Exhaust Wrap - Insulator or Cooler?

As I understood it, the wrap keeps the exhaust gases hotter so that they would evacuate the pipes faster. Moving heat away from the engine faster and allowing it to work more efficiently?

As far as rusting the pipes, another member posted that he had pulled the wrap off of his pipes after five years and the pipes were cherry. He stressed useing proper sealant-spray, though. Proper seal= no trapped condensation?

I use it on the Supertrapp 2-1 on my Harley Fatboy in a 7 inch spot on the collector so it dont melt the heels on my shoes. That works good, as far as any other benefits I doubt it. The 4-1 pipes on my KZs & GS bikes dont come anywhere near anything so I see no need for it. If it does anything power wise its not something you'll see or feel in my opinion.

bountyhunter wrote: Bike engines are so finely tuned on intake and exhaust that changing one knob without any other change usually causes a LOSS of horsepower.

Oh if I only had an hour every time I had to relearn THAT again.