If I didn't see it with my own eyes ( and see it run 101mph in the 1/8 on a stock motor, with bolts-ons ) i wouldn't believe it. My friend with a GN isn't running any gaskets between his exhaust manifolds and his heads or O2 housing and turbo or manifold to turbo !!! He says as long as its flat on flat, he doesn't use gaskets there b/c they get so hot.. I'm not saying this is right, but it works !! I was reading about how to port the turbine sides and it said to only go as big as the gasket. Well, what if I don't use a gasket ?

I think I'm just gonna port the metal gaskets too, but what do you guys think...

Just get a bigger gasket.

You will most likely leak somewhere without them.

Actually all of the big names in turbocharging despise gaskets between ex mani/head, ex mani/turbine and turbine/discharge. Corkey Bell has quite a large chapter in his book detailing this, and Linginfelter has been quoted on many occasions saying that a gasket is only a bandaid for an inferior machining process.

The problem is the mating surfaces have to be perfect, a mirror immage of the part you are bolting them to. This machining process is VERY expensive and not very available. The best bet is just to use gaskets to "bandaid" the surfaces together for us mere mortals.

Actually, Bell doesn't "despise" gaskets (at least not visibly in print), and whilst they may be less than optimal, you have to remember that we're working with mass-market parts here, and that means we're not going to get "superior" machining on our parts, nor are they going to remain "superior" for the service life we expect from them.

One point Bell makes, and which I tend to agree with, is that SS gaskets reduce heat migration through the joint.

It's clear from even trivial inspection that the two-piece metal Mitsubishi head/exhaust manifold gasket is very effective. If it takes a bandaid to stop my exhaust from leaking, I'll wear it head unbowed. 8)

Originally posted by DrZiplok
If it takes a bandaid to stop my exhaust from leaking, I'll wear it head unbowed. 8)

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I'm right there with you buddy.

I'm not using any gaskets on my Mustang either. I thought that was insane when I was building it, so I called Cartech and they said not to. Its never had a leak. The header flanges are 3/4" so they resist and warpage and seal tight. The twin turbo system was designed by Corky Bell. I'm not sure if Cartech is affiliated with Bell Engineering anymore, but I wish They would make parts for DSM. Hi quality stuff.
My GSX on the other hand leaks something awful. I haven't had time to fix it and its driving me insane. I'm pretty sure its leaking at the head/manifold, but all the nuts are tight to spec. . Damn gaskets.