Louis53123

whats going on, i got an LS VTEC Turbo build and im still thinkin about what kinda exhaust I want. I have a t3/t4 58 trim turbo with a 3in downpipe. If i were to make it go from 3in downpipe to lets say the axle back, then down to a 2.5in just to make things quite, would it affect my performance alot? What about having a 2.5 inch exhaust overall with no cats? im going to be running about 10psi daily, i know about maniflow makes a nice 2.5 inch, Apexi World, and thermal makes a quite 3 inch...again im lookin more for quiteness but at the same time performance..anything will help

DJ Gurgla GSR

if your DP is 3 inches then don't choke it off with a smaller cat & exhaust. go 3 inch all the way.

OR if you go with a 2.5 inch DP, then the smaller exhaust could be an option. but you'll still lose some performance. You're better off getting a full 3 inch all the way

blackeg

or run a cutout. 3" cutout at the end of the downpipe would be cool, and you can run stock catback to keep the cops away

Louis53123

DJ Gurgla GSR, good point about choking the exhaust going from a 3in to a 2.5

blackeg you have a good point, i have a WRX as a daily driver and i have a QTP cutout with is the 3inch cut off, and its not a bad idea about have that, im really conseriding doing that again. Then getting a quiet catback with a hiflow cat for ab 200 bucks or so....

Paul W

A 3in downpipe with a smaller exhaust will make less power then a 2.5 dp with 2.5 exhaust.. better to be as close to the same diameter