charosenz

I am running a Civic R18 off road racer with an aftermarket ECU (SDS). I am experiencing misfire, or possibly detonation when I go past 5000 rpm. I have the AFR at 12:1 and I have dropped the timing way down from 15 to 10 to even 6 BTDC but I still see it stumble as soon as it gets past 5000 rpm. It runs great up through 5000 RPM. Running 93 Octane gas.

I have ran a timing light to see if it was a bad coil, but all 4 of them show solid consistent spark and consistent timing.

Suggestions?



These are NGK 94290 which are one step cooler for when I hope to add a turbo.