Tuning for e85???

[roderick]

WOW skatin this one guy is a tard. If anyone doubts skatins advice use google and search.

Here you go skating

No. You are on track, for your eclipse.

We like to run a little rich on the LSJ. Most guys like 11.5 - 11.9. So that is pretty much on track with what your used to.

When I was doing my E85 research I found a Subie guy and EVO guy and they ran their E85 converted cars at 11.8-12 (gasoline) afr on their cars. Some guys would lean the car out to 12.2 - 12.5. Again those are afr numbers based of off gasoline calculations.

Instead of changing my stoich afr from 14.7 (gasoline) to 9.765 (E85) AND all my other fuel settings in my tune I left them to the gasoline settings. I also left my wideband to read gasoline afr. It is a very common practice for E85 converts.

When the wideband and your cars rear narrow band calculate afr it is based off of lambda. It then multiplies the lambda readings by the stoich fuel setting in the tune.

NCState said it best.

Quote:
Originally Posted by NCStateRedline View Post
It is the lambda converted to a gasoline stoichiometric readout, which coincidentally is the correct lambda for ethanol (just not reported that way).



so if you were running on gasoline at 12 AFR the lambda would be

λ=12/14.7(the stoichiometric ratio for gasoline)=.816

running ethanol at 7.968 (which zzp did) the lambda would be

λ=7.968/9.765 (the stoichiometric ratio for e85)=.816 (coincidentally the same lambda as running gas at 12)

The readout multiplies lambda by the stoichiometric AFR of the fuel burned to give the readout we're used to and because it was still set for gasoline, it multiplied it by 14.7 and got the 12
I am running a little rich to be safe. That is why my afr is where it is. I should be able to lean the car out for more power. But as I found (on pump gas) the difference in a few afr points is not worth the gains to give up the reliability

[macca_779]

Alright, The first post you qouted of mine had the link in it. The link has the information that I assumed you knew because i thought you might have read a bit of it. Here are the steps of my convert to e85 went.

Ran out of gas.
Filled up with e85.
Changed to 80lb injectors and flashed the injector data to my car.
Scaled my maf table for idle all the way through wot. (I have my ve tables disabled)

I know the op from another forum and I know he knows how to tune ve/maf tables in. I was just lending a helping hand for him to keep things simplier.

And you still havent answered my question, how much ethanol experience do you have.

I know how to tune for Ethanol so I didn't bother reading your link. I've been working with ethanol at various times for about 3 years.

[superwagon]

I agree with macca and what Banish recommends. If you tune in lambda it takes any afr confusion out. Change your stoich to what you are burning and all other calculations will follow.

[elite_cyborg]

The highest horsepower tvs car was done this way.

[HNRClothing]

The highest horsepower tvs car was done this way.

Which way? with just keeping 14.7?

[imphat0260]

I agree with macca and what Banish recommends. If you tune in lambda it takes any afr confusion out. Change your stoich to what you are burning and all other calculations will follow.

Agreed.... This thread is full of laughs... Good luck blowing your sh!t up guys!

[DSteck]

Skatin, you should probably just bow out completely.

For what it's worth, I've done emissions studies and calibrations on alternative fuels for University of Michigan - Detroit, so I'm quite familiar with biofuel and ethanol.

You keep talking about gasoline and E85 having a "lambda ratio" of 1:1... This termonology is totally, well, dumb. ANY fuel has a STOICH VALUE of 1 lambda. 1 lambda for Gasoline is ~14.7, while 1 lambda for E85 is ~9.7. Rescaling the MAF is a fruit way to do it, because then any and all torque calculations in addition to cylinder load calculations are all off of what they should be, consequently compounding the problem of having to adjust MORE areas to make it "right". Just scaling the MAF up 30% when running E85 is not the right way to do anything. There is an entry for the stoich value of the fuel being used for a reason.

I can tune a car on pump gas, then fill it with E85, change the stoich ratio, and richen up the PE ratio for WOT... and it'll run without changing anything else. There's no point in building in error to your calibration when you can just do it the right way, which is actually the EASIER way.

[Jaxon]

steck knows his shit for sure. one badass z06 and has tuned ALOT of cars along with traveled out of the continent to tune cars aswell.

[elite_cyborg]

Which way? with just keeping 14.7?

Yes, by leaving it in 14.7

[BlackBaltSw]

Alright so i see that the right way to do it is to change the Stoich value to 9.765, so if i wanted to run an afr of 7.5 on WOT my Pe EQ would just be set at 1.302. What would my AEM Uego read at that point?

