24"

(All of the above are 0v=1.35 EQ and 5v=.85 EQ)

The equations are easy. The EXT.AD1 multiplier is simply the difference between your 5v and 0v values (5v-0v=difference) divided by the voltage spread (5v). So, for gas it was (17.22-10.84)/5=1.276. Then, you just add the 0v number on the end (outside of the brackets).

For logging EQ PIDs using those same AFR's (which translate into Lambdas of 0v=0.74074 & 5v=1.1765), the equation is a little more difficult. This is because EQ & Lambda aren't linear. A little Excel work and I came up with this equation:

EQ___0.0___2.0___"(-0.0008*({EXT.AD1}+1)*({EXT.AD1}+1)*({EXT.AD1}+1))+ (0.0179*({EXT.AD1}+1)*({EXT.AD1}+1))-(0.1895*({EXT.AD1}+1))+1.5223"

Someone will have to test that puppy out and see if it's right...and it's not going to be me this week (too much going on). :) Ideally, using those lambda numbers along with this PID equation, you should be able to disregard the AFR readout on the screen of the sensor. This means that, if I've done my math correctly, it won't matter what fuel is in the tank. If the sensor reads the mixture in terms of Lambda/EQ, this equation should back into the voltage output to provide you a stoich reading. In this case when EXT.AD1=2.975, you should be at stoich no matter what fuel type. When EXT.AD1=1.658, you should be at 1.13 EQ regardless of fuel type. And so on...

OK...so I lied. I made the custom PID & tested the formula using an old log I had AND.....drum roll please......it works. :)

[98 tigershark]

Thanks for doing that. Does the custom PID formula work on EFILive V1? I have never made a custom PID and before now really did not need or want to.
And is that the same one posted. Anyway thanks a bunch as that had to take some time so I appreciate that.
98 tigershark

[mr.prick]

I'm not seeing the point of this PID.

If you want to replace AFR with EQ
{B3601}/AFR = EQ
For Lambda
14.7/{B3601} = Lambda
Replace 14.7 with the multiplier your WBO2 uses.

[5.7ute]

I'm not seeing the point of this PID.

If you want to replace AFR with EQ
{B3601}/AFR = EQ
For Lambda
14.7/{B3601} = Lambda
Replace 14.7 with the multiplier your WBO2 uses.

Dont you mean AFR/{B3601} = Lambda?

[mr.prick]

Dont you mean AFR/{B3601} = Lambda?

I F&*@$! that up.
:doh2:

I meant AFR/14.7 = Lambda
{B3601} does not match my WBO2 setting for Lambda1.
EQ1 = 14.63
Lambda1 = 14.7
This is why I am sticking with AFR/EQ.

Thanks for catching that.

[SSpdDmon]

98 -

I use V1. :)


I'm not seeing the point of this PID.

If you want to replace AFR with EQ
{B3601}/AFR = EQ
For Lambda
14.7/{B3601} = Lambda
Replace 14.7 with the multiplier your WBO2 uses.

The point is, it works regardless of the stoich AFR point of the fuel in the tank or the setting in B3601 because it's going off of the voltage input from the sensor. The sensor reads lambda. Then we use a bunch of equations to convert to AFR. So, you can convert it back and forth around an assumed AFR or you can go off of EQ straight from the sensor. I like it because even if you don't know exactly how much ethanol is added, you can still get an accurate enrichment figure.



The attached calc_pids.txt file has the PID all set up. It's been tweaked to span 0v=0.75Lambda and 5v=1.09Lambda (gasoline AFR span of 11:1-16:1).

[98 tigershark]

Hey mr.prick/SSpdDmon

It does seem that some things are a mute issue but I think this PID if I understand it correctly will help me as to the fuel. I think that is going to become a very big deal if not already. Mr P Dont forget you use fuel enriched with Techron. 1% or so,=14.63.
nanner nanner nanner!!
SSpdDmon, thanks for the PID, I will use it, thanks as I said I have not made any Custom PIDs, I dont call setting up the LC1 when originally programing a custom PID. It seems like this one really works and has sparked my interest into those, so thanks.
Thanks for the PID
98 tigershark

I F&*@$! that up.
:doh2:

I meant AFR/14.7 = Lambda
{B3601} does not match my WBO2 setting for Lambda1.
EQ1 = 14.63
Lambda1 = 14.7
This is why I am sticking with AFR/EQ.

Thanks for catching that.

[SSpdDmon]

Hey mr.prick/SSpdDmon

It does seem that some things are a mute issue but I think this PID if I understand it correctly will help me as to the fuel. I think that is going to become a very big deal if not already. Mr P Dont forget you use fuel enriched with Techron. 1% or so,=14.63.
nanner nanner nanner!!
SSpdDmon, thanks for the PID, I will use it, thanks as I said I have not made any Custom PIDs, I dont call setting up the LC1 when originally programing a custom PID. It seems like this one really works and has sparked my interest into those, so thanks.
Thanks for the PID
98 tigershark
Remember, you need to reprogram your LC1 so that 0v=0.75Lambda and 5v=1.09Lambda for that equation to be accurate.

[98 tigershark]

Thanx for the mentoring.
It is very much appreciated.
98 tigershark

[CalEditor]

Real Case Scenario

05 Escalade came in with DTC's P0171 & P0174 Both banks lean.
Technician A thinks it has a bad MAF- he swapped the MAF out same results
Technician B thinks it has a leaking intake gsk and or warped intake (per TSB)
Technician C (myself) Asked what the MAF reading was at idle. Technician B states 7.XX g/sec. Technician C states that it has E85 in it or very low fuel pressure, but it has to be E85.

Technician A test the fuel Quality and find E70 in the tank.

The MAF reading is the diagnostic needed to figure this out. If the Maf was 4.xx g/sec it would have been a intake leak. 7 to 8 g/sec is about normal for this engine. This is a stock setup with no mods, so that means with the 7.XX g/sec the injectors are flowing the correct amount. With the exception of low fuel pressure, but we know that isn't the issue.

[98 tigershark]

Hello CalEditor,
Thats cool. Just wondering if the customer knew he or she bought E85 or was it a fuel at the station switch? Did they Charge the for a new MAF. LOL
98 tigershark

[CalEditor]

Actually I was by Technician B's area and saw an LS1 MAF on his bench and asked why it was off the car he was working on. He said Technician A asked to try it on the Escalade he was working on, so No they were not charged for it

[98 tigershark]

Did the customer know he had E85? I was kidding about the MAF charge, I have a pretty decent Idea that you would never be around a place that does that. ANd I mean that as a very high compliment.
98 tigershark

[CalEditor]

Did the customer know he had E85? I was kidding about the MAF charge, I have a pretty decent Idea that you would never be around a place that does that. ANd I mean that as a very high compliment.
98 tigershark

NO and from my understanding GM says to run the tank out now. You don't need to drain and refill anymore. :hihi:

[CalEditor]

funny thing was to me I was telling Technician B that it is all math and he was looking at me strange.

