OFT e85 tune question
 

was watching youtube video on flashing e85 OFT tune, it says wait until fuel light comes on and then add in some e85 and then drive around with the current petro tune while monitor the ST and LT fuel trims to rise. only flash the e85 tune when ST and LT fuel trims rise up to certain level. can anyone confirm this? and exactly what level those fuel trims supposed to be before i can flash the e85 tune?

The car will run e85 with a gas tune (albeit shitty) but vice versa could be harmful to engine.

so the youtube video was wrong? what's the proper way of flashing e85 OFT tune? can anyone list the steps by numbers? much appreciated.

found this thread and it suggests the same as the youtube video, leave petro tune in after fill up with e85 for the first time and monitor the fuel trims.

http://www.ft86club.com/forums/showthread.php?t=67310

• Run tank down till low fuel light comes on
• Fill with E85
• Plug in OFT to monitor fuel trims (leave petrol tune in at present)
• Drive slowly below 3500 rpm no WOT or hard acceleration until you see STFT rise rapidly followed by LTFT and stay high, this indicates that the petrol is now out of lines and the E85 has made it through the lines and pumps, this generally takes 2 or 3 km
• Pull over and turn off car Flash E85 tune with OFT (Stage 2 EL E85) for stock car or car with EL headers or Stage 2 UEL E85 if you have UEL headers.
• Start car and drive slowly again below 3500 no hard acceleration for next 10 to 20 km until your fuel trims LTFT/STFT stabilise below about 10% while cruising and idle, this allows ECU to learn the E% of your E85 mix.
• Then do two or three light steady throttle (about 10-20%) runs in second or third gear 2000 rpm to 6000rpm (just let the rpm's build slowly), none of this is 100% necessary it just helps ECU learn quicker
• If you do flash the E85 map at the pump on switchover the learning process will take longer as the E85 tune will try to learn petrol then when the E85 gets into the system it will need to learn E85.

When the STFT started to go way up to 20, I pulled into a CVS parking lot and flashed the E85 tune. Then I drove easy for about 20 miles and watched fuel trims. I didn't do a pull for about another 50 miles. Basically you want to get the E85 into the fuel system and into the engine THEN flash and don't want to stress the engine until the LTFT are learned. Get the tank as low as possible on regular gas and fill up with E85. The E85 OFT tune is very forgiving of various %s of ethanol so a gallon of gas left in the tank is no big deal at all. Stylgrm3 post above is right on.

The idea is not to switch to e85 tune til you're burning e85. E85 tunes have much more aggressive timing than gas tunes.

Really debating whether to go with e85 tune, its free hp gain, but I’m concerning the car wasn’t designed to use e85, will switching the fuel cause long term damage to the fuel system and/or motor?

There are many people on here that have run e85 for 50k+ miles with no issues.

http://www.ft86club.com/forums/showthread.php?t=113819
http://www.ft86club.com/forums/showthread.php?t=115529
http://www.ft86club.com/forums/showthread.php?t=124769

As stated above, many people have run it for many miles and have been fine. However, if you’d rather be safe than sorry, just get a flex fuel kit to compensate for all the different ethanol percentages.

I’m actually going to try the E85 tune next week with the OFT since I’m confident from reading up that the car will be ok for my purposes (DD, no track use). There’s always a risk when modding your car, how much of a risk and if it’s worth the risk is subjective though. Be careful and good luck :D

I was a bit nervous to switch at first but been running E85 for months. No issues and real Nice power boost.

alright, i think i'm gonna give it a try, just loaded both stage2+ e85 and regular stage2+ onto my tablet, i will flip a coin after i install my header to see which one i will pick lol

If you fill up with E85, then install header, then switch tunes you’ll be shocked at the difference.

are you suggesting to do the stage2+ e85 tune first on stock header and then install the header? no need to do another tune since stage2+ with e85 covers them all.

Im on stock headers and using stage2+ e85 which happens to be the only e85 file (v4). Running just fine since v4 was released. Previously running v2 EL stage 2 e85 for months. Now finally getting a header on wednesday.

IF all goes to plan ill see a difference which is what i want. Cant do much na, but doing each in steps feeling the difference after each adjustment is nice :)