trying to wrap my head around E10

[efizjb]

I'm trying to wrap my head around E10 and the long threads give me headaches as many times as I try to slow down and understand in simple terms


For sake of argument and calculations, can I refer to E10 stocih as 14.1 and regular fuel of 14.7 (I know there's decimals to carry out but for simplicity...) and an understanding of approx .6 diff...

Assuming stoich was set at 14.1 for ECM and LC-1 gauge was set at 14.7 (.6 difference) and for use of a AFR # say the gauge read 12.5 at WOT what would that 12.5 acutally be? would it be of more realistic of 13.1?

Now with that being said would both ECM and lC-1 set for 14.1 and gauge on a WOT run showing 12.5 would that be real, or do you still add .6 to LC-1 reading (some threads point that LC-1 is going to read actually no matter what, and this is what throws me...)

The whole E10 thing in reading the threads has me lost in what an LC-1 would read with E10, and what the LC-1 should be set at. I also understand that the point has been made to think and use EQ/lambda, not AFR, and I can learn to think that way, but if I can get the theory understood in AFR first, I can make that leap....:doh2:

[mr.prick]

It depends on how you are getting data from the LC-1. :sneaky:

For analog you take the programmed Lambda values and stoich AFR ({B3601} ect.) and make a new PID.
For serial you change the fuel type to custom (.1 precision) and match it to your stoich AFR {B3601}.

If this is for an Fbody w/V2 & serial LC-1 simply change {B3601} to what you want, log {GM.EQIVRATIO} & {EXT.WOEQR1}
Then a new BEN factor PID can be used ({GM.EQIVRATIO}/{EXT.WO2EQR1})

[WeathermanShawn]

efizib:

Try doing a log running both a Calculated Pid for 14.1 as stoich and also 14.7 as stoich.

Leave B3601 as is. Then compare each. You will see how the percentages work.

I think Joecar and Mr. Prick have the Calc Pids. Works easier with Serial Connection.

It is not hard to calculate your two examples, but I agree it gets confusing. For myself, utilizing the Calc Pids is a far easier way to understand it.

Are you Analog or Serial?

[efizjb]

Analog. The tutorials were for analog hook up, I didn't think I would ever be using serial...this is making a little more sense

[efizjb]

Mr Prick, i just realized you have a link in your signature!

[joecar]

...
Works easier with Serial Connection.
...
+1.

[joecar]

efizjb, do you have FSV1 or FSV2...?

[Gordy M]

You might test the percentage of alcohol in your gas locally to set the right AFR. A friend was using 14.07 and we found a 120ml graduated cylinder. Put 30 ml of distilled water and 90 ml of E10 gas and mixed. Ended with 37 ml of water/alcohol solution which yielded E7 gas. Another friend in Oregon did it and found his gas (41ml) is really E11. Then change your AFR accordingly.

[mr.prick]

:iamwithstupid:
Good idea.
Alcohol test tubes can be found on ebay. :secret:

Maybe the EQ BEN PID could be included in the next update. :angel_innocent:


#Units Low High Fmt Expression
#------------ ---------- ----------- -------- --------------------------------------------------------------
*CLC-00-007
factor 0.00 2.00 .2 "({GM.EQIVRATIO}/{EXT.WO2EQR1})"
# ================================================== ========
#Code PRN SLOT Units System Description
#--------------------- ----------- ---------------- --------------- --------------------
CALC.EQ_BEN F007 CLC-00-007 factor Fuel "EQ BEN"

[Chevy366]

Here are two tun files , one that I threw together , one has the tables from a L59 Flex fuel tune copied to it (I tried not to miss any differences in tables) and the other is just for comparison (can't open different OS tun for comparison , V8 soon) .
Notice how GM uses the VE (added 6.5 , 4000 rpm and up) , timing to compensate for E fuels and injector size and flow .
Gives us a perspective as to how GM looks at E fuel .

[efizjb]

Sorry guys, Joecar, I've been away a bit, I'm using V2

[WeathermanShawn]

efizib:

Refresh our memories as to what OS and PCM and type of tune you are using. Is this Flex Fuel or are you utilizing the LS1-type PCM?

