When I had my Celica the Forum I used to visit had an awesome sticky where members posted Manufactures information on different exhausts and personal dyno results. Also members added pictures of there own setups and sound clips. Most of the clips were of the car revving and holding at different RPMs. Some of the guys with good equipment posted sound clips of the exhausts while the car was driving.

Example:

Brand X exhaust

Manufactures estimated HP gain:
Dyno results:
Sound clip:
Post Pic:

Other info:

As soon as I get my exhaust I will post all my info and sound clips. Right now I am really struggling between waiting to hear and see GReddy True duel or get the Borla now! I hope other members will also help out buy posting sound clips and reviews if they can.

 

Well, we have a sticky that has the list of almost every modification part. You have to do some searching, right now the forum is screwed up so I can understand why you are asking. You have to go through about 3, maybe 4 pages to find what you are looking for. Most people don't have dyno's, but some have sound clips, a lot have pictures, and most have review's. It just takes a little looking.