tuning e85 in winter?

[vic_s197]

I'm wanting to get my car retuned sometime in the next month, I'm running an f1a at 18-20 psi and 13 degrees of timing on my 05 gt and putting down 691 rwhp at 6000 rpm. I want to get more Out of it cuz I'm running out of gear at the end of the track . But I'm trying to figure out if I should wait to re tune it in the spring or should I go ahead and do it now? This is my first time working with e85 so I wanna make sure I do it right. And iv heard from some guys say cars running on e85 tend to run like shit in the cold weather is that true?

 

[9BABCobra8]

I am no expert on e85...

The first thing you should do is test your ethanol content of the blend. This will vary by location. The winter blend for Minnesota will differ from the Houston winter blend. This will be important to understand where you want your AFR to be. The minimum content from what I have read can be anywhere from 51% to 70% ethanol. Usually, from the summer to winter blend you will just run slightly rich. Now tuning for winter and going to the summer blend you could result in a lean condition.

Taken from:
E85 Mustangs.com - Tuning for E85
Let's look at the flip side going from Winter Blend to Summer Blend during the Spring time. What happens here is much more important, because now we are going from less ethanol content (70%) to more ethanol content (85%) and that will potentially cause a lean condition. As we all know, lean is great on your wife or your grilled chicken, but certainly not on an internal combustion engine! As mentioned above, the maximum range it should fluctuate at WOT, is 1 full point on your gasoline AFR gauge. If you were previously at 11.8 AFR with the pedal to the floor, it could potentially go up as much as 12.8, but more likely around half a point at 12.3. When performance tuning, this could be a critical mistake that causes engine failure. The high octane is much more forgiving than gasoline but the longevity of your motor ultimately depends on how safe your tune was built.
During the transition months of Spring and Fall, it's even more difficult to know what class of E85 you're buying and testing your fuel as mentioned above is even more important. For the best results you will need two variations of the tune to load (winter and summer). The SCT Xcalibrator 3 is a great tool for choosing between load files, or the use of an SCT flip chip.
If multiple tunes are not possible, you're better off building your tune with Summer Blend (85%) and letting the car go more rich in Winter, so that you will be right on target again when warmer temps return during racing season.

 

[65fastback2+2]

you want to tune on summer e85 so that it goes slightly richer during winter so you dont have to retune every time the seasons change.

 

[vic_s197]

Il test it this weekend, but I think Il polly wait till spring to re tune it

 

[JohnnyRocket4v]

I was also wondering this. Isn't there something you have to do in your tune so the computer doesn't add timing

 

[nonliberal]

My tuner and I decided it's best to run 93 octane in the winter since it's hard to get traction with cold streets and tires in the winter anyway.

Then just switch back over to e85 in the spring. It's saves a lot of hassle and more than doubles my fuel milage in the winter since I average 12 mpg on E85 and 28mpg on 93.