I have a 2000 Gt and want to know whats the power gains from stock to a Hi flow catted x-pipe like Bassani or Magnaflow. I hav a Borla catback and C.A.I. and 75mm throttle body.
With what little mods you have, I'de say a catted X-pipe will only yield around 6-8rwhp in itself. If you get the one from Bassani, it might yield a few more ponies, because it is a true x design. Don't know if the Maganflow x is a true x or a stamped design.
Another advantage is gas mileage. After I installed my Bassani catted X, I got 20-25 more miles per tank of gas. Engine is breathing a little easier now.
I have the Borla Stinger cat-back mated to a Magnaflow X and the sound is incredible. Not too loud but just right.. You will love it.. As for performance, I didnt do a be4 and after dyno but I did feel a touch more SOTP pull in the 4-6K rpm range.
I'll have to look for it - it's laying around here somewhere. The 'after' dyno was done at a different place than the previous one, so that may account for a slightly lower reading, but the 6-8rwhp stated by Dark Knight is probably about right.