Exhaust sound

[Scott 02]

just wondering why when i hit the gas kind of hard there seems to be hardly any sound out the back of my car. When i'm at 2000 rpm's its loud as shit, but about 3000 its not. My car is the only one I have heard that is quieter as rpm's rise thany any other car wheather it has duels or a single pipe going into a muffler and coming out in two. I'm guessing that the fact my car is FWD and the way that motor is position with the front header in the front wraping around the motor makes this happen. Would taking the CAT and U-bend out help this? Everything else i did to my exhaust is custom and its as loud as it gets.

[JoeJoe231455]

Most gtp exhaust have this issue...and I believe it is due to the bypass valve.

If your running around cruising at 2000rpms or so the bypass valve is open, turning your boosted gtp engine into an 8.5 to 1 slug 140hp motor. This of course is great for the highway mileage. The exhaust outlet temps are also much lower at this time because your engine isn't being boosted, and it is weak as hell. The second you get into the throttle, the bypass closes, the boost begins...the exhaust temps soar and all that piping is being put to good use. Very hot exhaust gas needs alot more pipe space than the stuff coming out during a cruise. So it fills the pipe up nicely and there is less exhaust gas just bouncing around in the system, causing all that drone and noise in the lower rpms.

I am running a 3.25 with a bunch of nice supporting mods, and friends cruising behind me when I ram the throttle have told me they can "hear the supercharger" from my exhaust. Meaning...they hear a loud rush of air coming out the pipes which is fairly quiet compared to the cruising sound which is a deep gurgling drone.

[Scott 02]

Yeah, but the GTP's sound the same as the GT's at those rpm's> Maybe its just how those 3.8 series II sound.