Ok I have a redtop sr20det that has a bad exhaust leak. It sounds like it is coming from the no. 3 or 4 cylinder area. I took the manifold off from the block and the gasket looks ok and I couldn't see anything wrong with the manifold it self. I'm pretty sure that it is pre-turbo, the turbo isn't spooling up like it is supposed to but it does go from vacuum to a couple of pounds of boost. Does anyone have any idea of where to look next?

 

check the flange gasket in between the turbo and manifold. if it is that gasket replace it with a copper t2 gasket like from a TT 300z. If you have a cheap ebay manifold, looks for cracks in the manifold.

 

+1 cracks on the manifold suck. had to rebuild half my mani with thicker steel and made support brackets everywhere. it weighs like 10 lbs more

 

I've got an XSpower mani so it's not the best but I didn't see or feel any cracks in it. I'll have to check out that flange gasket. Thanks and keep the idea coming.