E85 and ethanol

[fueler]

I have a '02 GMC Sierra 5.3L. If running E85, will I need to configure anything differently than the settings already there for the 93 octane tune? The pump says 105 octane for the E85. The car was not marketed as the flexfuel version, but I have been told that it will run on ethanol as long as fuel parameters are set accordingly. If I'm correct, I will need an increase in fuel (maybe along the lines of 30%??) and might be able to advance timing a bit more to take advantage of higher octane?? Anyone running E85 with their Predator?

[johan]

Well they made some e85 5.3L's in 02, if yours is one it should display a "Z" as the 8th digit for the vin. If it does you do not need to do anything, the tuning for e85 is already in the pcm.

[fueler]

Mine was not one of the models sold as "flexfuel" - I'm told that the programming is the main difference in the flex and standard models. I would like to run E85 and eventually E100 - I have a fuel ethanol license and would like to make my truck scream on American Made Energy. There are particular products such as the Fullflex Gold and the Flextek that are sold to allow any fuel injected car to run on any blend of gas/ethanol. I think that they must make their changes based on O2 sensor data?
Anyway, I think that I could promote alternative fuels best at the track, where people have been running alcohol and methanol for years. If only they could tweak their cars and trucks with the Predator to take advantage of this clean burning, renewable, high octane fuel... I'm willing to be the guinea pig and try it out, but could use some guidance as to whether my Predator will do it in "standard" 93 octane predator tune or can I make the necessary adjustments to make it a go?

[johan]

I am not 100% sure what tells the pcm to switch to the E85 tables.
The pcm in your truck has separate timing tables for E85 fuel which it would use, we do not alter those in the regular diablo tunes. You truck should run fine with the regular diablo tunes and e85, but as i said before the timing would remain the stock e85 timing.
I have not looked into the fueling calibration based on e85 so i am not sure how it works.
Before i would try anything i would verify that your 8th digit vin has a "Z" in it, as this denotes the flex fuel motor.