For those of you running ESP with turbobacks and no boost controller, are you concerned about 22+ psi boost spikes and pump gas? Not sure whether I ought to run race gas for autocross events to be safe, or whether timing needs to be retarded in the mid-RPM range to be safe. Or is the factory knock sensor/ECU quick enough to take care of any detonation issues?

 

I ran my car with 94 octane all the time. My boost would spike up closer to 24 psi and I never had a problem. I was worried initially too though.