Quote Originally Posted by nofive-0
If I assume your engine is fairly stock straight pipes will not be much difference in power than with a resonator.

Yes it is true in N/A applications a little backpressure is good. Really the most important thing for an exhaust is the exhaust gas scavenging ability. That is basically all in the header, and doesn't have that much to do with afterwords.

My advice to you is to come off the header where it bolts to the cat. just use some 2.5" or 2.25" tubing for a foot or so. Im pretty sure on efs the 02 sensor is in the header so you shouldn't have to worry about that. On the end of that first piece put some kind of resonator, then a turn down on the end of that. It really shouldn't take more than an hour.
I'll probably follow your advice. On EF's, the O2 sensor is located on the header. However, the LS motor (obd1) is built with the o2 sensor being in the downpipe.

Currently, yes, the engine is stock. In time, however, it will be built. If I build NA, my goal is 200 at the wheels. If I build turbo, my goal is 300 (give or take) at the wheels.