Fuel Flow Rate = MAF X desired AFR

7.xx g/sec@ idle is stock, the Injectors are stock, tune is stock, and the truck is running so the fuel pressure is close to stock. Then it has to have E85 in the tank.


We only have one fuel pump issue period
That would be on the ESV's. The line in the tank rubs on the tank module and it gets a small hole in it, but that makes for a hard start.
I just know from experience the pump was A OK and it was.

[joecar]

Did you mean this:

Fuel Flow Rate = MAF * FAR = MAF / AFR

:)

[98 tigershark]

Hey Joe,

How have you been/ Well I hope and the Cat thing is ok now, i hope.

I think it goes like this.
Fuel Flow Rate= MAFxAFR(stioch)=MAF/AFR(stioch) and assumes gasoline stioch for the type of non flex fuel vehicles PCM?
Is this correct?


Did you mean this:

Fuel Flow Rate = MAF * FAR = MAF / AFR

:)

[98 tigershark]

Hey guys,
This has been a great learning thread for me so thank you.
I stumbled upon an article today that really helped me understand the bigger picture of all fuels including gas.
Especially with the new Flex fuel cars and the VVT, VE, Coefficients, the Zones spark and on and on. It is attached and is an easy read.
After reading this I might even try to mix a little water with ethanol.
Take a look at the attachment and let us know if this help better understand the newer systems. It did occur to me that they thermal zones I think and their coefficients as to vaporization of whatever fuel we are using. A thermal Zone and VE WOW!! Plus it show the energy potential and advatges and disadvantages. Even VE and stoich!!
98 tigershark

[Chevy366]

I saw that you are from Washougal. I like Washougal. I live 45 miles east on the WA side and then up in the mountains.
I think that Chevy366 thinks that I was making fun of Country folk because of the granola head label you get from fox news about the NW. I don't think he knows how many of us country folk there are in or from the NW.
BTW there is a somewhat new tuning outfit in Washougal I have heard some Ok things about.
I run into some of there customers at the races. One guy has a 07 ZO6 that he claims has 630 RWP dynoed by them. Thats around 700 hp+ at the crank on E85. His only improvement are a cold air intake, Headers and a Cam and only E85. LS7 injectors cant handle that not even close. Your earlier post (and link) in this thread exposes the guys that make these types of claims. There is no way the fuel system, pump, injectors especially can support that on E85.
I do not know if it is the tuning shop or the customers as I have heard good things about the shop. We just do not have very many tuners out here in the NW and you could do very well here. Something to consider! Also allot of us hot rod guys out here have Harleys too.
Maybe we could get Chevy366 to move out here too!
Take care in the City,
98 tigershark

No way , I thought you typed that corny Hick style real well , shows . :)
We are looking to move , might just do that , then you would be my Neighbor and Buddy right ? :rockon:
I think Greg doesn't realize that most people on here tune with EQ and not AFR , I know I have for a long time now , much easier , so Lambda is not that different .
What is strange is we have E85 cars and trucks in Texas , but no E85 stations in the area .
E10 is it worth the time and trouble ?
Or is GM close enough ?
And does B3601 make a quantifiable difference ? :anitoof:

[98 tigershark]

I had changed to the 14.07 AFR in B3601 a while back. I tried I have tried LAMBDA and EQ.. I am not use to LAMDA so I have to give it time to be fair.
The change to 14.07 made a very big difference and my car is happy!! Would love to have you for a neighbor!!! I am a redneck and proud of it!!
I really could hunt from my deck, no kidding. This morning we had dear and turkeys on the property. I have been all over and the NW country is a great place to live. It has a liberal label because for the most part we try to leave people alone and if they are weird ,oh well, I dont want the Gov. telling me how to live. Not to many tuners out here. I get allot of snow most years.
My son has 80 kids in his whole senior class. We are about 70 miles from the big city, not to bad. I really did raise cows, horses and sometimes pigs.
That was no act, sorry if it offended you as I really like Jeff Foxworthy and was really poking fun at myself. If you ever need help finding a place out here give me PM and I will forward you my info!!
We do have a few places in portland that sell E85 but none around here that are suppose too, even though I seem to have received some.
Did you look at the attachment?
Thanx,
98 tigershark:welcome:


No way , I thought you typed that corny Hick style real well , shows . :)
We are looking to move , might just do that , then you would be my Neighbor and Buddy right ? :rockon:
I think Greg doesn't realize that most people on here tune with EQ and not AFR , I know I have for a long time now , much easier , so Lambda is not that different .
What is strange is we have E85 cars and trucks in Texas , but no E85 stations in the area .
E10 is it worth the time and trouble ?
Or is GM close enough ?
And does B3601 make a quantifiable difference ? :anitoof:

[98 tigershark]

Hey all,
I have switched to lambda so I could learn more about tuning in general.
I seems a little backwards. So I have a problem that is a little different.
Mt car does not like to idle at stoich (14.047 for my stoich now), never did. My motor likes to Idle 13.97 AFR. It is not the fuel this time either as the motor is much happier now over all adjusting the needed AFR tables. But how do I convert the open loop to Lambda with this AFR up to operating temp and then to idle. It is not stoich but the motor likes it, This is not uncommon I am told for a built motor. So how do you convert AFR to LAMBDA accurately here. PE is now fine. I do not have my PC in front of me so I am sorry if I have said something wrong but I think you get the idea. Any ideas?
98 tigershark

[gmh308]

Hey all,
I have switched to lambda so I could learn more about tuning in general.
I seems a little backwards. So I have a problem that is a little different.
Mt car does not like to idle at stoich (14.047 for my stoich now), never did. My motor likes to Idle 13.97 AFR. It is not the fuel this time either as the motor is much happier now over all adjusting the needed AFR tables. But how do I convert the open loop to Lambda with this AFR up to operating temp and then to idle. It is not stoich but the motor likes it, This is not uncommon I am told for a built motor. So how do you convert AFR to LAMBDA accurately here. PE is now fine. I do not have my PC in front of me so I am sorry if I have said something wrong but I think you get the idea. Any ideas?
98 tigershark

If your stoich afr is 14.05, then idling at 13.97 would be 13.97/14.05 = 0.994 lambda. Which is within 1% so very close.

[SSpdDmon]

Hey all,
I have switched to lambda so I could learn more about tuning in general.
I seems a little backwards. So I have a problem that is a little different.
Mt car does not like to idle at stoich (14.047 for my stoich now), never did. My motor likes to Idle 13.97 AFR. It is not the fuel this time either as the motor is much happier now over all adjusting the needed AFR tables. But how do I convert the open loop to Lambda with this AFR up to operating temp and then to idle. It is not stoich but the motor likes it, This is not uncommon I am told for a built motor. So how do you convert AFR to LAMBDA accurately here. PE is now fine. I do not have my PC in front of me so I am sorry if I have said something wrong but I think you get the idea. Any ideas?
98 tigershark
The whole idea of going with lambda or EQ is to get away from AFR. The only time you need to know AFR is when you are deciding what to put in your tank. If it's E10, then you set B3601 accordingly. Once you do that and program your WB per my suggestions on the previous pages, you work with EQ or lambda from that point forward. You're done with AFR. Everything else in the tune and your logs should be EQ or Lambda from that point forward. If you need to....make a custom commanded EQ or Lambda pid. Then, you take the value that you have set in B3601 and either say WBO2/B3601=lambda or B3601/WBO2=EQ. That way you can work with EQ or lambda in the logs.

