I know one bottleneck. That is where the cat connects to the exhaust B-pipe. Are there more? In the muffler?

 

There are two bottleneck points in the OEM catback. One, as you mentioned, is near the cat. The other I believe is in the axle-back portion. I think there are three.


[Modified by TypeRJason, 8:01 AM 6/28/2001]

 

In all there are 3 bottlenecks in the OE B-pipe and axleback. The first is the one you mentioned at the cat/B-pipe connection. The second is at the B-pipe/axle-back connection point. The third is as the axle-back enters the can!
Dave of SMS can probably give you specific I.D. numbers if your interested.

 

Do you think it will help a bit when I remove one (cat back) bottleneck together with a big test-pipe? Or do you think I should replace the muffler and the 2 bottlenecks in the B-pipe.

 

Eliminating bottlenecks are always good, but ultimately your set-up should dictate your actions. I have Spec B's and decided to mod by B-pipe by cutting it after the first resonator and installing some 2.5" piping instead. This set-up is still choking me out in the upper rpms so I have decided to build a completely new 2.5" exhaust. If your not looking at aggressive cams, the eliminating the first bottle-neck should be fine or just invest in a 60mm aftermarket cat-back.

 

I still have the stock cams. I'll try this first. See if it helps.

 

Thanks for clarifying