So, looking under my car I noticed that the stock downpipe pinches down to 2in at the O2 bung, and the pipe over the axel goes to 2 1/4. The whole exhaust system is in damn good shape.

Here's what I want some feedback on..

I figured I could probably buy a 2.5 DP that doesn't pinch down to 2in at the o2 bung, and buy a new muffler and bend a new pipe for over the axel so that it's 2.5 the entire way through, instead of paying 700 for a magnaflow, or 400 for the SLP and risk getting tickets for noise.

I figured that if I could pull this off, and be able to have a decent exhaust system for cheap, it might help out the folks here.

Any one have some advice, feedback, ideas and etc. before I begin this little project?

 

Very good idea done by alot of people on here.

 

just so you know the stock ss/sc downpipe is 2.75". i know it has its dimples and neckdowns, but for the most part it is 2.75". i don't know what mods you have, but i would go with a 3" downpipe over a 2.5" downpipe.

i replaced my stock muffler with a gmpp touring muffler, and replaced the 2.25" section over the axle. i felt a nice little bump in top end power by doing this. not to mention the lovely sound the touring muffler produces.

 

Thanks for the tip. My bro' works at a muffler shop, and said it was about 2in at the o2. I would only imagine that it restricts air flow pinching down to that much. I'll probably go with 3.0 though, if that's the case.

I currently don't have any mods. I just bought my SS/SC a couple weeks ago, and I'm just making future plans (once i get my financial aid =D)

 

well if you are stock. i would leave the stock downpipe on there. unless you plan on getting a smaller pulley, tune, and injectors, a 3" downpipe will be too large for a stock car. if you plan on doing the mods mentioned, go right ahead and get the 3" downpipe. then you will be ready for the future mods.

 

If your doing all that then you'll want to change the front of the cat back( the flange to the down pipe) that is only about 2 1/8" opening. Heres a link to the thred i made when i changed mine, crapy pics but you can see one or two layers of pipe at the opening mesuring 2 1/8"
https://www.cobaltss.net/forums/pictures-videos-64/new-cat-back-borla-175114/