[98 tigershark]

Yes that does answer the question very well and it is appreciated very much.
Thanks again, I owe you guys.
98 tigershark

[SOMhaveit]

I've read this in its entirety and I have a headache.

So, I now know we have E10 in my area.

That means when my analogue wideband says 14.6 AFR, it really isn't 14.6, but is actually 14.1, which is what I want. So, if I'm running SDOL, and I'm commanding 14.6 and getting 14.6, which is what I need. And if I am commanding 12.8 AFR @ WOT, and my wideband indicates I am at 12.8 AFR, am I actually getting 12.36 AFR?

If that's how it's working, it's easier for me to keep doing what I've been doing?:help2:

[mr.prick]

No, it means that you need to change {B3601} to match the fuel you are using.
If you fill up w/E10 you need to change the value of EQ1 to 14.13AFR.
Changing {B3601} will change all fuel/AFR based tables.
Whatever your WBO2 is showing is (should be) what AFR actually is,
you need to richen the AFR in the tune.

[SOMhaveit]

OK, help me out please.

Even though I set all of my tables with B3601 at 14.63 and tuned the VE table while the car was running on E10, now I should set B3601 to 14.13?

My logged AFR and the AFR on the dyno mirrored each oher pretty well. Does the gas analyzer on the dyno misinterpret AFR with E10?

Isn't everyone saying that the wideband sees lambda and reports that as 14.63 whether you are running unmixed fuel or E10, or am I misinterpreting the posts in this thread and some other things I've read?

I thought G Banish said if you are running E10, when the wideband says the AFR is 14.62 i's actually 14.1x.

I guess I'm confused, not that that would be so unusual.

[mr.prick]

If your WBO2 is working/configured properly then
whatever it shows, that is what AFR actually is regardless of fuel type. :)
Filling up with E10 does not mean the WBO2 will be off.

If you are tuning with 14.63AFR you are a little lean for E10.
You set EQ1 {B3601} to the fuel type
(there is a spreadsheet in this thread somewhere)
and tune from there.

[Mr. P.]

Lemme take a stab at it - Greg Banish is right:

An O2 sensor only reports the amount of oxygen present in the exhaust stream - NOT the amount of 'unburnt fuel' or 'observed AFR' or anything else like that. in other words, the ONLY thing the O2 sensor can tell you is percentages, or "you're 2% lean" or "you're 5% rich" or "you're perfectly stoich". YOU have to take that percentage reported by the WBO2 sensor and do the math yourself based on the fuel you have put in the tank, like so:

Pretend example - If the WBO2 voltage is reporting that it's 3.5% LEAN, then the ACTUAL AFR is either:

a) 1.035 * 14.63 = 15.14 (in the case of pure pump gasoline fuel);
b) 1.035 * 17.2 = 17.80 (in the case of LNG natural fuel);
c) 1.035 * 15.5 = 16.04 (in the case of LPG propane fuel);
d) 1.035 * 9.0 = 9.315 (in the case of E100 ethanol fuel);
e) 1.035 * 14.6 = 15.11 (in the case of diesel fuel);
f) 1.035 * 14.1 = 14.50 (in the case of E10 pump gas fuel);
g) 1.035 * 10.0 = 10.35 (in the case of E85 fuel);
h) 1.035 * 13.8 = 14.28 (in the case of Sunoco GT-Plus 112-unleaded fuel);
i) 1.035 * 15.0 = 15.53 (in the case of VP 110 race fuel);
...
and the list goes on depending on the fuel you are burning. In each of these cases a cheap dash gauge will report "15.1" because the gauge assumes you are running pump gas with a stochiometric ratio of 14.63:1 because the gauge was hard programmed with that value. Likewise the PCM is seeing the same voltage from the O2 sensors but rather than assuming it goes and does a lookup of {B3601} and uses that value in all it's math; the issue is, if {B3601} doesn't match the correct value for the fuel actually being burned then the PCM is unknowingly fueling the motor incorrectly. In the usual case where {B3601} is 14.63:1 but you are burning E10 (14.1) then the PCM will unknowingly be fueling the engine about 5% lean; this will cause terrible economy but not hurt anything... UNTIL you go WOT, or worse yet WOT + boost!

Becuase of all the variance in fuels nowadays it is important to (1) set {B3601} correctly, and (2) stop thinking in terms of "AFR" in your VE tuning but instead use percentages (lambda or EQ ratio) - it's mentally similar to changing to the metric system, but in the end after you get your mind around the different units it's SOOO much easier.

Mr. P.

[joecar]

An O2 sensor only reports the amount of oxygen present in the exhaust stream - NOT the amount of 'unburnt fuel' or 'observed AFR'What Mr. P. said... this is the key.



Pretend example - If the WBO2 voltage is reporting that it's 3.5% rich, then the ACTUAL AFR is either:

a) 1.035 * 14.63 = 15.14 (in the case of pure pump gasoline fuel);
b) 1.035 * 17.2 = 17.80 (in the case of LNG natural fuel);
c) 1.035 * 15.5 = 16.04 (in the case of LPG propane fuel);
d) 1.035 * 9.0 = 9.315 (in the case of E100 ethanol fuel);
e) 1.035 * 14.6 = 15.11 (in the case of diesel fuel);
f) 1.035 * 14.1 = 14.50 (in the case of E10 pump gas fuel);
g) 1.035 * 10.0 = 10.35 (in the case of E85 fuel);
h) 1.035 * 13.8 = 14.28 (in the case of Sunoco GT-Plus 112-unleaded fuel);
i) 1.035 * 15.0 = 15.53 (in the case of VP 110 race fuel);
...
Did you mean to divide by 1.035 rather than to multiply by 1.035...?
i.e. row a) would be 14.63 / 1.035 = 14.13...

1.035 is Equivalence Ratio... i.e. EQR or simply EQ... (which equals 1/Lambda)... as various people have observed, it seems that EQ is what the PCM uses internally (i.e. for determining commanded EQ from all the lookup/modifier tables...) and applies B3601 to the "calculation" only at the very last moment prior to calculating injector on time... GM even provided the pid GM.EQIVRATIO (commanded EQ).

I have learned to think in terms of EQ, and after doing it for a while it really does come naturally... there's no going back.

[SOMhaveit]

I get it at this point. What has happened in my case is that during the auto VE process, I was unknowingly running E10 and made my VE table adjustments based on the E10, so my AFR is pretty good in my SDOL tune. I don't use the NB o2s or the STFT/LTFT.

