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HondaDustR HondaDustR is offline
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Join Date: Jan 2007
Posts: 2,439
Yeah, I was in the throes of an exhaust project a few weeks ago...the short answer to a good sound is do not remove or gut the OEM cat. It's the only thing that will block the rasp and alot of the resonance. I bought a 2.25" in/out Thrush welded muffler to add on to my system with a gutted cat. Nice sound but a little too loud, WAY too much low frequency resonance at speeds below 3K rpm, and a bit of a rasp. Big glasspack in place of the cat sounded like *****, stock muffler with big glasspack in place of the cat sounded like quiet *****. Thrush welded with intact OEM cat sounds freaking awesome and is easily tolerable for daily driving (and it passed emissions). Nice deep throaty hollow flowmaster type sound with no extra BS. I have to make a video of it in its current form. I think one of the baffles has detatched inside a few days ago and it doesn't quite sound right but it was only $40 and I could probably get a new one under waranty. Here's a vid of the failed parts of the project (before the cat).
YouTube - Porsche 924S Thrush exhaust project

Keep in mind, the larger the exit pipe, the louder it will sound, and probably the more resonance you'll get. That strong low frequency sound will kill your hearing over time as well as give you a headache.
1987 silver 924S made it to 225k mi! Sent to the big garage in the sky

Last edited by HondaDustR; 07-07-2010 at 06:35 PM..
Old 07-07-2010, 06:25 PM
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