Well, if I remember from the past, the top 3 Loudest full cat back exhaust systems, are Thermal (forgot which), Tanabe Racing Medallion, then the Apexi N1. The Tanabe was like 1 decibal louder than the Apexi. I had the N1 and it was loud. I lost a good amount of the loudness with the silencer, but then I didn't like the silencer on (it looked dumb with the silencer on IMO). I Now have the Greddy Evo, and it is way quieter than my old N1. I haven't gotten pulled over with the Evo yet. Had the exhaust for over a year now. Have you thought about the twinloop or rsr-ex mag?