Why is your motor knocking on 93 and 94 octane? Is your timing too advanced? Higher than stock compression? Or lack of tuning.

I assume you are using leaded 110 race fuel, this will contaminate the sensor quickly, you might delay it a bit by doing the mix you are talking about - but you shouldn't need 110 anyways unless you are running 12 to 1 compression or boost.

BTW, is this Canuck R by any chance