For the past month I have been back in forth on whether to go with an E85 tune in the spring and it would be a super easy decision but the fact that E85 can be
E70 to E90 straight sucks. How would you tune for that? Just tune for the E70 since that would be your worst case scenario? I am just looking to see what other people have done. I don't' want to be modifying my tune every time I fill up because the % is different.

 

well they do sell a guage that reads what ethanol percent the gas is.

 

E70 is still way higher octane than 91 or 93 octane premium. You could get tuned for e70 and with e85 you'd just be leaving a little on the table.

I think the overall benefits outweigh this one issue you are mentioning. but thats just my opinion.

Good Luck

 

Tune for both, the main difference will be the AFRs and then slight adjustments to the timing between the 2. Once you are tuned for E70, E85 is cake.

 

Most places will sell e85 during the warmer months. We only get e70/e78 during the winter months here in the desert.

 

I looked at a chart that someone posted on here showing each state and what class of E85 they were getting in each month and for me July was the only month with class 1 and all the surrounding months until winter were a class 2 or 2.5. I would like to here from CWill and the guys from AWD Motorsports since they seem to be the guys that are making awesome power with E85 and you see about every car coming out of there with a tune for E85. Just curious how they tune the cars considering the fluctuation in E85.

 

1. Tune for E85.
2. Have an AFR gauge, ethanol content gauge, or Tephra knock light mod.
3. Pay close attention to #2.
3. If need be, lower the boost a wee bit if ethanol content changes to a lower value.

MrFred is working on a true flex-fuel option for our EVO ECU. Look for his threads.