polished impeller/volute

[k6ng6r00]

Is there anything to be gained from polishing the impeller and the inside of the volute on a turbo/ centrifugal supercharger? It is still rough from casting on the inside of the impeller fins and inside the volute... cant imagine thats good for air velocity

[Redog]

Maybe Ion can chime in.

Personally, I think not much of a gain to really make much or noticalbe difference

[k6ng6r00]

I think im going to pass... i looked into maybe a polymer coating to smooth out&reduce coefficient of friction... could even probably get it done in the lab at school (im a plastic engineering student) but i would be afraid i would mess up the clearance for the impeller blade with a coating, or make it too big with a polishing.

[xXManwhoreXx]

I almost wonder if the casting helps grab air and move it or