ok i rechecked my supercharger and the guy didnt sell me a faulty unit. the shop took out bolts to the supercharger and it was comming apart i cant belive they did this. i fixed it it works fine now. the only problem im having is i have the timeing at 10 and when i rev the engine up it revs up slowly and my cars runs really slow also when i try to rev it past 4000 rpms it stops and backfires. what can cause this to happen???