it traps moisture under it, so yes eventually it can cause the header or whatever you decide to use it on to rust and possibly crack...

 

i use it on the turbo manifold. it keeps the temp lower but im not to sure about any performance gains from it

 

What i herd was that it would crack your headers and somtimes with you take off the wrap your header would have cracks in it.. just my 02 cent.. i would never use it...

 

Like previously said, it traps moisture as well as the heat. This causes the exhaust manifold/turbo/header(s) to rust pre-maturely. If you pay close attention, many header manufacturers will actually give a disclaimer saying header wrap will void their warranty.

I personally would never use it. If you're looking to lower your engine bay temps, I would much rather just get a vented hood to allow the heat to escape. I have read studies done where header wrap actually cause a loss in hp, and premature exhaust valve wear(think about thermal transfer, metal usually being a great conductor of heat, heat rises, and low and behold most exhaust manifolds/headers are routed downwards). I'll try to find that study.

As far as the theory of header wrap... it's something along the lines of trapping the heat in to the piping (hot air travels faster than cold air). The catch that isn't talked about aside from stated above is it has to be matched with the proper size tubing.

EDIT (clarification)- So despite the exhaust gases exiting the system quicker, the piping itself will retain more heat which works its way up to the exhaust ports.

 

woudl having ceramic coated headers do about the same as wrap with out all of the down sides from ^^^

 

A vented hood isnt going to give you nearly the same benefit as some form of heat retaining material on exhaust piping.

Ceramic coating helps, yes. As much as wrap? Im not sure as Ive never seen a comparison of the two. But there are people that swear by it just as there are people that swear by heat wrap. Ive never heard of people having problems with it, but the downside is it costs more than wrap.

 

you cant compare it with ceramic coating. WHen you get something Procoated they teflon coat the inside and ceramic coat the outside, and it drops the temps dramaticly, and also loooks waaaaaaaaaaaaaaaay better.

header wrap is garbage.....unless you dont want to spend the money on having it coated

 

ceramic coating is kinda exspensive, but it does last longer, and i agree it does look better!

 

depends on where you get it from ....and i got the hook up =)

 

tru, i need to do one or the other on mine, pm me a price on getting it coated