The fuel curve can drastically change as the boost goes up.... We like to tune for good safe power at the max someone will run....He likes to run the high boost and race gas on the street..... The safety factor on 91 octane is to turn the boost way down and not push the car on 91 gas. 91 sucks and you can't get much power from it.
Quite a few of us run race gas most of the time here in Ca.... You have to pay if you want to play.....It makes a whole lot more since to me then tearing up a motor trying to get the most out of inconsistent junk 91 fuel.
