I put the gmpp sport catback today. I am very happy with the sound. When i put the gmpp piping next to the oem piping it didnt look any bigger. Is the stock pipe the same size?

thanks

 

i think the gmpp is 2.25 n the stock is 2.0

im not sure if they make differernt sizes or what not

 

gmpp is 2.25, stock is 2.5 with a 2.25 portion over the rear bar.

 

So the aftermarket exhaust is smaller? Im guessing its the bends that make it more free flowing?

 

that is kind of odd. less bends do add slight performance of flow. however i would think if you DO go too big you just lose performance. i think they say if you have stage 2 or higher go to 2.75 stage 3 is 3.00 straight i THINK. but 2.50 is perfect size for stage 1 & 2 just on the stage 2 is when you upgrade the headers/dp. so even is your like damn why is it this small. just remember that the flow of the exhaust is more healthy for the car and your motor is much happier.

 

yes gmpp is smaller than stock, but the muffler is where you will get gains since our stock lunchbox mufflers are pretty restrictive. It would be a much better option to get a 2.5 inch catback and forget about gmpp.