scca sm

i have a 1995 cobra with a kenne bell running 6 pounds boost. i just got it dyno tuned because i had detonation and couldn't get above 4 thousand before it sounded like it would blow up. after my tune i found out that after 5 thousand rpm it shook like it was giung to rip the motor out of my car. i just had a centerforce dfx clutch put in and a new light fly wheel at the same time. the vibration got worse. today i got a new harmonic dampener put in and it got better but its less of a shake and more of a buzz that can be felt through the seat. I'm lost. any ideas would be greatly appreciated.

Portmaster

You may have busted a Piston skirt off. The new balancer may just be asorbing more of the vibration than the old one. I'd be tearing that thing down and ckeck it out before you ruin the rotating assembly.

Timspony

Something is out of balance with the rotating system...is it possible that it could be the driveshaft or u-joint? Aftermarket bellhousing?

FORD TOUGH

Something could be rubbing and causing a vibration also.

woodsy

Does the flywheel have a bolt on counterweight and is it the larger 50oz weight, I have run into plenty of guys that buy a flywheel with the small 28oz weight installed instead of the needed 50oz weight.

scca sm

when i first got the car it had no cats. i took it in to get the original cats put on. after i got out about a mile away i tried to take it to the red line on the floor and it backfired so bad it shut off the engine. ever since then the hood has been getting a black spot above the supercharger and the supercharger has been leaking oil.