Hello all. Figured I would post up here for any more pointers I could get from the knoledgable folks of this forum. I recently purchased an AEM viper from florida where the pump gas is 93 Octane. Now that I have it here in Oklahoma I can only get 91 Octane from the pump (unless I'm willing to drive well out of my way for every fill up)

My question is. How should I alter the fuel/timing map to allow for the lower Octane rating fuel without any detonantion issues? This is my first time tuning an AEM that isnt on a turbo car. Let alone a car without a knock sensor. Normally I would just dial back the timing, find the baseline knock value, and increase the timing agan until I started seeing detonation. Of course then back slightly off of that number and verify that AFR is still good through all loads and RPM. This car has a pretty good tune on it as it is. I dont want to have to start from scratch if I dont have to.