Vibration cause?!?!?!

vntned said
No detonation that I can hear. I ALWAYS run 93octane fuel, and I drive it a couple times a week, 50-100miles maybe.

Yeah I would think that would be plenty with a 9.3:1 static. I had to pull a couple degrees out of mine at the top but I’m at 9.8:1 and can only get 91 octane.

What balancer are you running? Might not hurt to try a different one...