These are the points that keep me “off” the E85 bandwagon.
Some of the Turbo Ford guys in the midwest where E85 is really cheaper have done the conversion by just upping injector size by 30%, no tune, playing with fuel pressure to dial it in, and running it as a daily driver fuel driver. Seems to work for them.
The other camp is the guys using it instead of race gas. They seem to be the ones picking up in the inconsistancy of the E85 blend (and having tuning issues), especially in cooler months where they add more gas to “E85” becasue of the cold start issues.
The best of both worlds seems to be a system (like megasquirt) that will accept the input from the mixture sensors used on some of the E85 capable cars to really tune based on real mixture. Those are still too costly to experiment with, so it might be a few years off before it gets worked out.
I too have seem some amazing reports of E85 conversion instead of race gas, but also know of two turbo cars that had big issues (one blow through carbed, one EFI) because of the incosistancy of the fuel.
Bob Myers