well we know what wrapping does...

that heat stays inside the exhaust, where its SUPPOSED to be. If your exhaust components deteriorate due to the heat staying INSIDE the exhaust... it sounds to me like there is a problem w/ the material that the exhaust is made of.

Its better to keep the heat inside cuz the exhast can flow better. when it cools, it becomes denser and harder to push out the pipe. the exhaust isnt a heatsink... its not designed to radiate heat. if it was, they would have engineered fins into the pipe along time ago. there is no benefit to allowing the heat to escape the exhaust while its inside the pipe, tube or manifold.

all that does is make the exhaust colder and denser and harder to push out the exhaust, heats up your engine bay and causes your wire harness plugs to get brittle and break, youre coolant hoses to get brittle and rupture (Z32 anyone?) makes your IAT higher than it has to be... just not good...