>>>*The theory on the increase in pipe size at the muffler exit is directional flow. A lot of mufflers are made that way, I have a 2 1/2" into 3" on my big old Chevy truck and she simply sings.

Plus we used to set up our stock cars the same way for racing and found a mile per hour or two on the straights regular as clockwork.

The stock pipe size is a bit too small on the 22RE's, but this can increase low end off idle torque, plus it helps keep things quiet.

Quiet is one of the factory's main goals, they spend as much money on sound as they do on power.

So expect to hear her a bit more with any mods. I happen to be about half deaf so that is a nice advantage....*LOL**...

You hope to head a nice whoosh sound or a steady even purr, then you have it close to right. If you hear popping and banging noises, loud unsteady sound, that is exhaust slipstream fighting itself, and that means you are losing power and economy..

I remember building the exhaust system on my old Nova, it was duals with two pipe size increases on both sides plus a balance tube. I didn't even bother with mufflers, didn't need them....*EB