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".

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!:cssNET:

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.

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.

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?

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.

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.

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.

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.

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.

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.

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

Turbo muffles things quite nicely

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.

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.

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.

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 .

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.

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...

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...

The cat backs fit...

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

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 shit then?

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

If they say they have the GM catback and have not modified it, yes they are full of shit. I would assume they have a modified GM or made a custom exhaust of their own.

SSSC = 2 bolt configuration

SSTC = 3 bolt configuration

Nah they claim to have their 3" cat back on their car completely unmodified

Nah they claim to have their 3" cat back on their car completely unmodified

That would make absolute sense if it is their exhaust. I was refrencing the GM catback ehausts originally posted at the start of the thread.

That would make absolute sense if it is their exhaust. I was refrencing the GM catback ehausts originally posted at the start of the thread.

So you are saying that all these cat back systems have different bolt patterns?

Because the cat back I am talking about fits on all other cobalts as well.

So you are saying that all these cat back systems have different bolt patterns?

Because the cat back I am talking about fits on all other cobalts as well.

The GM catback exhausts were designed for the Cobalt through 2007. The 2008 SS has the turbo between the manifold and catback tying it in with a 3 bolt pattern which make the old exhaust systems incompatible with the 2008 SS. [Which Sucks]

The GM catback exhausts were designed for the Cobalt through 2007. The 2008 SS has the turbo between the manifold and catback tying it in with a 3 bolt pattern which make the old exhaust systems incompatible with the 2008 SS. [Which Sucks]

Yes, there is a turbo located between the exhaust manifold and catback, but there is also a downpipe mounted between the turbo and catback. So, while I don't know for sure if the earlier catbacks will work on the 08 or not, it sounds reasonable that they might fit.

EDIT: I just looked up the 2008 SS/TC Synapse downpipe and it indeed does have a 3 bolt flange where it bolts to the catback. Hahn must of change the flange on their 2008 catback.

EDIT: I just looked up the 2008 SS/TC Synapse downpipe and it indeed does have a 3 bolt flange where it bolts to the catback. Hahn must of change the flange on their 2008 catback.

Wow someone figured out what I already posted was correct... :cssNET:

It's funny that the hyundai was just mentioned. Only because I was going to post something about seeing 3 of them at the hyundai corp in orange county. I work at a city college and hyundai donates alot of stuff to us and sema was there doing some special write ups on the car. Since i had to go into the back shop they had the coups there and they look pretty good. I wanted to take a pic but the guys at hyundai said no pictures. The guys from sema were all over the cars. I did like what they look like and since I go there pretty much I'm going to talk to one of the instructors there that teach the new techs how long it will be before I might be able to take some pics

Also the car will be weighing in at approx 3200 /3500 lbs

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?

It's funny that the hyundai was just mentioned. Only because I was going to post something about seeing 3 of them at the hyundai corp in orange county. I work at a city college and hyundai donates alot of stuff to us and sema was there doing some special write ups on the car. Since i had to go into the back shop they had the coups there and they look pretty good. I wanted to take a pic but the guys at hyundai said no pictures. The guys from sema were all over the cars. I did like what they look like and since I go there pretty much I'm going to talk to one of the instructors there that teach the new techs how long it will be before I might be able to take some pics

Also the car will be weighing in at approx 3200 /3500 lbs

It should be a nice car once you take the hyundai logo off :lol:

It's funny that the hyundai was just mentioned. Only because I was going to post something about seeing 3 of them at the hyundai corp in orange county. I work at a city college and hyundai donates alot of stuff to us and sema was there doing some special write ups on the car. Since i had to go into the back shop they had the coups there and they look pretty good. I wanted to take a pic but the guys at hyundai said no pictures. The guys from sema were all over the cars. I did like what they look like and since I go there pretty much I'm going to talk to one of the instructors there that teach the new techs how long it will be before I might be able to take some pics

Also the car will be weighing in at approx 3200 /3500 lbs

They will be releasing a tuner version after the car is first released which will be lighter... am I the only one who has seen this? Last time I checked I didnt know of any other 4cyl turbod motor mitsu makes other than the 4b11... and since there is no official word on the motor, kind of makes you wonder. If they detuned it for the raliart lancer why not for the genesis???

If they did not intend on doing something interesting with it why would the designers be attending all kinds of drift comps??? I guess we all just have to wait and see.

Nah they claim to have their 3" cat back on their car completely unmodified

Incorrect! the piping is the same, the FLANGE is different! The people (LIKE ME) that purchased one in the group buy had to specify that they have a TC to get the correct part!

If they say they have the GM catback and have not modified it, yes they are full of shit. I would assume they have a modified GM or made a custom exhaust of their own.

SSSC = 2 bolt configuration

SSTC = 3 bolt configuration

ABSOLUTELY CORRECT, qft.

Do not buy a 05-07 catback and expect it to bolt on an '08, a bit of welding would be required.