Does your tune utilize Trims? And what is your WOT fueling set for?

Sorry for the additional inquiry. Sometimes it is best for all the readers following the thread to get a good summary.

Thanks.

[joecar]

If you have V2 then you should use the serial AFR/Lambda capability...

See post #3 here: showthread.php?9340-serial-port-cable-that-goes-to-v2 (http://forum.efilive.com/showthread.php?9340-serial-port-cable-that-goes-to-v2)

Also see post #8 here: showthread.php?14351-BBL-PIDs-V2&p=128785#post128785 (http://forum.efilive.com/showthread.php?14351-BBL-PIDs-V2&p=128785#post128785)

The serial AFR/Lambda gives better data which has immunity from analog voltage offsets and induced ignition noise.

[efizjb]

Thank you Joe!

Shawn, I'm just running a 2002 LS1 OS, CL nothing out of ordinary.

I guess I'll simplify my question from what I know and see if it clicks in my head.

When I last dyno'd the car last year not even thinking of E10 as being part of the equation, stoich was factory setting (14.63) and LC-1 also set for same stoich. My VE and PE #'s were pretty damn accurate for street tuning only. My PE was set for 12.9 and the whole pull was between 12.8 and 13.0 on both the dyno O2 and also the same on my LC-1.

Now what confuses me is the statement the LC-1 is going to read lambda no matter what the ECM is set at. I understand the LC-1 doesn't care what the setting the ECM is, that I get...

Now with all the aforemetioned, if I were to go in and ONLY change stoich in the ECM for E10, would the same dyno pull now read say 12.2-12.4 assuming .6 diff in stoich for sake of using a general # (not changing stoich in LC-1 software, I understand it won't be an exacty .6 due to percentages etc, just using as a general # for this example....)

If I can understand what this scenario would look like, I think I can digest this. I can then go to using lambda from there, I just gotta understand it in a language I know first lol
on my LC-1

[5.7ute]

Your wideband would still read the same as before in the scan tool, but the scanned commanded AFR pid (GM.AFR) will change.
This is due to the PCM doing all its commanded fuelling calculations in EQ ratio. Basically after it has calculated the commanded EQ ratio it divides stoich(B3601) by this amount to give it a value for the IPW calculation.

[efizjb]

Okay, making sense now, thanks Ute. Based on that, I take it I am probably in an unsafe WOT PE. I guess it makes sense to change the stoich for E10 and go at all of this again...

[WeathermanShawn]

Yea try that.

Your question intrigued me enough to do some experimenting myself. I have been logging differing B3601's, LTFT's and WOT Fueling. You will see your Trims adjust and WOT PE fuel needs to be tweaked by about 4%.

That tweaks the airmass calculation by a similar amount. A lot of it did not make sense until I tried it out..:)

[5.7ute]

You can get away with going from normal pump gas to e10 without any major concerns, as the fuel trims will add the necessary percentage to the airmass estimation. (As long as you stay away from WOT until the trims have had sufficient time to calculate the change)
However. if you went the other way & used pump gas on an e10 tune, since negative trims do not carry over into WOT you will be too rich under these conditions.
Personally, I classify the fuel as a piece of hardware, & calibrate the PCM to suit.

[WeathermanShawn]

Ultimately I found the IBPW1 to be nearly the same with an E10 Tune vs E0. The Trim function in closed-loop make it virtually identical in non-PE mode.

WOT say a 'richer' AFR (same EQ), but my airmass also decreased by about 3-4 %, again making the final IBPW1 nearly the same.

I get the concept, sometimes I wonder if it is really necessary on LS1? It is lot of work and seems 'circular' in the final results.

Anyway, the subject has been well-discussed. OP, let us know your results and if you make any conclusions.

Good luck.

[joecar]

Just remember this:
- Lambda is not specific to any particular fuel,
- AFR is specific to a fuel's stoichiometric AFR,

AFR = Lambda * stroichAFR

[WeathermanShawn]

efizjb:

If your VE/MAF/Trims are good, why not just change PE Fueling to an EQ of 1.20 or ~12.1 AFR. (Leave LC-1 as is).

