Another E85 thread
Say i get the car tuned on the weaker E85 (winter/spring blend) and then summer rolls around and the good stuff comes, do i need to retune the car?
This isnt a max power effort. i want to run E85 for its safety factor in the sense that it doesnt detonate. My thought is that if i tune on the weak(est) stuff and run summer the blend, itll only aid in preventing detonation. Whereas if i tune on summer blend, ill have to worry about when the weaker stuff is here. The other question i have is will the different blends affect my AFR?
I havent ever really dealt with fuel systems before so im curious if my thought process is correct?
Last edited by Ryans99ls1; Feb 25, 2012 at 02:55 PM.
maybe its easier to see what im asking when i put it this way.. these are hypothetical numbers.
Scenario 1:
Tune on the car gets done with winter/spring E85. Max timing of 14 and an AFR of 11.0:1. Now summer comes around and i know the octane rating goes up, which is a good thing. here ill just have to keep an eye on my AFR to make sure it doesnt go lean.
Scenario 2:
Tune on the car gets done with summer E85. Max timing of 14 and an AFR of 11.0:1. Now fall comes around and the octane rating of E85 DROPS. With a tune like this (on the very conservative side) do i have to worry about a re-tune because the octane change? There is also the fact that the cooler air will increase the power output and ill be running a fuel with a lesser octane rating than what i tuned with(for this scenario). This is what im truly worried about.
Will the change in octane change the fuel demands?
also, whats an all around safe AFR with E85? i was reading high 10's?
I dont get to drive my car much over summer because of work. Fall is when i really get to play with it so im just worried about the drop in octane rating+cooler air effect and how my tune should be setup
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with boost references regulators ive seen them go well over 500. But adding a second pump isnt a big deal. ill take care of that if it comes to.
with boost references regulators ive seen them go well over 500. But adding a second pump isnt a big deal. ill take care of that if it comes to.
the goal is 500, and if it hits 500 with less than 8psi then i may still go up to 8psi and see what it makes. Dyno wise i could care less really, my main goal is just shy of 130mph traps
Last edited by Ryans99ls1; Feb 25, 2012 at 05:59 PM.
Here is a quick video from the other day after driving it 170 miles on a full tank of fuel where I averaged 15mpg's. Enjoy. At a 45 mph roll in 2nd gear it roasted the tires and immediately hit the rev limiter, but was gone in 3rd!
http://www.youtube.com/watch?v=2KExIIYdzNk
Here is a quick video from the other day after driving it 170 miles on a full tank of fuel where I averaged 15mpg's. Enjoy. At a 45 mph roll in 2nd gear it roasted the tires and immediately hit the rev limiter, but was gone in 3rd!
But like i said im really interested in how the car will react when fall hits with the different blend and those cool nights(aka really low IATs) are here. I mean the car will definitely be making power on those nights and i dont wanna crack a ringland cus the tune was setup for summer blend. scooter k basically answered that though.
thanks for all the help guys. and for the record, the car is getting a lonnies dual setup.
Going to tune my car with 22psi boost on winter e85 soon.
Good luck! Measure the blend before you tune

EDIT: If you can tune on summer it is probably the best. Not possible to get here in Norway without making it myself. Thats why i run what ever i can get. I dont know how it is in usa but here, one station can have summer, one will have winter and the third one might have a mix. It is important to have the engine running on all variants without trouble or new tune.
If someone could make the stock ECU work with input from a alcohol meter i would buy one!
Last edited by RexDiablo; Feb 26, 2012 at 01:08 PM.
Ive read a few E85 threads and seen what people shoot for, but i havent seen much of what people are actually running
I like to use e85 to keep things colder so i might run richer than most?
Timing is around 19degrees but ive seen people running 24 etc at wot. My car is track only and has to handle alot of abuse.
The point is that your engine (if used winter-summer) has to handle the different qualities of e85. Ive talked alot about this in norway but no one seems to agree that the changes in e85 (e70-e85) has something to say! It would be cool if someone did a real test. It can be calculated but i like real tests.
EDIT:
e70 stoich afr is 8.5% higher than e85. So it should be a problem if you map on winter e85 or either way if you arent pushing limits?
Last edited by RexDiablo; Feb 26, 2012 at 04:37 PM.









