who does 2.5
 

whats a good 2.5 lsj cat back and down pipe i really like the zzp one but they dont have a 2.5 cat back idk why? i dont want megen and i would love corsa but way to expensive and no custum

I'm not one to normally say this but use the Search button. You will find TONS of info of catbacks.

Catback is really only for sound on our cars. minimal gain if anything. But if you just want the sound, your choice. if you want power... choose another part

nothing wrong with the stock catback or the stock ex manifold read and learn

https://www.cobaltss.net/forums/dyno...5-dyno-246633/

I agree big power has been made with just the stock exhaust. But I would say a catback isnt just for sound. Remember back in the day JonyyB doing a before and after with stock and GMPP exhaust? He made 12hp with the GMPP. And it's a smaller diameter than stock. Go figure haha. Oh I found the thread.

https://www.cobaltss.net/forums/show...P+exhaust+dyno

hmmmm, wonder if this still holds true for once you start making 100+ more hp than stock or if it becomes a restriction? ( GMPP exhaust )

There are restrictions in the stock catback that most don't know about....

The inlet to the resonator is only 2 1/16" i.d. & the muffler is not a straight through design.

That's why people gain "some" horsepower from catbacks on the SS/SC.

The SS/TC has a very good catback from the factory:

- 2.75" inlet to the resonator
- full 2.5" piping
- straight through design muffler

Apparently not haha

https://www.cobaltss.net/forums/showthread.php?t=246633&highlight=Wsfrazier

If 2.5" is all you're looking for, I highly recommend the GMPP Touring exhaust. It's a COMPLETE change in the exhaust note. Low, smooth, purr.

GMPP isnt 2.5". It's 2.25". But I agree on the sound.

Too bad the LNF muffler sounds like ass on a LSJ.

good catch.

I think it has to do more with the tiny resonator that comes on the SS/TC catback.

You have a full SS/TC catback on your car don't you Eric?

Maybe a larger resonator would help.

Is there a way to just buy the gmpp muffler and tip? then ill just have 2.5 piping bent.

I have a magnaflow cat back. I think it sounds alright. I rather have stock though. Loud cars are annoying to me.

ugh, i used to have a magnaflow catback, then the piece of crap broke off clean where the piping goes into the muffler

http://i50.photobucket.com/albums/f3...xhaustLeak.jpg

http://i50.photobucket.com/albums/f3...h_102_0699.jpg

http://i50.photobucket.com/albums/f3...h_102_0697.jpg

http://i50.photobucket.com/albums/f3...t/102_0696.jpg

i have a custom magnaflow setup with a 22 in glasspack

LOVE it!!! except when its cold it sounds like a honda cause im catless lol

This is what i'm gonna consider doing in the spring to make my exhaust sound a bit better. I have a 14" magnaflow resonator but it does jack squat IMO. A lot of people say the glasspack will burnout though?

whatever was in hahns exhaust if i had a car behind me it would always look as if it was snowing. something was coming out of it.

so the gmpp cat back i also need a down pipe due to a cracked flex pipe iam looking at the zzp 2.5 catted will that match up with that gmpp what other good DP's are out there

ZZP makes the best dp by far.

I had one made at my local tuneing shop. Had it that day and was cheaper than online. Nothing wrong with ordering from any of the vendors here tho

My first exhaust setup was just that....

I found a guy selling just a muffler from the GMPP touring catback.

I had it welded on to the stock catback, and it sounded great!

I still like my Corsa setup better though.

Agreed!

Agreed, but if you're going that far, I recommend their Header/DP combo. By far the best top end gains you'll see from anybody.

well i ant really looking for hp gains i want a good sound i need a down pipe 2.5 form zzp and a 2.5 cat back but i dont have a clue where to get one corsa is to much along with the gmpp i think iam better off going costum