I understand that the correct thing would be to put the correct value in B3601 and tune from there, and I guess I'll do it when I get a chance.

Thanks guys.

[Mr. P.]

...Did you mean to divide by 1.035 rather than to multiply by 1.035...?
Almost - I was thinking 'lean' but typed the word 'rich' instead :banghead: Sorry for the rookie move on my part.

Mr. P. :)

[joecar]

No worries... you should see some of my typos...:doh2:

If you meant 'lean', then 1.035 is Lambda instead of EQ in my post above.

[whackem04]

i changed my afr to 14.22 and posted a log. Would love input on it.
89 oct in the tank

[CalEditor]

Compare these 2 .bin files.
I need to check on the current reading of the wide-band on the Non Flex/Fuel with the stoich set at 14.17. I think he said it is 14.5
6632

6633

[98 tigershark]

I still keep running into E85 in gas stations out here. 4 now have done that to me and who know who else. In the sticks we have to get fuel were we can. You really have to be careful as E85 is only 2/3 the price to stations so in hard times they seem to get the less expensive stuff and charge you for normal gasoline. Your car will run cruddy and could even cost some repair bill and possible damage with that fuel so watch out for your motor.
I am getting really cold weather here and the vette is parked for the winter, How about everyone else in Spokane, or in the rest of the world?
Cheers,:->
98 Tigershark


Compare these 2 .bin files.
I need to check on the current reading of the wide-band on the Non Flex/Fuel with the stoich set at 14.17. I think he said it is 14.5
6632

6633

[ScarabEpic22]

Speaking from experience, Spokane is frigid right now. It says 26F out, the feel with the humidity and slight breeze is around 20-21F. Supposed to be down around 8F next week for a night or 2.

[CalEditor]

I am in Rock Hill SC. Nice down here. I need to make a trip back up to the frozen tundra soon.
Been tuning a Mazda Pickup with a Turbo Northstar in the rear and it runs on an LS1 PCM.

[DrkPhx]

FWIW - I wouldn't change stoich on a LS1 PCM based on supposed E10 ethanol content because the mixture can vary from gas station to gas station and even brand to brand. Here in MN, all gas is ethanol based (with a few rare exceptions), so it's a fact of life. Some of the newer stations have pretty good in-ground ethanol sensing equipment that allows them to monitor the content of each tank, but some don't. Most of the dealers also have ethanol content testing equipment to check fuel content when vehicles come in for warranty work for related repair. You would be surprised how much variance there is even from one station.

I've done a few test tunes with different stoich and fuel combos and always come back to the factory stoich and E10 93 octane for my TA for the best overall results. My .02

[CalEditor]

FWIW - I wouldn't change stoich on a LS1 PCM based on supposed E10 ethanol content because the mixture can vary from gas station to gas station and even brand to brand. Here in MN, all gas is ethanol based (with a few rare exceptions), so it's a fact of life. Some of the newer stations have pretty good in-ground ethanol sensing equipment that allows them to monitor the content of each tank, but some don't. Most of the dealers also have ethanol content testing equipment to check fuel content when vehicles come in for warranty work for related repair. You would be surprised how much variance there is even from one station.

I've done a few test tunes with different stoich and fuel combos and always come back to the factory stoich and E10 93 octane for my TA for the best overall results. My .02

That is way off in my opinion!

look at the 2 bin file and tell me what a wide-band would read on the flex fuel truck with E10 fuel

[dc_justin]

FWIW - I wouldn't change stoich on a LS1 PCM based on supposed E10 ethanol content because the mixture can vary from gas station to gas station and even brand to brand. Here in MN, all gas is ethanol based (with a few rare exceptions), so it's a fact of life. Some of the newer stations have pretty good in-ground ethanol sensing equipment that allows them to monitor the content of each tank, but some don't. Most of the dealers also have ethanol content testing equipment to check fuel content when vehicles come in for warranty work for related repair. You would be surprised how much variance there is even from one station.

I've done a few test tunes with different stoich and fuel combos and always come back to the factory stoich and E10 93 octane for my TA for the best overall results. My .02

The constant being that there is always SOME ethanol, with an "ideal" ratio of E10, it would make more sense to set the tune to the correct E10 stoich ratio and let trimming take care of the 2-3% swings either way. The alternative has fuel trims consistently 4-7% higher than they would be based on airflow calculation inaccuracies alone.

[DrkPhx]

The constant being that there is always SOME ethanol, with an "ideal" ratio of E10, it would make more sense to set the tune to the correct E10 stoich ratio and let trimming take care of the 2-3% swings either way. The alternative has fuel trims consistently 4-7% higher than they would be based on airflow calculation inaccuracies alone.

That certainly makes sense and seems like the logical thing to do. However, my car does not like to idle at anything richer than 14.6 (optimum is 14.8-15.2) according to my WB. The same holds true for some part throttle driving condtions as well. Certainly not at 14.0, otherwise it would choke on itself and die at idle and chug at low speed driving. This is CL with a MAF (no flames please).

[CalEditor]

That certainly makes sense and seems like the logical thing to do. However, my car does not like to idle at anything richer than 14.6 (optimum is 14.8-15.2) according to my WB. The same holds true for some part throttle driving condtions as well. Certainly not at 14.0, otherwise it would choke on itself and die at idle and chug at low speed driving. This is CL with a MAF (no flames please).

Have you logged a wide-band on a flex fuel truck?

[CalEditor]

Has anyone logged a Wide-Band on a Flex Fuel?
Has anyone looked at the spark tables on a Flex Fuel?
Has anyone looked at the spark tables on a lean cruise?

[DrkPhx]

Have you logged a wide-band on a flex fuel truck?

No. I don't own a flex fuel truck. My points are specific to a LS1 PCM that does not have those enhanced capabilities to sense ethanol content and adjust accordingly. We're all here to learn, so please shed some light on the subject.

[CalEditor]

No. I don't own a flex fuel truck. My points are specific to a LS1 PCM that does not have those enhanced capabilities to sense ethanol content and adjust accordingly. We're all here to learn, so please shed some light on the subject.

Download the 2 bin files from 2005 5.3L Trucks with the same OSID's that I posted.
Compare the 2 Calibrations. One would use the Ethanol Sensor and the other doesn't.
Them tell me what the Wide-Band reads at idle or cruise with E10 on the Flex Fuel

[gmh308]

Has anyone logged a Wide-Band on a Flex Fuel?
Has anyone looked at the spark tables on a Flex Fuel?
Has anyone looked at the spark tables on a lean cruise?

Yes. :)

[CalEditor]

Yes. :)

What did you find to be the Wide-Band Reading on a Stock Calibration?

[gmh308]

What did you find to be the Wide-Band Reading on a Stock Calibration?

Lambda = 1.00.

