Tuning for new E10 fuel
Tuning for new E10 fuel I am doing some remote tuning for a friend of mine with a 2013 sierra flex fuel truck being done by a very reputable tuner and I noticed that his commanded afr is set to 13.7ish and 11.5ish at WOT and when I asked the tuner about it he said it was because the 20% alcohol the truck is reading in the fuel.
It got me to thinking about my trucks and vett that I have tuned which are all set to the normal 14.7 and 12.8ish at WOT verified by a wideband and the all run great and have been for a long time. Should I be running it richer for the ethanol that is now being put in our fuels? I know the sticker on the pumps say "may contain up to 10% alcohol" so should I adjust my tune for it? What about timing? I run them all at 26-27* at WOT.
It got me to thinking about my trucks and vett that I have tuned which are all set to the normal 14.7 and 12.8ish at WOT verified by a wideband and the all run great and have been for a long time. Should I be running it richer for the ethanol that is now being put in our fuels? I know the sticker on the pumps say "may contain up to 10% alcohol" so should I adjust my tune for it? What about timing? I run them all at 26-27* at WOT.
26-27 degrees of timing is more than I run in most of my stuff...I usually keep everything around 24-25 tops...a few cars at 26, but not often.
so if i tuned it with a wideband at 14.7 and 12.8 WOT with the same fuel then it should be right anyway because the e10 was accounted for and the proper amount of fuel was already added?
Staging Lane
Joined: Oct 2012
Posts: 54
Likes: 1
From: Calgary Alberta Canada
If everything was spot on with pump gas...you're right...but if it was spot on with E10 and the stoich AFR set to 14.7, then it will actually kinda throw it off.
26-27 degrees of timing is more than I run in most of my stuff...I usually keep everything around 24-25 tops...a few cars at 26, but not often.
26-27 degrees of timing is more than I run in most of my stuff...I usually keep everything around 24-25 tops...a few cars at 26, but not often.
Trending Topics
That also assumed your E10 was actually 10% ethanol. Pure gas is better to tune with as you know the exact mix. Then do the 14.2 or w/e after.
If your WB reads 14.7 and 12.8 you're gtg(assuming you have it set to a pure gas scale). It reads lambda and converts the AFR. No matter what fuel you use, stoich is lambda 1.0. So without changing the settings in the wb, stoich is always 14.7 on the wb readout.
If your WB reads 14.7 and 12.8 you're gtg(assuming you have it set to a pure gas scale). It reads lambda and converts the AFR. No matter what fuel you use, stoich is lambda 1.0. So without changing the settings in the wb, stoich is always 14.7 on the wb readout.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
TECH Regular
Joined: Jun 2012
Posts: 414
Likes: 5
From: SV, AZ
Pure anything is difficult to find. Especially gasoline.
You should tune on the fuel you plan to run. If that's pump then I'd use the pump you'll use most. Yes I know they might get bad batches, change suppliers etc. We're just doing the best we can to add controls.
You stay open loop and tune pure gasoline with a stoich setting of 14.7. Everything's great until e10 goes in the next tank. I understand it's only ~4% difference. But it's 4% on the lean side. If I do the opposite, tune e10 with a setting of 14.11, then put in pure gas on the next tank I'm gonna end up ~4% rich. Which for WOT safety reasons is where I'd rather be.
All of this is based on pump fuel tuning and is my opinion. It's how I build a little safety barrier into my pump fuel tunes.
You should tune on the fuel you plan to run. If that's pump then I'd use the pump you'll use most. Yes I know they might get bad batches, change suppliers etc. We're just doing the best we can to add controls.
You stay open loop and tune pure gasoline with a stoich setting of 14.7. Everything's great until e10 goes in the next tank. I understand it's only ~4% difference. But it's 4% on the lean side. If I do the opposite, tune e10 with a setting of 14.11, then put in pure gas on the next tank I'm gonna end up ~4% rich. Which for WOT safety reasons is where I'd rather be.
All of this is based on pump fuel tuning and is my opinion. It's how I build a little safety barrier into my pump fuel tunes.
I honestly never had an issue finding "pure" gas when I'm doing my initial tuning. There are usually a couple stations that go out of their way to advertise ethanol free gas and I'm from the heart of corn country. :-) Once I'm done with the initial tuning I go back to the ~E10 stuff.