Originally posted by G32BTurbo
I've seen this stuff that you wrap around ur header and these header sleeve things. they say it reduces underhood temps and stuff. does this really work? does it produce some hp? is it good for turbo setups?
It keeps your exhaust from cooking everything under the hood. No horsepower gains directly... you MIGHT get 1hp from the intake tract being cooler or something. It's more for the purpose of the longevity of everything else under your hood that's plastic, rubber, etc.