[ThatRWD]

And also wondering why does my care take so long to realize E85 has been put in there? Normally takes about 15-30 miles before it recognizes it.

07 E92 335i, JB4 Map 5, 56K miles. Map 7 made it poop and stop in the middle of the road.

[335NJ]

Short answer: if your car is stopping in the middle of the road to poop, you have a mechanical issue with the car.

[musc]

A backend flash alters variables like fuel scalar, Air/fuel, timing, vanos, etc to work in conjunction with the JB4. A lot more info about it on N54tech.

[Milan]

A backend flash is a real tune. You actually change the parameters of the ECU. Cobb is an example of a backend flash.

The BMS backend flashed just keep the JB4 for controlling boost.

[csu87]

There is a thread posted by i think shiv that showed it takes about 7 minutes four the fuel to become mixed when filling up.

Took a car with pump gas, pour in e85 and watched his flex fuel sensor for e85 to show up.

[stanlalee]

Its called backend as to not over signify what it really is...the primary tune (wouldn't want the free flash to sound more important than the device you paid $479 for). there is nothing back end about it. Its a flash tune like any other. As for recognition without flex sensor like Procede or factory flex fuel systems there is no recognition. There is reaction if the octane is not there and fuel trimming to the difference in stoic value of the fuel mixture but there is no recognition. If you have the desired e85 in the fuel tank and thru the lines on the first run (common sense would dictate driving several miles to burn off the pump gas in the fuel lines if you are adding ethanol to a tank of pump gas) then you shouldn't be getting any improvements after 10-15 miles (assuming the car is at operating temperature and your not using Map 5).