i am trying to be as stock as possible so what does anyone think i should go for in piping. i want the car to have performance gains but i also don't my car to be loud at all. is 2.5 good performance wise but will the 3 incher be too loud with the gst muffler?

does the piping make the sound loud, or is it the muffler?

the gst inlet are 2.25, so if i get bigger pipes should the muffler dude cut out the inlets of the muffler at the rear to match the bigger pipes or do they we;d a flange to keep the 2.25 in wall of the muffler


-------jezreel

It's a combination of the piping and the muffler that creates the tone and loudness of the exhaust, mostly the muffler though. I suppose you *could* go with 3" piping, but the muffler shop will just flange it back down to 2.25" to match the GS-T muffler, which bottlenecks the whole exhaust, so it's really a waste.

I'll be doing this myself. Law's in my state don't allow ANY modification of the exhaust at all. I'll go from MY DP to the GST muffler with 3".
^^^ is correct on the bottle neck though. My thoughts are not to decrease it down to the stock size on the flange but on the GST muffler itself. This way I can put my tenzo venturi on when I go to the track and have a the benefit of the 3" exhaust without any restrictions.

i was thinking of cutting a larger diameter where the 2.25 inlet at the gst muffler is, maybe 2.75 or 3 inches.

-------jezreel

The largest bottlenecks on our exhaust is the cat. I just looked into the openings of our stock cats, and they are 2". I measured them. Also, the stock DP where it curves down, is also around 2" inside diameter. IMO, do a full 2.5" cat back, with 2.5" cat or testpipe. Then get a nice 2.5" inlet muffler. I have the Borla 3" inlet SS oval shaped muffler, and it sounds excellent. No buzz, no fart can sound, nice and deep tone. I'm also thinking of making any size test pipes you want, check out the PERF/ENG section for details.

Running a stock GST catback & muffler after going turbo KILLED my power.

I upgraded to a 2.5" Pacesetter, and welded on a set of Ractive dual tips (Part# T-564)

You can't tell the difference from stock, other than the Ractive logo on the tips. But power is easily 30hp more.