Heat Management / Header Wrap (also for your turbo guys)

[PDenbigh]

I'm looking for facts and opinions on heat management techniques for exhaust systems. I have a turbo car that generates a notable amount of heat among the header, turbo, external wastegate, and 3" downpipe. I have had all of the components Jet Hot coated, and that decreased the levels of under hood heat by a notable amount but after 30 minutes on track it's toasty.

I would like to do something additional to the downpipe. It is 3" in diameter and about 2' of it is in the engine bay. As such, it provides a lot of surface area to dissipate heat into the engine bay.

My current idea is to wrap it with some header wrap. I have heard that this method causes the metal to deteriorate from the inside out, and other times it just casus cracks.

Anyone able to shed some light on this? From experience or otherwise?

Thanks a bunch!