[CalEditor]

Lambda = 1.00.
Well how does that work?
Are you saying E0 = 1.00 Lambda and E10 also = 1.00 Lambda :confused:

So the Scan Tool (Tech II in my case) will display 14.7 as the target AFR and the wide-band will read 1.00 Lambda on E0.
Then with E10 the Scan Tool will display 14.1 target AFR and the wide-band will read 1.00 Lambda? :sly:

I understand that 1.00 Lambda for E10 is 14.1 AFR. Hmm did I state that correctly

[mr.prick]

It probably will. :hihi:

The WBO2 sees Lambda and if the AFR settings are gas you will see 14.7 or whatever Stoich is for gas on your WBO2 regardless to what is in the tank.
This is why you should change the fuel setting for the fuel you are using or
use Lambda to avoid confusion.

People with WBO2's that cannot display low AFR can use normal gas settings/display
with Ethanol because "Lambda is Lambda regardless of fuel."

This thread is about OS' with a static stoich AFR thus the reason to change {B3601}.
If you don't change this and use Ethanol the PCM will have incorrect VE/MAF values.

[gmh308]

Well how does that work?
Are you saying E0 = 1.00 Lambda and E10 also = 1.00 Lambda :confused:

So the Scan Tool (Tech II in my case) will display 14.7 as the target AFR and the wide-band will read 1.00 Lambda on E0.
Then with E10 the Scan Tool will display 14.1 target AFR and the wide-band will read 1.00 Lambda? :sly:

I understand that 1.00 Lambda for E10 is 14.1 AFR. Hmm did I state that correctly

Yes in closed loop whether E0 or E100, lambda will = 1.

AFR will change from as you mentioned 14.7 at E0, 14.1 at E10, 9.8 at E85.

Depends which PID you are checking with the Tech II. The EQ Ratio will read 1 when warmed up in both open (mostly...if that is what OL tables are set to for warm run) and closed loop.

If it is a Flex Fuel engine, then the fuel composition % PID will read the % ethanol it either calculates, or is told by the fuel comp sensor.

With that % ethanol, the ECM will then base its open loop + PE fueling and spark on the ethanol look up tables. And set base Inj PW from the AFR/ethanol % table B3671 (E38/E67). And if all the planets line up, WB lambda = 1, and LTFT's = 0.

Maybe techII has a PID that tells where the ECM is on the B3671 table? That would give you the AFR that the ECM is basing all fuel flow calcs on. Though no doubt depends on which OS you are on.

:)

[mr.prick]

GM.E85PCT :nixweiss:

[CalEditor]

Stock Calibrations: Flex vs Non Flex
http://i224.photobucket.com/albums/dd25/AJxtcman/PCM%20Stuff/Tables/Flex.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/PCM%20Stuff/Tables/NonFlex.jpg

The Stock O2 sensors will switch at about 450 mv and the fuel trims will be close to 0% on both factory calibrations and on the Flex Fuel across the chart.

A add on Wide-Band will display 1.00 Lambda and 14.7 also. Now lambda is not 14.7 Correct?

If I understand this correctly Lambda = AFR/AFR Stoich (Either from the chart or B3601)

A display of 1.00 on a Wide-Band will = the AFR Stoich, but the display on the add on meter of 14.7 doesn't mean 14.7 Correct?

Basically the Wide-Band Gauge is formulated for E0 or 14.7 = 1.00 Lambda and the gauge will always display 14.7 @ 1.00 Lambda even if the AFR is truly 14.1

[mr.prick]

@ Lambda1 the WBO2 will translate AFR to what it is set to for L1.
If L1 setting=14.7 then you will see 14.7 @ stoich which will actually be 14.1
Lambda will eliminate confusion without having to change the AFR setting.
You will also want commanded AFR to match the fuel you are using. {B3601}

Some WBO2's don't have a Lambda to AFR scale :bad:
so you will need to do the conversion yourself if
you want AFR to match fuel type.

Stoich AFR*Lambda=AFR
(someone correct me if I am wrong) :hihi:

[DrkPhx]

Yes in closed loop whether E0 or E100, lambda will = 1.

AFR will change from as you mentioned 14.7 at E0, 14.1 at E10, 9.8 at E85.

Wow. Am I understanding this correctly? You change B3601 to reflect lambda 1.0 instead of stoich and the PCM will calculate the fueling for different fuels based on that? I'm referring to a LS1 PCM. If I'm wrong, please clarify.

[mr.prick]

I could say "read the whole thread" but I won't and save you an hours time. :hihi:
{B3601} should be set to the AFR stoich point for the fuel you are using.
Changing it will also change all the fueling tables, as they are actually in EQ.
You see them in AFR because the software converts it from EQ to AFR based on
what {B3601} is.

If {B3601}=14.7AFR & PE=1.17EQ
then PE=12.56AFR

If you change {B3601} to 9.7AFR & leave PE@ 1.17EQ
then PE=8.29AFR

Moral of the story is:
{B3601}=stoich for the fuel type (static or flex fuel) &
if using AFR then make sure Lambda1=stoich for the fuel type so
the AFR conversion is right or use Lambda only.

[joecar]

Use/speak/think/breathe in terms of EQ...:cheers:

[DrkPhx]

Thanks for the cliff notes. I've actually read through the thread. For some reason I misinterpreted the quote above differently.

Like I previously mentioned, I did play around with changing stoich with mixed results. Fuel trims changed of course, but WOT PE remained exactly as previously commanded, though they are set as a AFR value and not lambda or EQ ratio.

I may revisit this again. Winter just officially kicked in here, so the conditions don't allow me to drive the car. Once again, thanks for the info.

[DrkPhx]

Use/speak/think/breathe in terms of EQ...:cheers:

LOL. I've tuned in lambda since day one, but switched to AFR a couple of months ago.:shock:

[CalEditor]

LOL. I've tuned in lambda since day one, but switched to AFR a couple of months ago.:shock:

I mainly tune off of Lambda and reverse it to EQ. I am not sure why I do it that way. Maybe toooooooooooo much time with Ford crap.

[CalEditor]

Maybe techII has a PID that tells where the ECM is on the B3671 table? That would give you the AFR that the ECM is basing all fuel flow calcs on. Though no doubt depends on which OS you are on.

:)

It has been a while, but I think the Tech II shows target AFR and % of E on flex fuel trucks.

[mr.prick]

Use/speak/think/breathe in terms of EQ...:cheers:

You should have locked this thread after this post, Joe. :grin:

Isn't EQ1 based on AFR? :laugh:

[joecar]

It seems to me the PCM generally does all of its work using EQR, and provides the AFR pid as a matter of courtesy/convenience/information.

[joecar]

If I lock this thread, then someone who may have some insight/revelation will not be able to post... :cheers:

If you really want me to lock it, I will... :gossip:

[dc_justin]

It seems to me the PCM generally does all of its work using EQR, and provides the AFR pid as a matter of courtesy/convenience/information.

AFR is still important for determining injector pulsewidth.

[mr.prick]

If I lock this thread, then someone who may have some insight/revelation will not be able to post... :cheers:

If you really want me to lock it, I will... :gossip:

:hihi:
It just seems like this thread is a mile long,
it has been informative tho. :blahblah:

[CalEditor]

Does anyone have a dbf for something like an 01 Vette and the later flex fuel trucks? Maybe even the dbf for the bin's I posted.

