[myoung]

Just installed my Hotshot header (thanks Timbo!!!) do I need to put some header wrap, or wrap some of the wire harnesses since the heat shield is gone??

Nothing should be close enough to the header to cause any problems with heat... as for header wrap.....

search NPM ... Aug 04

I have heard it said that in addition to decreasing the underhood temperature, header wrap also increases the flow rate of exhaust gases. If this is true, could you please describe the mechanism that accomplishes this?
Barron Keith
Golden, CO

The idea behind header wrap is the heat will stay in the header improving the scavenging effect of the cylinders. Hotter exhaust gases flow more easily. The problem is it works so well at trapping the heat in the header, it doesn't allow the heat to dissipate and temps will increase beyond the exhaust gas temperatures (EGT's) the engine normally sees. This heating and cooling causes the header to fatigue and will most likely end up damaged, increasing your chances of buying a new one! Nascar and other racing teams used to use heat wrap until they realized any extra performance they may have seen wasn't worth replacing the header after each race. Heat wrap is more meant to protect wiring, fuel and oil lines, fans, etc. from heat.

 

[myoung]

No, The coating was metallic-looking. The header wrap caused it to turn a dull black. I wrapped all the way down to the flex pipe, and it all turned black.

Lew

But what would have happened in the long run? If it wasn't removed when you installed the turbo?.. There have been several instances of HS headers and others cracking that were wrapped. Not calling you old school (I"m old too...lol), but that's sort of old school... back when headers didn't have very good thermal coating or material that wouldn't disapate heat as well...

As Sarah mentions in that quote, even the NASCAR crews don't wrap headers any more.. They would know something about extreme heat on those 500 mile runs.. ....and thats a pair of massive V8 headers