E85 tune, driveability issue

[AlteredBe4st]

I have a dedicated E85 tune and previously I flashed the tune ( BM3 ) then filled up with tested E85 and upon driving I noticed my car breaking up on high throttle 5500rmp and up, gradual driving the car drove fine. At high throttle the car would sometimes pull through and clear up, running smoothly, continued driving and drivability got worst constant break up only at full throttle, so went home reflashed the E85 tune twice, same issue, next day the car went into drivetrain malfunction and then threw me into limp mode, so I decided to change all spark plugs, same NGK 97506 gapped at 0.020, cleaned MAF sensors and change all coils, car did the same thing, so before going down the rabbit hole and throwing more parts at it ( injectors ) I decided to drive the car until the E85 was low, at 5 miles left, I filled up with 93 octane flashed back to my 93 tune and the car drove flawlessly, my question is has anyone experienced this issue? Previous to this issue I had no problem with the E85 tune, I normally fill up at a reputable E85 station in Greenwich Connecticut. My friend M3 F80 running on flex fuel is experiencing the same issue while another friend that drives a Modified Evo on flex has no issue all three cars using the same station same fill date 🤷🏽‍♂️ strange!!

[NoorSinghJohal]

Which e85 tune are you running, I was having the same issue on occasion at high rpm

[MineralWhiteF80]

Do you have an ethanol sensor installed to see real-time ethanol percentage? As you know, E85 does not mean "85% ethanol." It really means "somewhere between 51% and 85% ethanol depending on many factors." So it is possible that your E85 tune could be too aggressive for the actual ethanol percentage being provided at your gas station. Without knowing the specifics of your E85 tune, who did it, and its fuel/boost maps, it will be hard to tell for sure what is happening= like not running enough ethanol that the tune requires, or maxing out your fuel pumps/injectors, etc.

I think that was always my hesitation of choosing between an "E85 tune" and a "flex fuel tune" that could account for different percentages of ethanol. For example, both my e92 and f82 run on E85 flex fuel tunes, but I see pump E85 in my area actually between E60 to E71.

[AlteredBe4st]

Originally Posted by NoorSinghJohal

Which e85 tune are you running, I was having the same issue on occasion at high rpm

I’m running a dyno tuned, custom tune by Cary Jordan

[AlteredBe4st]

Originally Posted by MineralWhiteF80

Do you have an ethanol sensor installed to see real-time ethanol percentage? As you know, E85 does not mean "85% ethanol." It really means "somewhere between 51% and 85% ethanol depending on many factors." So it is possible that your E85 tune could be too aggressive for the actual ethanol percentage being provided at your gas station. Without knowing the specifics of your E85 tune, who did it, and its fuel/boost maps, it will be hard to tell for sure what is happening= like not running enough ethanol that the tune requires, or maxing out your fuel pumps/injectors, etc.

I think that was always my hesitation of choosing between an "E85 tune" and a "flex fuel tune" that could account for different percentages of ethanol. For example, both my e92 and f82 run on E85 flex fuel tunes, but I see pump E85 in my area actually between E60 to E71.

No I don’t have an ethanol sensor but strange thing is that my friend has an F82 running flex E50 tune and he had the same issue while my other friend with a modified Evo has no issues, I will ask my Evo friend what his sensor is reading because my tune requires full E85 even though I did a test prior.

[MineralWhiteF80]

Originally Posted by AlteredBe4st

I’m running a dyno tuned, custom tune by Cary Jordan

The only thing I would do then is shoot him a quick email with your concerns. He would know better than anyone what the best way forward is. Maybe (hopefully) you just got a low percentage ethanol blend that one fill up and nothing is actually wrong.

[MineralWhiteF80]

Originally Posted by AlteredBe4st

but strange thing is that my friend has an F82 running flex E50 tune

That is interesting because a flex fuel tune should adjust on the fly for a lower ethanol percentage. If your friend has a flex fuel tune on his f82, then he should have an ethanol sensor installed where he can read E%. On my f82 i can read ethanol percentage by just moving cruise control toggle switch down one click and the E% shows on my tachometer (super handy).

[n8dgr84]

Spark blowout?
You should be running the F8S plugs at .022" gap.

[DeTh]

Do you have EU5's? If you are stock injectors EU6, change them immediately. CaryJordan blew my motor on EU6's by saying that it would be fine to run them on full E85. The rail pressure was too high, one got stuck open and threw two holes in my block. My first signs (in hindsight) was the occasional break up on WOT at around 6k RPM. Cary told me to disregard and chalked it up to a bad tank of gas. A month later I lost the whole motor. 23k miles.

[AlteredBe4st]

I have stock injectors, never had an issue prior but I will look into the EU5