exhaust manifold

I'm getting to the point where I'm about to pick up a big ported 16g evo turbo and I've done alot of supporting mods, my exhaust is going to be on next week and my fuel pump probably about the same time. I was wondering after reading a few sites about exhaust manifolds. Some say that the 2g exhaust manifold flows pretty well and doesn't really need to be upgraded to much. should i shell out the extra bucks and buy a new better flowing ehxaust manifold to install with the new turbo or should the stock one be good enough?


Also what vac should the car sit at in idle? I'm not to experienced with checking for boost leaks and what not. mine sits at about 20 normally, sometimes a little bit lower. but usually about 20.

The stock manifold will do fine. You really don't need it for a turbo. On a N/T car, it does have its bennefits. However with the turbo, even the larger ones, it won't make too much of a difference. If money is tight, don't do it. If you have plenty to spend, go for it. Again, not needed though. Good luck

It would like some porting though :) Just smooth it out a bit.

To answer your question about boost leaks, 20 vac is fine. Kevin mentions it here in his first reply:

http://www.automotiveforums.com/vbulletin/showthread.php?t=436825

Boost leaks make the vac closer to zero. I had a hole in the vac line going to my boost gauge and my car read 3 vac just for a related yet nearly pointless story :).

Stock Manny is fine. Port the 02 housing, or buy an Evo III 02 housing on ebay for $92 + Shipping

Question about the porting the O2 housing... does that only work for turbo engines? On the N/T the o2 is on the dp, and it seems like it wouldnt make a difference. Correct?

yep I bought a ported o2 housing from ebay. actually only cost me 74 dollars ;) it's ported out to 3 in or so I think.