Anyone have real world experience, dyno numbers, or track times comparing the stock exhaust and air box to the GM Performance catback and cone filter intake (see link for more details)?

http://www.chevrolet.com/cobalt/accessories/

Whats the difference between the touring and performance catback exhaust other than sound? Does the performance style provide more flow than the touring? What about the extruded honed exhaust manifold or is that not for the SS?

I realize the An aftermarket CB like Hahn's 3" CB will probably provide the best power increase, but the GM Performance stuff has the advantage of being covered under warranty. I don't want to have a loud exhaust, but I don't really want stock either.

 

GMPP Exhaust was dyno'd at a 12whp gain on a relatively stock SS/SC.

The Site Owner's actually.

 

Thanks, good info. Any idea if this was the performance version or touring version? Wonder if the TC will make much difference over the SC.

 

if you have an ss/tc the intake will not work. the cat-back will.

 

I don't have a Cobalt yet, but I'm looking to buy a new 2009 late this fall or early winter. The Cobalt SS is one of the two top cars on my list and my wife's fav, so as you can probably guess that's the one we'll get.

So, scratch the intake, but the catback will work.

 

The intake is only for 2.2L's and 2.4L's, IIRC. It won't work on Turbo or Supercharged models.

The Exhaust was the Performance version, IIRC. It's what I have. I love it.

If you have the Supercharged version, I'd recommend the GMPP.

If you have the Turbocharged version, I'd recommend the Corsa 2.5" or the Hahn 3".

 

agree!

 

Anyway to quiet the Hahn system down without sacrificing performance? It would be nice if they offered a quieter 3" muffler for us old farts that like a little more power, but don't want the extra noise. I already have a fast play-toy weekend warrior car, so I don't need or want a loud daily driver.

 

its not that bad man. i have heard hahns T/C in person with his 3" cat-back and its perfect

 

the hahn cat-back is not loud.. it jus sounds mean as hell

 

if you are looking for a new 09 car have you seen the hyundai genesis coupe? its not out yet but it will be nasty... rwd,mitsu evo motor and under 3000lb... need I say more?

 

My first thought was, I don't give a rat's azz about Hyundai. But, then I checked it out. Pretty impressive specs and a good looking car too.

 

No it won't.

The 2.0 turbo four is putting out like 207 HP in an OVER 3000 lb car.

The V6 model will be about as fast as a stock SS/SC

To the OP, stick with the stock unless you can get a 2.5" or larger, the GMPP exhaust sound good...but are only 2.25 which is too small for a TC car.

 

The genesis coupe with the turbo 4 is going to be impressive, it is the same motor that the evo has so there will already be an aftermarket for it. They say it will be 200+ hp since it will be detuned to go in this car. detuning is easily reversible this will be a cheap 300whp car.

 

Thanks for the info. Didn't realize the GMPP exhaust was only 2.25" diameter. Sounds like with a turbo, the 3" is the way to go. I guess if the Hahn is too loud, I'll look into a quieter 3" muffler or add a resonator or something. Probably won't actually start modding it until early spring, but I like to plan ahead.

 

Where are you getting this EVO motor information from?

The V6 is supposed to make 300hp, but the I-4 isn't going to be able to touch that without extensive mods.

 

Turbo cars have to run an open dp and a no resonator exhaust to be loud.

Turbo muffles things quite nicely

Not the same motor.

Close though...it is part of the global design that Hyundai and Mitsubishi designed together.

But it is not the 4B11

 

any 3" exhaust is going to be a little loud, if you are looking for a deeper mellow sound go 3". 2.5" is going to be a little higher in tone, I would stick with the Hahn exaust. It is as legal as you probably can get and am willing to bet because of this will be the most mellow. Just remember if you go with a downpipe like the synapse with no cat it is going to be much louder than if you retain the cat.

 

I know. I'd almost prefer a high flow cat in the downpipe. Someone will probably offer one within a few months.

 

High flow cat is the way to go for me. Keeps it legal, keeps the noise down some. I am not even planning on upgrading the downpipe anytime soon the stocker should have no problems for now.

 

Turbo muffler FTW , youll be fine with a 3" . You could prolly get away with just running something like 3" exhaust and a slp loudmouth resonator or dynomax bullet and still be quiter than a typical na or sc'ed 4 cyl with a 2.5 exhaust . So Hahns kit with a resonator and a muffler should make ya smile ....its sounds really good .

 

None of the GM performace parts listed work with the TC. I know I had the dealership call the Performace division. As an example, the catbacks are a 2 bolt vs a 3 bolt pattern on the TC. The Exhaust Manifold is also different due to the turbo. I hear parts are coming within the next 6 weeks, but who knows at this point...

 

The cat backs fit...

 

No, they don't... I own one of each so I know...

 

So hahn who has their cat back on their car is full of **** then?