I have a 408 that I will spraying. I believe when the tune was done it took 23% more fuel to compensate for the lack of thermal energy in e85 compared to gasoline. I have 60lb injectors to keep up with the increased fuel demand. I also have a stand alone fuel system. In the stand alone I will run 116 octane race gas. I could run e85 which is 110 octane, but for max power I'll run 116 octane. The e85 has a slower burn to help with detonation and also because of the alcohol the motor runs cooler. My motor is 13.5 compression with no knock no matter how much timing I run. I've had 35 degree's of timing no problem.