E85 max power ratio questions

[bluegoat06]

Normal aspirated application.
For what i've seeing online,

max power rich for gas is .85 lambda
and max power lean is .90 lambda

max power rich for E85 is .71 lambda
and max power lean is .86 lambda

I'm pretty conservative in my tunes, so i shoot for .85 lambda on gas all the time. not because i've read about it, but because all my cars had always run better at .85 compared to .90 at WOT

Should i go that rich on E85 (0.71 lambda) since it seems to be the equivalent of .85 lambda with gas ? that seems super rich, but i'd like to hear from you guys who have had more experience with E85

I'm experimenting with E85 in my own car, G8GT, Stock L76 engine with headers and CAI, and like to have a good solid tune for E85.

Thanks a lot.

[bluegoat06]

Anybody ?

[LazMan]

Ive used E85 on my GXP M6. In my experience:

Good rich Power for E0 or E10, 1.176 PE, 0.85 lamda
Good lean (but safe because of higher fuel flow) Power for E85, 1.15 PE , 0.87 lamda

This basically means I keep the PE at 1.176 for E10 or E85 (Straight gas is hard to get in FL).

The much higher stoich starting point for E85 means there is TONS of fuel flow to keep the pistons cool at E85's "lean" power. "Rich" power with E85 is a waste of fuel.

Just be sure to use the right stoich values in the first cell of your Stoich table! (More for passers by than for you, as Im sure you know this.)

I extrapolate the GM stock values, and use:

E10: 14.108398
E20: 13.538574
E50: 11.828125
E85: 9.832520

-Laz

PS: Wow, hadn't posted in ages! :-)
PSS: I use 1.176 PE (.85 lamda) too.

[bluegoat06]

Thanks Laz

[DSteck]

Depends on the application. I'm running my buddy's 441 LS7 with 9.4 DCR at .82 lambda on E85. Seems to be what it likes best, but this is a unique setup built specifically for E85.

[bluegoat06]

I'll check what my car likes the most at the track. i have a tune with .80-82 lambda, and another one with .77-.78 lambda. I've checked E85 performance web site, and most people talk about .76 through .80 for max performance for N/A applications, setup dependant since not all cars react the same.

[bluegoat06]

Is there something we can do to get better MPG out of E85 ?
Highway driving is not that bad, city driving sucks though, i guess she loves the moonshine a lot

I've already added 3* more timing in cruising areas and while MPG's have improved, they're still bad, and i mean i'm getting 120 miles less, out of a 18 full tank compared to 91 octane E10 gas i pumped normally. Normally i get 380-400 miles out of 18 gallons (city/highway combined), on E85 the best i've got was 260 miles out of the first tank, and the 2nd one i'm running right now would suffer the same fate, although, i've been making WOT runs to test fueling and timing so the comparison is not exactly fair.

[bluegoat06]

Here is one of the tunes i'll try today

[carlrx7]

id shoot for max power lean .86

[Rebel_Kings]

Is there something we can do to get better MPG out of E85 ?
Highway driving is not that bad, city driving sucks though, i guess she loves the moonshine a lot

I've already added 3* more timing in cruising areas and while MPG's have improved, they're still bad, and i mean i'm getting 120 miles less, out of a 18 full tank compared to 91 octane E10 gas i pumped normally. Normally i get 380-400 miles out of 18 gallons (city/highway combined), on E85 the best i've got was 260 miles out of the first tank, and the 2nd one i'm running right now would suffer the same fate, although, i've been making WOT runs to test fueling and timing so the comparison is not exactly fair.

the less compression your motor is the less ethanol you should use.
i run about e40 in my 3.9 g6 and im averaging 24 city and 28 hwy with the f40 six speed.

high compression motors benifit from ethanol alot. my car on e10 has kr in almost every gear at full throttle stock. slight tune with a little bit of timing advance with some e40 and im getting the same mpg as i did with e10 with absolutely no kr.... but of course at full throttle the ethanol goes a little bit quicker of course.

BUT to answer your question when your driving around on the street use less ethanol in your gas e30 is the magic number according to some new studys on flex fuel impalas.

[LazMan]

Well yes, what works best on a particular car is what you want to run ...

...I'd say use 1.17 (.85 lambda) as a safe starting point. Unless you're running some blown or extremely high compression set-up, it is a safe starting point, providing plenty of cylinder cooling via the volume of fuel in my opinion.

[09G8GT!]

good morning, would anyone happen to have a base tune for 2009 g8 gt for e85/ flex fuel? recently installed the flex fuel kit and wanted to upload a base tune to be able to move the car around on e85.

[horsepowerguru427]

good morning, would anyone happen to have a base tune for 2009 g8 gt for e85/ flex fuel? recently installed the flex fuel kit and wanted to upload a base tune to be able to move the car around on e85.

Start a new thread with that question and include all mods and injector part number being used on the vehicle. Youll find there are a lot of people who wont help when you revivie an old thread like this. Just a heads up! Happy Tuning!

[09G8GT!]

thank you! just started a new one.