gregsdart

Reason i ask is if they flow well, and the rest of the system is upgraded with long tube headers or an H pipe or both it might be a good sounding system that works well? Are the aftermarket h pipes bigger at the muffler, say 3 inch Vs 2 1/2?

The Ghost

Mufflers are really a sound only upgrade. Dyno results I have seen only show HP gains at very high RPM only and then it is minimal. The stock exhaust flows great with just about any mod you can put on the car short of supercharging. I can't remember the site name but one company was doing a series of dyno runs with different exhaust upgrades. Ultimatley they had JBL long tube headers, X-pipe, MAC mufflers. A very standard set up for most of us. They showed a 10hp gain at 5800 RPM but it only began to show at all above 4500rpm. To me thats a lot of money to invest for that little gain that deep in the power band. And the MAC mufflers made no difference in power at all, just sound.