Question on dimensions for exhaust

[kverges]

I am thinking about building new tubing from the stock ('01) header collector to the CORSA cat back system, all in 3". I can get the armored stainless flex piece and stainless tubing, but I did not know the dimension and source for the flange that mates to the header collector. I could take it apart and go on a scavenger hunt, but I was hoping someone else could tell me exactly how big it is and where to get the flange parts.

Thanks

 

[GTS Dean]

Henry Cone made a very informative post on this very subject recently. I think it was in the Performance Mods area.

 

[Henry Cone]

Keith, unfortunately the exhaust manifold collector mates to the primary pipe (that has the flex joint in it) with a rather unique flange and clamp set up. Basically each piece has a round flange on it. The 2 flanges are clamped together with a special clamp that has an inverted V cross section so that when the clamp is tightened the 2 flanges are pulled tightly together.

Also of importance to note is that the manifold outlet and the primary pipe are approximately 2.5" in diameter. So the flanges become a problem if you are trying to run a 3" exhaust. It would require reworking the manifold with a completely different flange to eliminate this bottleneck.

My suggestion would be to do as we did - use the stock primary pipe up to the stock catalytic converter but replace the cats with hi flo ones. Doing this picked up 17 HP and 23 LBFT on my car. We got a set of primary pipes that were take offs that already had the cats removed so that we could save the original exhaust system. Archer Racing and JonB both have take off primary pipes..

I hope that this helps. Feel free to contact me for further info...