Well, I have finally made the switch as of this evening from pump gas to E85!
First off, this stuff is awesome!.. 17* of timing at WOT with 0* of KR on my 3.5 pulley, so not too bad for starters. I am sure with different tunes, there will be more room to grow. Not to mention I have PLENTY of fueling room with my 60# injectors and just the ZZP fuel pump rewire on a new, stock fuel pump.
I also wanted to mention a few things about the tune. I did not change anything in my injector tables for this switch. While I know that would work, and likely be easier/simple to change, I went about it all with the Fuel and timing tables as briefly described below, just to see if it could be done successfully.
Fuel Tables:
1) Change stoich. target to 9.85
2) Change PE tables to target 7.3 at WOT (slight adders on that in the throttle position vs. AFR adder section)
3) Change Open Loop AFR targets to 9.85 as well (also change the Cat Over Temp AFR targets as well to 9.85 just to be safe)
Timing Tables:
1) Make sure you zero out the AFR Correction Spark Table. Doing this prevents the car from adding 8* of additional timing at all times when running E85
2) I also zeroed out the IAT Spark AFR table. Not fully necessary, but a good idea since E85 won't really require spark reduction at higher inlet air temps due to its intercooling effects.
3) Adjust the Main Spark Advance tables as best as you see fit depending on your application. For me, this was adding roughly 7 degrees to the entire right half of the table to start (and then making minor tweaks/interpolations in between to get a smooth timing map). I will be making tweaks to this as time goes on and I dial in the tune. But this should get you started if you want to duplicate.
Wideband values are showing good results. Stoich. values cruising around, and the equivalent of around 6.9-7.0 AFR when I get on the gas. I will likely bump my PE table up to target around 7.5-7.6 within the next few days as I am running on the rich side (6.9) even for E85. Again, not bad for a mild fuel system (minus the 60# injectors).
Time for a beer![]()