Hey guys-

I have a custom made turbo manifold and a T3/TO4B turbo that I am putting into my 2000 Si. The guy who I ordered the manifold from said that I would not need to put a gasket in between the turbo and the manifold because these fail often. Has anyone had similar setups that could help me out? I don't know whether or not the add a gasket. It seems that most of the other parts involved (BOV, wastegate, etc.) have gaskets between them and their respective flanges. Any help would be cool.

Thanks.

 

hes correct. i never use one and never had a problem. as long as the surfaces are not warped they they should seal just fine and not leak as long as they are torqued down fine

 

The surfaces of the flanges would have to be 100% completely truely flat or you WILL get a leak. You can't really tell by the naked eye unless you take it to a machine shop and get them checked out. I would say use a gasket to be safe as it would most likely leak a little after a while. If you get a stainless gasket it would last you.

 

Any other suggestions?

 

Alot of custom kit guys like the no gasket approach. It can work, but you need to mirror the mating surfaces.

At the end of the day though, OEM manufactures always use gaskets, and at the end of the day a good gasket is better as it compensates for thermal expansion/contraction and maintains seal integrity. Soft copper is a good choice for exhaust gaskets.