In Reply to: Re:What did the factory use on non-cat??? posted by Doug on March 01, 2001 at 16:19:08:
The earlier euro cars had a resonator and 200hp. The EvoII had a resonator and 220hp.
There is a pattern here: Resonator makes about 5hp more than the cat. I believe this is because the resonator has the crossovers for the proper tuning of the pipe lengths while producing less back-pressure than the cats. Straight pipes have less power than the cats because of incorrect tuning of the exhaust.
So, you can go with a stock or aftermarket resonator and you will likely gain a few hp. It will, of course, be illegal for the road and bad for the environment. Whatever you do, don't just cut up your exhaust. You'll likely lose power.
I guess what I'd like to know is what the factory used instead of a catalytic converter for the European version w/215hp.