Ok, I just got back from the Muffler shop and had them change out my Magnaflow 10791 X-Pipe for the 12468 Tru-X Muffler. I am pleased to say I am very happy with the result. Around town it is just as loud and throaty. But on the highway the interior noise is greatly reduced.
A BIG unexpected bonus was an increase in Torque!! And I mean ALOT. The Supercharger kicks in faster and much harder. It is not my imagination either. I checked the dash gauge ( Iknow it's not very accurate) and it is really just as I feel it. I will get sound clips the weekend as I have the company camcorder. I talked to Magnaflow and they said the increase is due to the improved scavaging and back pressure of the perforated X-Pipe instead of the solid X-Pipe.
I know you used a Magnaflow system, Did it have a X pipe on the original kit and installing this new X pipe is different right? I wonder if that X pipe would make any difference in a GMPP/Borla system?
What do you think