id change it back honestly. the car will adjust itself. this is why you have fuel trims.

 

I heard if you just change the stoich it adjusts itself. So if you don't change the stoich wouldn't your maf scale be totally incorrect?

just playin d.a. here..

 

Maybe I am missing something here, but I don't really see how stoich value will **** with your power output. I mean, when your WOT and in PE, your commanding AFR in open loop is still going to be the same as long as you got it tuned accordingly each way and with a wideband.

I mean, I could see you out running the timing table or something if your MAF and airflow numbers are that far off because of the stoich value. But if your completely tuned around it (even timing map adjusted accordingly)... open loop should be the about the same either way.

 

your pe is based off the stoich. we know this.

leaving your stoich at 14.7 leaves you lean all over.

setting your stoich to 10.4 sets you right in the happy zone of the ethanol. give or take how it's blended.

any direction you want to do this, you have to tune the maf. the car was never designed to run e85, so the corrections are not there.

keeping you numbers in the timing map, or half ass on scale. who cares. it holds the last cell, or rows. same with the maf at 11k. you can half the entire map to keep it in scale if you so desire. purely up to you.

i know my preferred way of doing it may not be the same as everyone else's.

 

All I meant was, if you have stoich set to 14.7 and PE at about 1.9. Or have stoich set to 10.4 and PE set to 1.35. In the end, you have a AFR of 7.7 for E85 in open loop. Now if MAF and timing are set according to each setup, I would think power would be near identical in open loop.

I am still learning as I go here, I could be completely wrong.

 

i never got bored enough to spend the time to find out honestly. raping the maf table to run e85 because one doesn't change the stoich has a lot of free time on their hands and doesn't like maximum power.

 

Oh I agree. I was just arguing for curiosity's sake, lol.

I don't see the reason why people keep stoich @ 14.7 when running E85. Should consider themselves lucky for even having the option because a lot of cars don't.

 

because most people are idiots.

 

so I have a question. if you have a wideband that richest it reads is 10.00 and leanest is like 17.00, how would you read it with e85? Do you read it as if you were reading unleaded?

 

lambda converted
1.0 gas
1.0 ethanol

it will read the same on the sensor end of it.

 

Yup your WB will show the same AFR as pump gas but that 14.7 value is not actually 14.7.

 

I was one of those idiots but am now running the correct stoich.

Honestly it was easier to multiply the maf than to just change the stoich value for me. There was a lot of tweaking I had to do to get it to run right (and yes the maf was changed back to before it was raped). Ultimately I started from scratch and used different injector settings and got it running good.

Another point that I would like to comment about it is that it felt almost the exact same other than it shaved a little of my ricer 60-100 times. I never did get around to getting to the dyno again to see how much it helped. I honestly dont see how it can help much but Ill take area's word on it and shut up now.

Moranjames89 there is a thread on the rlforums under the tuning section showing how to set up a custom pid for e85 error. On the gauge it will read gas settings still though. Unless you have the lc1 and you can change it to read ethanol.

 

so 14.7 is actually what?? I plan on switching, but I don't want to blow my **** up because I didn't understand the wb

 

Lack of proper fueling at 14.7 vs 10.4

 

so 10.4 would be ideal as 14.7 is stoich w/ 93 octane.?
unmodified wb o2 mind you.

 

So by using 10.4 as stoich when running E85, that allows for a greater margin of error since most stations aren't EXACTLY 85% ethanol. Even though lambda 1 of "e85" is 9.765.

Is that right? I plan on switching to 80's and running E85 in the spring, so I've been researching a lot about it in my free time.

 

No. You WB will read 14.7 since it is set up for pump gas stoich (14.7:1). If you set the stoich in the tune to 10.4 that 14.7 that the WB is showing would actually be 10.4 afr...

 

no, leave it at 14.7 for pump gas.

 

Bryan, I think he was asking about if WB gas AFR of 14.7 equals E85 AFR of 10.4, which it does as the WB is reading the same lambda, but displaying it differently. It was kind of a confusing question the way it was worded..

You bring up a good point of the 14.4 vs 14.7 stoich for E10 however... Can you give a quick explanation of why you don't like setting pump E10 to 14.4?

Many people on the HPT forums and other places I have read are using the 14.4 to 'split the difference' of E10. I personally am running 14.4 stoich and I have my tune dialed in perfectly at cruising speeds using dynamic airflow till 3K. My trims seem to be much better using 14.4 over 14.7, however I never did a complete back to back comparison. It could simply be because I have spent more time tweaking the 14.4 settings.

 

yes but you're preferred way of doing things have gotten you some impressive numbers too


just so i am getting things right...


the stoich value that is being discussed, is it in relation to how lean/rich the mixture is?
e.g. = a highner # means it's leaner or whatnot

or am i missing something else?

 

stoich determines how the ecm calculates wot afr, and part throttle afr. if you change it .5 watch what the trims do. you wot fueling in pe is based on this as well

 

area, if you send me a .hpt with an e85 tune for my mods that you think will be at least close I'll give you $50
I've been messing with my tune FOREVER and just want it to run okay at least...

 

i could setup a base tune

 

I mean I've got the problem tunes on e85 off hptuners, but all I want for now is my car to idle good and run decent and I can take care of the rest. otherwise I'm going to have to go with a cann tune from ottp

 

Canned tune will make it worse. Those tunes are for the people that are waiting to get custom tunes done. lol It is so it will start their car after all their mods and be able to drive to the tuners location.