Doesn't that accomplish the same thing? Closed-Loop will be lambda regardless, and changing B3601 to 14.13 will just give you more negative trims and get you to the same 'AFR' you need to be at with E10.

There may be up to a 4% airmass error, but if my logic is right you do not need to change your wideband settings or B3601 at all.

Guys & Gals is my logic correct?

Edit: What type of fuel were you using when you had the dyno? If it was E10 and your wideband was reading .875 Lambda, that would equate to a ~ 12.3 AFR. Your wideband may have been set for gasoline. If that is the Lambda where the dyno found the most power..then why change anything?

[5.7ute]

Increasing PE commanded fuelling will only cause an error as trims will be ADDED when going to E10 on a petrol calibration.

[WeathermanShawn]

Mick:

I think what has happened to a lot of Tuners in the U.S. is that they have calibrated a gasoline tune (14.63), but unknowingly the fuel type has been E7-E10 for quite a while.

So, probably the majority have already compensated for the fuel type in their airmass models. If you change B3601 to 14.13 your Trims will go more negative. The airmass has already been 'fudged'.

I am talking about tuners who already unwittingly had E10 in your tank but tuned for E0. Changing B3601 will require a corresponding change in the airmass models.

I would be willing to start a new thread and provide some sample logs, but I think people are either burned out on the topic or confused beyond belief!

[joecar]

...
but I think people are either burned out on the topic or confused beyond belief!This is what I think is happening... this and the AFR way of thinking.

The alcohol content test mentioned above is a great idea.

[5.7ute]

Mick:

I think what has happened to a lot of Tuners in the U.S. is that they have calibrated a gasoline tune (14.63), but unknowingly the fuel type has been E7-E10 for quite a while.

So, probably the majority have already compensated for the fuel type in their airmass models. If you change B3601 to 14.13 your Trims will go more negative. The airmass has already been 'fudged'.

I am talking about tuners who already unwittingly had E10 in your tank but tuned for E0. Changing B3601 will require a corresponding change in the airmass models.

I would be willing to start a new thread and provide some sample logs, but I think people are either burned out on the topic or confused beyond belief!

No worries. I forget sometimes that we are a bit behind when it comes to ethanol fuels. (especially where I am)

[WeathermanShawn]

No worries. I forget sometimes that we are a bit behind when it comes to ethanol fuels. (especially where I am)

No worries here. This stuff will have you doing brain contortions after a while.:grin:

I am going to get one of those test kits for Ethanol and see what my local station has as a fuel type.

OP, hope you have your questions answered.

Good luck..

[efizjb]

Glad I posted, I thought I may get a "hey there's threads on this subject", this generated a good discussion, I've got to reread and digest it, but this does simplify the subject.

Shawn, to answer your "edit" question, I think our state was already on E10 here at time of that dyno run. So to sum that up, my LC-1 and ECM stoich was left to factory settings, for gasoline(E10 not a thought in anyones mind). The LC-1 read 12.8 to 13.0 throughout pull. MY PE table was set to a flat line of 12.9 so I was suprised at how close I was from only messing with VE on the street prior. Based on this, is why I thought I should either set stoich at 14.13 or bump PE down to say 12.3 no thinking about ethanol...as LC-1 reads lambda anyway is why I didn't know if I should change it. You're saying fueling will be off about 4%, and others are saying trims will take care of it, but wouldn't that NOT be true for PE, but under normal CL VE operation not default PE settings?

Sorry if I'm confusing this more guys! I figure by answering Shawn more might be revealed for those of us still learing.

[WeathermanShawn]

I was wrong about PE. It will be affected.

Your situation is not that different from mine. Here is how I understand it.

1. If you know your Fuel Type (E10) set B3601 accordingly (14.124 AFR).
2. Best to just leave PE Modifier in either EQ or Lambda. Set PE to .85 Lamda or EQ 1.18 or whatever you determine is good E10 fueling.
3. Log and adjust Trims accordingly.
4. Use Calculated BEN to tune Commanded AFR vs Actual.

Thats my take...