Help on direction of Commanded AFR and E10

[Mikz86ta]

Ok so a while back I had changed my stock AFR (B3601) of 14.68 which I understand is GMs idea of stoich with std petro.
I changed it to 14.2_ at one time as recomended for E10.
Fuel here is UP TO 10% Eth. all grades.
I been reading more and decided to change to 14.12/14.13 range. And at lunch I felt reg driving, it seems ok. But on WOT run I did, it was a freaking pig.
I may already have an idea of why but wanted to ask.........Is the PE ratio need to be adjusted lighter in revelance to the higher commanded AFR? I assume since my AFR Commanded is changed to richer, then the additional fuel is being dumped in PE is higher now than before?
Like for lack of saying this exact, CAFR 14.6 + PE 1.8 = 12.6 (yes I know this isnt exaxct or close..just a newbie trying to explain/confirm my theory.
Then I have CAFR 14.12 + same PE 1.8 = 12.1. Thus when going into PE now its even fatter than before and bogging?

I am kinda old carb tuner guy and feels like the same when squirters are changed to too large and too much fuel is dumped in.


So...should I just go back to the safer 14.2_ AFR for E10 and leave PE same?
Or keep on track with 14.12 AFR and readjust the PE ratio lower?
Or do I need to log and add timing?

[joecar]

Look at PE in EQ units; the same PE EQ is suitable for E00 and E10.

Leave B3618 PE same, and set B3601 to 14.2.

[EagleMark]

What he said! I've been getting away from AFR all together, was easy to deal with Lambda instead. The PCM deals in EQ Ratio. 1.00 equals Stoich. Wideband deals in Lamda 1.00 equals Stoich. Narrow band O2 sensors run Stoich.

Only problem there is
EQ ratio is 1.15 = adding fuel.
Lambda reads .85 as richer, so inverse but not exactly.

Also wideband AFR of E10 at WOT is about 11.90 in my last log. But lamda is .85 where it should be. So differant fuel equals differant target AFR... but if you deal with Lambda it's always the same. Target .85 with gasoline or target .85 with E10, or...

It'll give you a headache as an old carb guy, I'm one, but have been EFI long time now. Just set B3601 to AFR then forget using AFR for anything... hurts at first but then you realise how easy it is and much more accurate.

[joecar]

EQ = 1/Lambda

so 0.85 lambda equals 1.176 EQ.

[joecar]

...

It'll give you a headache as an old carb guy, I'm one, but have been EFI long time now. Just set B3601 to AFR then forget using AFR for anything... hurts at first but then you realise how easy it is and much more accurate.+1

once the concept of EQ and Lambda is understood then it becomes very easy...

[Mikz86ta]

Ok I had set it to 14.32 on the ride home and it still felt bogged down.
IDK what else I could have messed with :(

I have a AEM wideband with gauge. I also have it wired to the V1 for logging. Just fyi

I will reset it tomorrow and see. Otherwise I need to do a log and find out whats going on.
I dont recall readjusting PE from when I did it months ago and it was fine until today. But reguardless it seems when I go into heavy throttle there is a bog..not like fall on its face...but rather the exh sounds loud still as I am heavy on the trottle but just not picking up speed

[joecar]

Are your MAF and VE tables correct...?

What does your PE table contain...?

Is your IFR table correct...?

[Mikz86ta]

Never messed with MAF and VE. Still never did the Auto-VE.
PR I had only 0 out the Delay B3608, 0 out the 3610 RPM Bypass and adjusted B3615/B3616 which is the TPS % for the PE to activate. Stock was 90% all the way down. I had reduced it to 90 70 60 40 in steps according to higher RPM. I was told to just make all them like 70 or 50.
The PE chnges have been done for about 8 months and this issue is a new one.

I may have accedently changed something with Torque Limiting and/or Abuse Mgmt sections. Tho I have a 4.3/5speed 2003, I was told there is no Tq Mgmt, no settings set for abuse mode and no settings for Trac Control....but those sections do show up. B6601 is Enabled from the factory stock tune. Most Trac Control section adjustments are 0 and some are filled in Stock Tune. I left all those alone anyways.

Anyways, I found one or two Tq Limiting section things I accedentally adjusted ( B6601 from enable-stock and changed to disable) (B1901 from 300 I changed to 350 apparetly)

[Mikz86ta]

Weird....for some reason under Engine Calibration, I have a new RED folder called Electronic Throttle. It does not show up under my Stock Tune File I loaded up to compare. I never seen the Red folder before. WTH? I didnt add it and I have only used this for MY truck.

[joecar]

Red folder: only shows up when PC/laptop is connected to V1 or V2...

the reason for this is to restrict access since those tables in the red folder can brick your PCM.

[joecar]

If VE and/or MAF are not corrected from the factory, you can count on the factory tune being rich.

