I was helping a friend do work on a kids 95 gsr w/jrsc. My friend was doing headwork, p+p SC, and a mild build on it. When we disassembled the SC, we noticed the anti-friction coating on the impeller vanes was nearly all flaked off!!
We then wondered how it happened and if it was related to the hole in the side of the block from a broken rod. Also, the CAI filter had looked like it was original K+N from AEM. I know the clearance between the impeller vanes are tight and I wonder if dirt particles got past the nasty, rusted filter element and scratched the coating off. I was curious if anybody else has seen this.

p.s. When we completed the car the kid drove it back across state and raced a WS-6 and pulled a couple cars on the freeway.

 

you might find more replies to something like this in the FI forum.

i have heard of this problem of flaking before, although from what i remember people say its heat related and just peels off.

 

thats from the heat that the SC generates.