Joecar if I overstepped the boundaries delete this post.

[joecar]

I don't see any problem...

everyone has contributed their information/opinion in a civil manner... :cheers: ...thanks to all, this is a credit to EFILive forum members...:cheers:

discussion of differences is fine, everyone learns constructively...:rockon:


I think mr.prick (his real name) was simply joking about the thread being quite long...:hihi:...but that's ok.

[joecar]

I mainly tune off of Lambda and reverse it to EQ. I am not sure why I do it that way. Maybe toooooooooooo much time with Ford crap.
I use both EQR and Lambda from my LC-1 (in serial/digital format)... I like EQR better than AFR, it lets me think easier in relative terms (relative to stoich).

[joecar]

Does anyone have a dbf for something like an 01 Vette and the later flex fuel trucks? Maybe even the dbf for the bin's I posted.

Joecar if I overstepped the boundaries delete this post.I don't know who would have those...

The worse that could happen is a "no" response.

I don't see any boundaries being overstepped...

[joecar]

AFR is still important for determining injector pulsewidth.Oh, yes, I agree, that's how the PCM knows how to determine the actual fuelmass required.

The PCM does applies the modifiers in terms of EQR, and then at the last moment applies the stoich AFR to arrive at commanded AFR, which is required for calculating fuelmass, which then determines injector pulsewidth.

:)

[mr.prick]

I still think a FF OS for F/Ybody is a good idea. :devil_2:

[TunasTwins]

Hey guys, I posted this over at the tunercats forum monodax.com also.
I was under the impression that changing the values in the stoich AFRvs % alcohol in fuel table would make NO difference to my vehicle: 2005 4.8L Tahoe NON FLEX FUEL.
The table makes sense if you have an alcohol % sensor. Well I changed the values, up to 12.5% to 14.37 and EFI Live reports the desired AFR as 14.37 MY WOT also reports richer in EFI Live (14.37/1.165).
What I'm asking is why would EQ1=14.37 if I dont have a flex fuel vehicle?
EVERY pump here in Atlanta says may contain up to 10% ethanol so I'm assuming its in 90% of the pumps. Unfortunately this is my wifes truck so I dont have a bung for the WBO2. How much will my reading be skewed when the sensor is 6" in the tail pipe? What about taking out the rear 02 and installing there?
Well I hooked up the WB and have some results. Can someone point me in the right direction with the data I have?
I commanded open loop and reset fuel trims via EFI live scanner(love it!)
Commanding 14.68, at idle WB reads .98L 02's average .560's mv's
Commanding 14.37, at idle WB reads .96L 02's average .560's mv also.

I FINALLY understand (found) the closed loop airflow mode! NOW the rich/lean 02 volts table makes sense. My gut tells me to raise/richen the mv to .550 across the board. Also, it appears to me by changing the value in the % ethanol table, I'm telling the PCM that EQ1=14.37. Is this true?

[mr.prick]

Well I changed the values, up to 12.5% to 14.37 and EFI Live reports the desired AFR as 14.37 MY WOT also reports richer in EFI Live (14.37/1.165).
What I'm asking is why would EQ1=14.37 if I dont have a flex fuel vehicle?


Because you changed the value of AFR=EQ1 :)
All it does is put an AFR number to EQ.
Changing the Stoich AFR value will change other tables when viewed in AFR but
will not actually change the amount of fuel delivered.

This can be changed if you are using AFR instead of EQ/Lambda to tune and
your WBO2's is not able to change Stoich AFR=Lambda1 to match EQ1.
It's not necessary as long as EQ is properly set i.e. not lean during PE

FYI
If your WBO2 is not able to change the AFR value=Lambda1 then make a calc_pid.
6" from the end of the tailpipe is not a good place for a WBO2,
3' from the end is minimum.

[CalEditor]

Hey guys, I posted this over at the tunercats forum monodax.com also.
I was under the impression that changing the values in the stoich AFRvs % alcohol in fuel table would make NO difference to my vehicle: 2005 4.8L Tahoe NON FLEX FUEL.


Incorrect

[TunasTwins]

Incorrect
Please explain. The vehicle is NON flex fuel. Did I effectively change the EQ? Will this change the target AFR in closed loop also? Is changing the 02 switch point mandatory? TIA

[CalEditor]

Please explain. The vehicle is NON flex fuel. Did I effectively change the EQ? Will this change the target AFR in closed loop also? Is changing the 02 switch point mandatory? TIA

Did you post a question on another forum?

I will try to explain, but I need to pull an earlier flex cal first

[mr.prick]

What's more to explain?
You changed the AFR value of EQ1, this changes all Commanded AFR values.
(Stoich AFR/Commanded EQ)=Commanded AFR.

[bmax]

I have been following this also.

I am wondering, don't the narrow bands only read stoich.
Can the computer compensate for the difference in commanded?

When I get a chance I will do some logging to see the difference but it seems that even if you command 14.37 that the narrowbands will still look for 14.63.

Or I may be way off base. Do the switchpoints make that difference in the stoich points?

Any insight?

Brad

[mr.prick]

The NBO2's look for Stoich regardless of what AFR stoich is.

How Wideband (and narrowband) Sensors Work (http://www.innovatemotorsports.com/resources/news3.php)

[CalEditor]

I have been following this also.

I am wondering, don't the narrow bands only read stoich.

Brad

Correct You are changing Stoich switching AFR

This is figured from Air Mass and Fuel Mass

[CalEditor]

Can some one post the cal file for 1GNEC13Z82J242956 maybe I can later

[TunasTwins]

I have been following this also.

I am wondering, don't the narrow bands only read stoich. EQ1????
Can the computer compensate for the difference in commanded?

When I get a chance I will do some logging to see the difference but it seems that even if you command 14.37 that the narrowbands will still look for 14.63.

Or I may be way off base. Do the switchpoints make that difference in the stoich points?

Any insight?

Brad
This is basically what I'm trying to verify, along with the function of the %alcohol fuel AFR table (I'm using tunercats) on non flex fuel vehicles. I did post over at monodax but it usually takes a while for an answer. TIA

[TunasTwins]

sorry, didnt see the above post from MR. Prick. Guess I'll leave the 14.3 in the % alcohol table and set the 02 to switch around .525 and see what happens. Thanks guys.

[CalEditor]

This is basically what I'm trying to verify, along with the function of the %alcohol fuel AFR table (I'm using tunercats) on non flex fuel vehicles. I did post over at monodax but it usually takes a while for an answer. TIA

JWS6
pm me your email and I will get you more info.

[gmh308]

Please explain. The vehicle is NON flex fuel. Did I effectively change the EQ? Will this change the target AFR in closed loop also? Is changing the 02 switch point mandatory? TIA

The AFR table is simply a reference lookup for the ECM to determine fueling in relation to measured (MAF) or calculated (VE table) air mass flow.

i.e. in in open loop if MAF indicates 14.7 grams per sec of air and the AFR table at 0% alcohol is cal'd to 14.7 the injectors will delivery 1g/s of fuel.