[Mikz86ta]

Oh, must have been there when I had it plugged in the truck and left the scan tool / tune tools open when I unplugged the laptop from the V1.
I didnt mess with any of those settings. Prob gone after I reboot the laptop. Have not checked.
Thx

I must have done something with the Tq Mgmt, Traction or Abuse Mode. Cause at lunch today it seems to be fine now. And thats with 14.22 Comm AFR setting still.
I reflashed after I reset all the TqMgmt, Abuse, Trac settings to mirror stock.
As far as I know I have no Abuse (heard its only Autos), no Tq Mgmt (heard only autos) and my 2003 S/T 4.3/5M truck had no Trac Control. But obviously a setting change in EFILive can affect it

I will test again on way home and see how it feels.
I did do a log on way to lunch. A DMax 2500 Sierra tried me to while I was in logging :) Black smoke was behind me, so I was happy abt that :)

[Mikz86ta]

If VE and/or MAF are not corrected from the factory, you can count on the factory tune being rich.

Factoy settings for these are still in effect. I hear that abt GM also...it being rich stock. Im sure a VE and MAF tune will help me out.

FYI I have a K&N FIPK, 1.52 full rollers and headers/y-pipe/no cat/hooker maxflow/dumped as far as air in-out mods

[Mikz86ta]

Clear me up a bit on PE and EQ Ratio.
If my original Comanded AFR B3601 was 14.68, and my PE Modifier/RPM B3618 is 1.18 and 1.20, then my AFR in PE changes per that ratio. Its divided right. So respectively in PE my AFR should be 12.44 and 12.23.
If I changed my Commanded AFR B3601 to 14.22 as I did for the E10 , then my same PE Modifier/RPM B3618 will be effected...thus 12.05 and 11.85 respectively ??

So I have a richer PE mixture than before? And maybe too rich. So should I lower the EQ Ratio B3618 values to get back to the prior AFR in PE of 12.44/12.23? Or even maybe less? I hear the goal for rich at WOT is best power around 12.4-12.9 or so. That sound right?
Reading forum post, some google searches, the tuning book, etc for this direction of thought.

Thx in advance

[EagleMark]

Yeah but if your changing to 14.22 your running E10. Internet says it runs at 13.8 to 14.3. Mine runs 13.9. So you think 12.44 is to rich for PE/WOT but it's actually to lean for E10.

If you want to end the confusion deal with Lambda from the Wide Band and life will become less confusing...

Change commanded to 14.22 and watch serial WB run at close to 1.00 Lambda, watch it right now with commanded set to 14.68? Still close to 1.00 Lambda because the narrow band 02 sensors correct back to Stoich of fuel (LTFT will change), they don't care what fuel. Stoich is 1.00 and WB reads it as Lambda 1.00

If it wasn't for B3601 we would never have to think AFR again...

[joecar]

For NA you want PE at WOT to be about 1.175 (say 1.18) regardless of fuel (E00, E10, E15, E85)... like EagleMark said, work in lambda or EQ and forget about AFR.

[Mikz86ta]

Yeah but if your changing to 14.22 your running E10. Internet says it runs at 13.8 to 14.3. Mine runs 13.9. So you think 12.44 is to rich for PE/WOT but it's actually to lean for E10.

If you want to end the confusion deal with Lambda from the Wide Band and life will become less confusing...

Change commanded to 14.22 and watch serial WB run at close to 1.00 Lambda, watch it right now with commanded set to 14.68? Still close to 1.00 Lambda because the narrow band 02 sensors correct back to Stoich of fuel (LTFT will change), they don't care what fuel. Stoich is 1.00 and WB reads it as Lambda 1.00

If it wasn't for B3601 we would never have to think AFR again...

Thats true about E10 in PE needing to be richer as well. Thats why I inquired :) I knew I was missing some logical detail..lol
IIRC up to 4400RPM the EQ Ratio is 1.18 an steps to 1.20 after.
I notice sometimes when I am 'gettin it' heavy on the throttle pulls (WOT) at night, lights behind me reveal a puff of smoke which indicates to me very rich.

I do need to educate myself and rely on Lambda more as I read more and more about this stuff

[Mikz86ta]

For NA you want PE at WOT to be about 1.175 (say 1.18) regardless of fuel (E00, E10, E15, E85)... like EagleMark said, work in lambda or EQ and forget about AFR.

I am realizing that I need to educate myself in Lambda :)
Thx for the pdf Mark!

[DrkPhx]

Mikz86ta - As mentioned above; tuning WOT is easier using lambda especially when messing around with different fuel compositions. You can change the display value to lambda by going to Edit > Properties. Make the change, close and reopen the tune file so the change takes effect. If you're tuning to E10; you should actually test the fuel for ethanol percentage. You would be surprised at the variance between pumps and different stations (even the same station on different days). Gas stations are required to put up to 10% ethanol content in their fuel. I've seen variances between 3-5%. Personally, I would leave stoich at factory unless your PCM can adjust on the fly like some of the later models. Do you have a wideband installed to monitor AFR?

[Mikz86ta]

Any leads on Eth Test Kits? Kinda why I adjusted Comm AFR some place in the middle and not exactly for E10. I do have AEM Wideband gauge and its hardwired to my V1

I appreciate your input :) Thx

[DrkPhx]

I use a cheap pyrex test tube I bought from Summit. You add a little water, then fuel and shake it. Once it settles you can see the ethanol content. There are actual fuel composition testers; but they're more expensive.

[Mikz86ta]

Cool, I will have to look into that. Thanks!