I need to replace my turbo manifold gaskets and was wondering if there was any benefit or downfall to smearing copper rtv on the stock MLS manifold gaskets. Ive seen people do it both ways but I figured the RTV was only for mating surfaces that didnt have gaskets

 

I would replace the gasket.... but for a temp fix you could use it.... ( but it would be double the work?!?!)

 

^^ + 100 What he said.

 

i plan on replacing it, i was talking about putting the rtv on new gaskets

 

If you are replacing the gasket, no need for sealant.

 

I think copper sealent may have been used on the motor Cas007 originally bought. I don't think his mechanic/tech liked it. But it looks like whoever applied it got it everywhere, even on the pistons (unless it was a copper colored ceramic coating on the pistons, which I doubt, because my pistons are ceramic coated and do not look like his did).

 

Hmm..I have seen cooper spray used on head gaskets before. The domestic guys love that stuff, and some of the Evo 4G63 people use it to. I havent used it before on the VQ35. I imagine it didn't hurt anything, however.

 

That is also a spray and not the same thing as copper rtv. Copper RTV is in a tube like regular silicone and works well on exhausts. I used to deal with circle track race cars and we often had problems with the headers not sealing on ported heads and would coat the gaskets with copper rtv before installing. It's a little messy but adds an extra level of sealing.

 

I sprayed the gasket with the copper spray on my built 4G63 it held the head gasket with 30psi on my 60-1.

My entire exahust system except for the manifold to head was all Copper RTV. So Manifold to turbo, turbo to downpipe etc etc..

You can use RTV on an old gasket if you are concerned but a new exhaust manifold gasket will not need it. You could use RTV for the head to manifold without a gasket but it's messy and wouldn't look very nice and would stain the aluminum of the head. So use a gasket there, RTV everywhere else.

One thing to know is most exhaust systems are designed to use a gasket so if you start eliminating them you will be taking a bit of space away and could cause the exhaust to move enough to bang on stuff, so just be aware of that. Generally RTV is a much better gasket on a turbo exhaust system than a gasket is, it will never blow out.