i recently had a local speed-shop put all new bearings in my p1sc(bearings supplied from supercharger-rebuilds) because at an idol it made the infamous "grinding rocks" noise, turned out it had two bad bearings. i saw the bearings they were confirmed dead. after putting it back on the car it was still making the same exact noise however anything above an idol the noise goes away. so i made the shop take it back apart and they swear there is nothing wrong with it, their saying that some pro-chargers are just noisy. is there anyone out there smarter than me that can shed some light here?:shrug: