Hello, I’m building a 22r and planning to go with a higher compression ratio (12 to 1) and was wondering what octane ratings I need for that much of a compression? We only have pump gas available (91) but I found race fuel concentrate that I can mix to bring it up to 100-105 octane. Will this be enough?

 

Is this for a street engine or race?
I'd start with 91 and play with the timing and see if it pings.

 

Yes it is used in the streets but barely, it will mostly be used for drags. As of right now I use 10.5 to 1 compression ratio with 91 octane and it does ping at times so I dialed back timing. Was thinking to use that race gas concentrate to build a 12 to 1 stroker build or else I’m just gonna have to use a 10 to 1 stroker motor.