catback exhaust heat retention?

[auditude at get.net]

If we don't want our exhuast gas to lose heat and slow down in the pipe, would it be
beneficial to use some header wrap on the exhaust to keep the heat in?

Or, if that will cause a fire or something, maybe some type of coating to help retain
heat?

Granted these are esoteric options, but I'm just curious if they will help anything.
Maybe Eastwood Company or someplace like that has some type of treatment that
can be applied at home.

I believe the "quick rev" 2B downpipes are ceramic coated.

I have another question:  I know you can get mandrel bend sections from various
suppliers.  Can you get a tapered section, like for the downpipe "at" the turbo?

Graydon's downpipes are like the 2B ones in that regard, I believe.  I'm wondering
how they are made.  Split, squished at one end, and welded?

Thanks,

Ken