Bunch of guys on the bullet run pretty fat.

E85 tuning with efi and boost - Yellow Bullet Forums

Let me know if you go on the 3rd, I'm off that weekend I'll make it to there.

I have played around a bit with my truck. I settled around 11.5. Couldn't gain anything by going richer, other then running out of injector sooner. There is a local ricer shop (i know, i know, but their tuner is actually VERY good, and they do some LS and mustang stuff too)that specializes in e85 I guess you could say. I talked with him about it for awhile, he said e85 is actually a little more forgiving to being a little lean vs gasoline. I am only running 13-14psi right now with injectors at 110% with meth. Thinking about going larger and 17-18 psi.

I run stoich at 10.0 (I don't have lean out cruise and want better mileage ) and command 7.4 at wot.

Haven't had it on the dyno yet to see if it makes more power by changing around Afr but the butt dyno likes 7.4

I'm with Joey, 11.5 on the gas scale. I've been messing with E85 for 6-7 year nows. That said, you really can go either way from there a full point without issue, but once I start getting into the 12's I'm adding fuel or turning down the boost till I have more fuel. Going the other direction, to deep into the 10's you will start to stumble due to light off issues.

around 6.5-6.8 on the e85 scale i started having the stumble you described