I have a mach 1 mustang and i just want a good rumble to it.
Go to Youtube and do a search for MUSTANG EXHAUST and listen until you hear a system you like. Go from there. Everyone else will just tell you to buy what THEY like. There is no best and Supertraps suck.
An engine brake is a noisy device that helps large vehicles stop. It changes the engine timing to absorb negative torque and slow the vehicle. Some communities have restricted the use of them to keep the noise level down. Engine brakes are often called jake brakes.
I like Supertrapp. This muffler system goes on the back of the exhaust and has replaceable fiberglass inserts. Also is adjustable. Less end plates has more restriction and is quieter. More end plates the exhaust is more free and louder. Can be purchased in stainless steel too. Now for the answer I was going to use: The best exhaust system is very large pipes so that the bowties that got sucked in your intake don't get caught in the exhaust pipe!
For a 4V mustang (assuming you have an 03-04 Mach1) I prefer Borla or Magnaflow Magnapacks. I hate Flowmasters because they actually reduce performance by increasing backpressure to get their sound, so you might sound like every other mustang out there with flowmasters, but you'll be slower than every other stock Mach1 too.