[mr.prick]

You will need to make a custom pid based off the Lambda range of the WBO2 and your stoich AFR.
Spreadsheet for this

[roderick]

Some of you guys need to study way more when it comes to e-85
taken from another thread on here.

http://www.hptuners.com/forum/showth...highlight=e-85
To get an accurate AFR reading you need to switch the meter to Lambda or equivalence ratio setting rather than AFR. Most O2 sensors assume you are running gasoline and will report a stoichimetric mixture as 14.7:1 which is the proper value for gasoline. E85 has a Stoichemetric mixture of between 9.7 - 10:1 and a max power mixture of about 6.98-8.5:1 or so, where with gasoline it is 12.5:1-to 13.1.

If you must use an O2 sensor that only reports gasoline AFR information simply divide the numbers it reports by 1.47 - 1.50.
The O2 sensors would still work. They don't understand AFR, they only understand rich/lean. If you are using regular or E10 the stoich AFR is ~14.7:1 (as you well know) and when the O2s are switching, this is the AFR it is indicating. When you are using E85 (AFR 9.765:1), the O2s will still work, switching between rich/lean. It's just that the point they are switching at is 9.765:1. You have to know what fuel you are burning to properly interpret the information the O2 sensors are providing.
Lambda 1 is always Lambda 1 no matter what you drive your car on, the o2 sensor doesn´t care if the AFR are 14,7 or 9.765... it measures the available o2 in the exhaust gases.

[macca_779]

Actually roderick E10 represents about a 14.0:1 AFR. Most people don't bother with it though as the trims have plenty of scope to run with it. But if you were planing on running OL and/or tuning VE, you would keep it in mind and adjust the stoich value. Personally I run Semi Open Loop SD. If on the odd chance I run E10 as opposed to gas I don't bother making any changes. But I'm just lazy with my own car I guess.

[Terminator2]

Yeah and watch your trims max positive quick smart.

If you run an ethanol based fuel.. You MUST alter the Stoich value to suit. PE tuning in Lambda is very similar though, if anything you can run a little leaner.

This. If you leave stoich at 14.69.... the O2 sensors are going to sense the difference in O2 concentration and are going to add 30% fuel (STFT +30). The car will run lean until it compensates and if you are on narrow band sensors (LNF cobalts have a WB O2) it will not compensate properly at WOT.

[Terminator2]

Skatin, you should probably just bow out completely.

For what it's worth, I've done emissions studies and calibrations on alternative fuels for University of Michigan - Detroit, so I'm quite familiar with biofuel and ethanol.

You keep talking about gasoline and E85 having a "lambda ratio" of 1:1... This termonology is totally, well, dumb. ANY fuel has a STOICH VALUE of 1 lambda. 1 lambda for Gasoline is ~14.7, while 1 lambda for E85 is ~9.7. Rescaling the MAF is a fruit way to do it, because then any and all torque calculations in addition to cylinder load calculations are all off of what they should be, consequently compounding the problem of having to adjust MORE areas to make it "right". Just scaling the MAF up 30% when running E85 is not the right way to do anything. There is an entry for the stoich value of the fuel being used for a reason.

I can tune a car on pump gas, then fill it with E85, change the stoich ratio, and richen up the PE ratio for WOT... and it'll run without changing anything else. There's no point in building in error to your calibration when you can just do it the right way, which is actually the EASIER way.

This is 100% correct. It is stupid to rape your MAF tables in order to fix and A/F value due to a change in fuel used. It is so much easier to use the correct stoich value for E-85 or whatever type you are using and then adjust the PE EQ ratio. It this case this is both the easier way and the correct way as well.

[skatinboarding]

Holy crap I forgot about this thread. Im not going to just bow out. This is good technical talk you guys are bringing into the conversation. Its worthless to keep fighting about it though. I understand that changing it to stoich e85 is the proper way to do it but this is working well for me and many others that I know. I am not doubting anyone's tuning ability but Im just saying it works. When something goes wrong Ill be the first to admit. Fuel trims are perfect and I dont really see it as "raping" the maf scale. Its there for this reason.

So I have a question for all you doubting this method, as I am open ears at this point,

If I put 80lb injectors in and flashed the tune with a full tank of pump gas, tuned every bit of the maf in (100% maf) good and good. Then ran out of fuel, filled the tank with e85, changed the stoich value to 9.75 or whatever it is, Would the maf scale line straight up? Or would I, quote on quote, be raping the maf scale while tuning it in? Either way, if im thinking right, it still requires 30ish% more fuel needed or does just changing the stoich value change that? Because that is what it sounds like you guys are saying.

