I was thinking that because the header on my VE is so close to the radiator that it might be causing it to run a bit hotter than it could. Has anyone tryed that exaust heat wrap stuff on their headers and/or Y pipe? It seems like a good idea to reduce the temp under the hood.

 

with the wind blowing through the radiator while driving there probably wouldn't be any chance of the manifold heating the radiator that much if at all. the only time you would have to worry about that is when sitting still but when sitting still you actually have to worry about no air going to through the radiator to cool the coolant down. so, the fans do that for you.

wrapping the manifolds might decrease underhood temps pretty well but wrapping them is supposed to decrease their life span.

 

Why would it decrease life span?

 

Heat fatigues the metal.

 

Lets not forget that the existing manifolds already have a form of heat shielding already on them.