Well, OP ... I drive my car like 200 miles per week with MANY MANY full-boost pulls each day. 93 Octane and zero problems and you can see the numbers I'm making.
Yes, E85 makes a great high-octane race fuel. It's an extra safety buffer as well. But you can take 93 quite a ways. P.S. 1/4 mile times have a TON to do with suspension, traction, transmission etc. Generally trap speed is a better indicator of actual power made.
1965 AC Cobra 427SC Replica [Carb Edelbrock 306ci SBF, 1980lbs]
2001 Mustang GT - [645WHP, 652TQ][MMR900 + Trick Flow Heads + Intake][ON3 Turbo @ 14psi]
2007 Jeep Grand Cherokee HEMI, 2006 Infiniti G35, 2012 Honda CRV EXL [The Daily Drivers!]