If the table is set at 10:1 fueling will be 1.47 g/s.

It is a variable table to support flex fuel so that when the ECM knows via the fuel composition sensor or virtual fuel sensing system that the ethanol content for example is 50%, it can adjust the fuel flow accordingly to represent 11.8 parts of air to 1 of fuel by mass. In non flex fuel cals it simply sits at 0%. Pre flex fuel PCM's still had this calibration but it was a single number for gas.

NB O2 sensors are simply that: sensors. They measure and "report" oxygen content of the exhaust gas and are designed to be most responsive around stoich in terms of voltage output to oxygen content.

The ECM "drives" them by varying fueling around the crossover point/rich-lean threshold. There are 3 key points being the crossover point, the rich turn-around point and the lean turn-around point.

For example the crossover might be set at 500mv the lean turnaround 250mv and the rich turnaround 750mv. So the ECM adds fuel and the sensors see the voltage get to 750mv and then it pulls fuel until the sensors see 250mv and then it adds full again and graphed it looks similar to a sine wave. In an ideal world the crossover will represent stoich and the lean/rich turnaround points will be an equal distance from the crossover point but generally the calibrations will be adjusted slightly to cater for different O2 sensor response curves, engine characteristics and to achieve emissions targets, and maybe if thats all ok maybe some fuel savings can be fitted in as well by keeping them on the lean side a fraction longer than the rich side without screwing emissions.

:)

[CalEditor]

This is a 2002 5.3L Tahoe Flex Fuel calibration from a 512kb 0411 PCM in bin format

[SS Enforcer]

I tune my car in OLSD as I can do it quite well and car runs fine like that whenever I put any e10 in it i have noticed it run a bit lean. I mainly run the e10 just to keep the fuel system cleared of water, more of a maintainence thing really. I basically have 2 tunes setup for it so I can reflash it once the e10 is gone from the system.:)

The way I read it is we basically will use 5% more fuel running E10 over 98 ron fuel would that be a fair estimation?
If this is the case E10 needs to be more than 5% cheaper to attain any financial benefit from doing so. Given that E10 is usually only about 2-3 cpl cheaper than 91ron the average punter is getting ripped when they use E10.

cheers

[picnic_george]

Back from the dead... I just read this whole thing. My big question is...
On 91 my tune is really close, but I also run vp100 which has a stoich rating of something like 14.16. I've had 100 in my car for while and my LTFT are positive. I run CL MAF. I do tune in AFR(which I've been reading for years not to but I'm not changing lol).
I know what I want my AFR to be and it seems that is where it is. I set my car to run 12.3-12.5:1 on 91 which equals closer to 12.1-11.8:1 on 100 and that's where it runs.
So here is the big Q..
If I change B3601 to 14.16 what will I see happen? Will my fuel trims correct themselves closer to 0, when I scan WO2AFR(efilive) will it show me 12.5ish(even though my gauge will still show 12.1 unless I configure logworks) or will it do both?
And not that I have any plans in the near future to change over to e85(presumably exactly 85%), what would happen if I left everything the same and set B3601 to 9.85. Would it be in the ballpark?

Thanks
Kris

[Chalky]

Not sure why your LT keep adding fuel unless youa re seeing more ethanol or just better air/temps. All things being equal, your LT should get close to "0" by themselves. Your ST and LT trims adjustments are basically tweaking fuel delivery to keep your afr at stoich.

If you change B3601 to 14.16, 14.16 becomes your stoich. EFILive will then make changes to your OLCF table and your PE tables reflecting changes to B3601.

Much is dependent on what your currently have B3601 currently set at using your 91 fuel. If your B3601 is set to say, 14.63 and your change B3601 to 14.16, your PE table will change as well. I will assume your current B3601 is 14.63 and your PE table is flatlined at 12.3. If you change B3601 to 14.16, your PE table will be revised to approx 11.7:1 from 12.3:1. 11.7:1 is rich for even e10.

Try it. Create a dummy tune file of a current file. Change B3601 to 14.16. Save it. Open file back up and look at look at PE table. You will have new values.

My suggestion, find out what ethanol content is in your area. I bought a test kit used by airplane owners. I get mine from EAA in Oshkosh, WI. In SE WI, our E10 is really E5 for the summer blend.

Not sure about all WB's as far as readings. I believe Innovative LC1/etc c an be programmed to reflect revised stoich.

As far as E85, your could adjust B3601 to reflect stoich for E85 9.85. You would be in the ballpark. Question would be, are injectors and fuel system able to meet demand?

[picnic_george]

We have e10 oct 31 til jan 31??? here. It's considerably less during the other months. So my fuel trims being positive have nothing to do with running a fuel that commands more fuel to reach stoichiometry?
As far as air temps go, I live in the high desert. It can be 90 or snowing on the same day.

[Chalky]

Your LTFT should get back to close to "0" all things being equal. The problem is what could cause the engine to want to add fuel. Cooler temps, lower humidity, slightly different blends of ethanol, whatever. Have you tried resetting LTFT and see what happens?

If you were to start out in the morning with cool temps and a nice dense air charge, I could see the 02's commanding more fuel. If you continued driving and the temps went from say 30* to 90* and humidity jumped, your 02's would normally start pulling fuel to lean car out to maintain stoich. There are a number of influences to ltft adjustments than just fuel type.

As far as fuels, e10 will cause your 02s to add fuel to return car to stoich of 14.63 or whatever your B3601 is set at. Over time, your LTFTs will make adjustments to work with the e10 up to a point. While e10 will cause your 02's to command more fuel for a period of time, it should balance out eventually. They will never be "0" though.

Try this, assuming B3601 is currently B3601, change this tables to 14.10, load the file to your ecm. Start up scantool and log stft and ltft. Chances are very good, stft/ltft will pull fuel.

lastly, just because your pumps show e10 stickers, the actual fuel may in fact , be considerable less than 10% ethanol.

[picnic_george]

Ok so I reset my fuel trims and immediately they went positive and stayed there. Do you presume I just need to retune the car?
On the flip side I set b3601 to 14.17 and my commanded matched my actual afr idle average and in pe. I guess that's good lol. I need to tune my car at sea level I think because I'm sure if they are positive here at 4500ft they'll be way positive there which probably isn't a good thing. Unless I'm thinking backwards and positive fuel trim is pulling fuel not adding it.

[Chalky]

Have you changed intake systems or had your intake apart? You may have a persistent air leak. ?Can't believe a tune would help..

Any mods? Can you attach a log from scantool showing stft and ltft? Include a copy of the tune as well.

Positive trims mean fuel being added. FWIW, Not sure how big a positive reading you are getting but a couple of percentage points isn't a big deal.
.

[picnic_george]

I'll post my tune and log when I get home. I just logged a 10 min drive to my friends house. Seems to be about +10. I don't think there is a vacuum leak the maf is reading 10gs/sec which it has always seen at idle. I think my fuel trims may have always be positive though.

