E85 is good stuff. However I don’t suggest running pump e85 on the bikes without a standalone ecu with a flex fuel sensor.
E85 is mixed on site at the gas station. So ethanol content varies significantly from station to station. Around Houston I usually see anywhere from 63-75% ethanol. Every once and awhile I’ll get 85-90% from the same station by my house.
I haven’t tried tuning a bone stock Busa on e85, but I feel the gains might be mute. On a high compression 1403 all motor Busa I did we picked up 18whp going from vp110 to vp c85. It’s a track bike only.