Quoting matrixswan:
Aluminum has the advantage on the hot side of the turbo. Cuz it transfer's heat better than stainless. Stainless would be better on he cold side of he turbo and yes! Cuz it have better insulating properties than aluminum. But take I mind the aluminum is liter, and cheaper than stainless.
Well, now hang on a minute here....
Yes, the AL would be lighter, but by how much? Couple lbs maybe? You can use thinner walled stainless piping and wind up with the same strength and rigidity...Sooooo....50/50?
Don't forget that that AL hot side pipe is Bolted to, and crosses over, one of the Hottest parts of then whole shebang...So piping your air over extremely hot parts, and having it bolted to an extremely hot part isn't going to do you any favors. /ubbthreads/images/graemlins/wink.gif
By the same token, the Stainless might be a bit more resilient to the ambient heat in the bay, but it's still there, and fairly constant, so the piping is going to get hot too....Back to square one...
Stainless= prettier and pricier.
Al= a bit (if at all) lighter and cheaper.
Beyond that, the potential performance difference in that application is negligible, if not non-existent.
My $.02