Maybe I'll have better luck in the turbo forum :)

Looking for some input on how to make a quiet 3" exhaust system. I have found a couple mufflers that have a 3" inlet and dual 2.5" or 2.25" outlets. Do you think this would be quieter than a straight 3" in/out? I had a VRS 3" with long resonator and a 3" in and out Magnoflow straight through muffler and it was pretty loud with a test pipe. I'm looking for something quieter this time around. Maybe I'll have to go with a 2.5" instead. If anyone knows of any dyno numbers with the same setup except showing 2.5" vs. 3" please let me know. I've seen some sick fast DSMs that run 2.5" so it might not be too bad.

http://www.imagestation.com/picture/sraid43/p824bbfb4562e1fe7d701781964eb707a/fce84294.jpg

I believe it's a universal can. It has a 3" in and dual 2.5" outs. When I had the bluebird motor, I was using 2.25" downpipe to cat. I had a resonator in place of the cat. 3" cat back with another resonator before the can. I thought it wasn't that loud...no droning anyway. But it can get annoying on long trips.

I have since dyna-matted the trunk.

Jody

this is my setup i have a 2 1/2 inch down pipe and 3 inch pipe straight back to my hks 3 inch inlet muffler and its reaally quiet a real sleeper lol

then check out the dsm guys and run what they run
tons of useful threads on dsmtalk and dsmtuners

I have a 2.5inch downpipe hollowed cat and 3inch to a Apexi N1 exhaust....all I have to say is that my car sounds HARD but its pretty loud...I used to have a cherry bomb as a resonator it was VERY quiet...but I don't know for sure...Pretty much 3 inch will be loud I don't think there is anyway around it...

Magnaflow, or someone else, makes a 3" ID muffler/resonator which I would use before the muffler. You might even be able to fit two on their if you're really crazy about trying to get the car quiet. And Dynamat does wonders. I used 3 rolls in my trunk which really quieted it down. I think I went around 5 layers thick right above the muffler in the trunk.

Daves Magical Asspipes worked for me.