[macca_779]

Holy crap I forgot about this thread. Im not going to just bow out. This is good technical talk you guys are bringing into the conversation. Its worthless to keep fighting about it though. I understand that changing it to stoich e85 is the proper way to do it but this is working well for me and many others that I know. I am not doubting anyone's tuning ability but Im just saying it works. When something goes wrong Ill be the first to admit. Fuel trims are perfect and I dont really see it as "raping" the maf scale. Its there for this reason.

So I have a question for all you doubting this method, as I am open ears at this point,

If I put 80lb injectors in and flashed the tune with a full tank of pump gas, tuned every bit of the maf in (100% maf) good and good. Then ran out of fuel, filled the tank with e85, changed the stoich value to 9.75 or whatever it is, Would the maf scale line straight up? Or would I, quote on quote, be raping the maf scale while tuning it in? Either way, if im thinking right, it still requires 30ish% more fuel needed or does just changing the stoich value change that? Because that is what it sounds like you guys are saying.

In theory yes you could simply change the stoich value and all would line up. The reality is that it won't be 100% bang on due to other aspects of changing the fuel. ie energy content, MBT timing and so on do effect VE. But it will be 95% correct and well within the scope of the fuel trims to soak up any errors if you left everything else alone.

Changing the stoich value, the PCM will automatically know it needs ~30% more fuel as you have changed the AFR ratio for stoich.

[DSteck]

Holy crap I forgot about this thread. Im not going to just bow out. This is good technical talk you guys are bringing into the conversation. Its worthless to keep fighting about it though. I understand that changing it to stoich e85 is the proper way to do it but this is working well for me and many others that I know. I am not doubting anyone's tuning ability but Im just saying it works. When something goes wrong Ill be the first to admit. Fuel trims are perfect and I dont really see it as "raping" the maf scale. Its there for this reason.

So you understand it's the proper way, yet you promoted the SHIT out of the wrong way, which also happens to be a more involved way? I had talked to Greg Banish about something sort of similar in regards to stoich values correlating to the fuel being used, and he mentioned that your transient fueling becomes inaccurate if you don't use a correct stoich value. So, yet again, another problem with just wrecking the MAF.

So I have a question for all you doubting this method, as I am open ears at this point,

If I put 80lb injectors in and flashed the tune with a full tank of pump gas, tuned every bit of the maf in (100% maf) good and good. Then ran out of fuel, filled the tank with e85, changed the stoich value to 9.75 or whatever it is, Would the maf scale line straight up? Or would I, quote on quote, be raping the maf scale while tuning it in? Either way, if im thinking right, it still requires 30ish% more fuel needed or does just changing the stoich value change that? Because that is what it sounds like you guys are saying.

"quote on quote" Haha. The phrase is actually "quote, unquote"... but when typing it, you simply use quotation marks. Hahaha. Good Friday morning laugh.

Anyway, if you tune the car properly on normal gas, run the tank out completely, and then fill up with E85 while correcting the stoich value, then that's all there is to it. Your timing strategy will change, and you'll want to change the PE multiplier (gasoline prefers about 0.85 lambda for peak power during WOT, whereas E85 is better off richer, maybe 0.8 or 0.75), but everything else stays true.

The stoich value gets used in calculations. If the PCM is measuring 20 lb/min of airflow, and the stoich value is entered as 14.68, then it's going to try and deliver 1.36 lb/min of fuel. If you change the stoich value to 9.75, then at 20 lb/min of airflow, it's going to try and deliver 2.05 lb/min of fuel. Airflow and the stoich value are directly used to determine how much fuel to inject... and that's why it's the RIGHT way to do it.

[skatinboarding]

But the thing is that everything is read off of lambda... ahh this is going nowhere. I know its working for me and countless other people I have talked too. Thanks for all the advise though. It honestly has helped me understand more about e85 and tuning. I did a lot of research and talked with a few shops that are big e85 tuners around here and they all said it was the same thing in the end. If something goes wrong I will bump this thread up and let you know.

[Japeatr]

can someone wrte up a procedure for changing the fueling tables to switch over to E85?

im reading thru Cpigs writeup like it is the holy bible, and something like this for going pump to E would be greatly appreciated