[picnic_george]

But here is what it is right now. I just added a few degrees of timing to see if I could pick some hp on the butt dyno. First log is driving to a friends house the other one was a quick little blip to check my afrs. I'm not real happy with the tune on this car anyways so I'm going to redo it. I think I may know why my fuel trims are off.
This car is a 98 trans am(98 pcm) m6 forged 347 ls6, 228/232 112 11-11.5:1 cr 100 octane pump gas.

[Chalky]

Quick solution: With a cam in that range, your 02's will pretty much think the car is always lean due to 02 sensors seeing unburnt fuel. That is the reason you are seeing positive fuel trims. I would guess that the car acts and reads quite lean at idle.

I ran a 224/228 on a 114 and had same issue.

After a quick look:

MAF table is rough. MAF table is normally a smooth transition from low to high.
VE Tables: Again, really rough with spikes. I would expect a more rounded graph in the 4800 rpm range. Also seems like lower rpm, idle range is very lean.

IFR table: Not sure what injectors you are running but the IFR table values have almost doubled over stock.

What type of injectors are you using?
What intake manifold are you using, LS1, LS6, FAST?
Stock TB?




Spark tables: Changes made to date are pretty much ineffective.

I ran a very similar setup with 11.5:1 CR.

[picnic_george]

Crazy elevation (7200-0ft) and weather changes. I'm keeping the o2 sensors, I need all the correction I can get lol

[CalEditor]

I posted some information that wasn't so good.
Set you stoich to 14.0 if you have E10

I would think if you have E10 then you will be on the High Octane Table

http://i1106.photobucket.com/albums/h361/PCMCalibrator/Tuning%20Tables/EFILive/04%20E85/33.jpg

http://i1106.photobucket.com/albums/h361/PCMCalibrator/Tuning%20Tables/EFILive/04%20E85/HighOctane.jpg

http://i1106.photobucket.com/albums/h361/PCMCalibrator/Tuning%20Tables/EFILive/04%20E85/E85Adder.jpg


12051

[picnic_george]

42lb injectors. I've changed the spark tables a few times. I was running a stock ls6 table but decided I needed more so I used the 98 table and went to 28°. The ve table is smoother now. I went off and retuned the car and it didn't help anything. The stupid thing was telling me it was super close throughout the range in olsd. Whatever I guess :shrug: still doesn't tell me why my fuel trims are out of whack at idle. Probably some setting I missed. I don't remember what the maf looked like I'm check it again, I didn't get that far yet. I don't drive the car often. It's got 1600 miles on it in the last 2 years 1200-1300 of it was breaking in motor, transmission, clutch, and rear end lol.
I'll get back to it later and get it more dialed in. Ls6 intake..

[mr.prick]

2 Questions:

1. Are you using {AFR}/{GM.AFR} as BEN factor? (analog or serial)

2. What are the injector offset settings?

[Chalky]

I guess I am confused. Your tune you attached has a rough ve table but you said it is smoother now.

As far as your idle issue, I explained what was happening. With a big cam, you run some overlap, the 02's see the unburnt oxygen and assume car is lean and the 02s then add fuel.

Just curious but are injectors 42# @ 3 bar or 4 bar?

[picnic_george]

2 Questions:

1. Are you using {AFR}/{GM.AFR} as BEN factor? (analog or serial)

2. What are the injector offset settings?1. I'm pretty sure thats what it is. 2. IDK I did that 2 years ago


I guess I am confused. Your tune you attached has a rough ve table but you said it is smoother now.

As far as your idle issue, I explained what was happening. With a big cam, you run some overlap, the 02's see the unburnt oxygen and assume car is lean and the 02s then add fuel.

Just curious but are injectors 42# @ 3 bar or 4 bar?I've spent the last 2 days dicking with my tune. Smoothing a tune is one of the easier things I've done. They are standard bosch 42lb injectors. Those are rated 43.5 psi.

That cam is tiny, I just always read about negative fuel trims with more cam and maybe no one is referring to ide. I guess I should stop worrying about it :shrug:

I think the reason my VE table was so close is for some reason my car has to be correcting fueling. I noticed there are STFT while in OLSD. Why would that happen, LTFT is disabled and o2 are not supposed to go to closed loop before 252 degrees, but i remember reading here sometime ago that they may still be doing something.

[mr.prick]

It looks like {B4001} was increased but all the other tables in the injectors folder are stock.
This maybe the issue

If you change {B3601} and use AFR for BEN there can be another problem too.

[Chalky]

From the looks of it, you are using IFR values for 3 bar 42# injectors. With GM being 58#, 4 bar, you need to bump up your IFR tables.

As far as STFT/LTFT, if you are in OL, trims are not being influenced by 02's. Could your MAF still be functioning and not in SD? MAF or 02's functioning pretty much make ve tuning a waste of time.

Personally, I liked my cam 224/228-114 with xer lobes. I would have gone to 228/232 with afr 205 heads I had but I worried about PTV clearance. I just thought that size cam was about perfect for a street motor of this size. JMO

[slows10]

Must be in semi open loop if stft are changing O2 voltage?

[picnic_george]

It looks like {B4001} was increased but all the other tables in the injectors folder are stock.
This maybe the issueWHat else would I be changing? I just used the injector spread sheet and the car started right up.

If you change {B3601} and use AFR for BEN there can be another problem too.I just recently changed that seeing what would happen. I don't think I'll be leaving it there.


From the looks of it, you are using IFR values for 3 bar 42# injectors. With GM being 58#, 4 bar, you need to bump up your IFR tables.I'll recheck that but I'm positive I did it right.


As far as STFT/LTFT, if you are in OL, trims are not being influenced by 02's. Could your MAF still be functioning and not in SD? MAF or 02's functioning pretty much make ve tuning a waste of time.The MAF is unplugged when I do it. I'm presuming the o2s are messing up the program.


Personally, I liked my cam 224/228-114 with xer lobes. I would have gone to 228/232 with afr 205 heads I had but I worried about PTV clearance. I just thought that size cam was about perfect for a street motor of this size. JMOIt seems to work well. I would have went bigger but my car weighs 3800lbs and has a whopping 347 cubic inches so I stayed there.



Must be in semi open loop if stft are changing O2 voltage?That's my assumption. I don't know any better. There has to be a reason, I made some tweaks to the ve table and every cell I hit was within 1% and I know my original tune was not even close to that good. And even if it was, it would be off by more than that. Loggin o2 voltage won't tell me anything though, unplugging them is too much of a PITA.

[slows10]

To run total open loop I think B4206 has to be disabled. If it is enabled then o2 feedback will be used with the open loop table B3605. Also B3801 has to be disabled. B4205 set to max temp. Are you trying to just run open loop with no trims?

[picnic_george]

I'll check that, I hope that's the problem. Yes I want no fuel correction at all. It's been a while and my brain is toasted lol Thanks