What do you think of the GM Cat Back system ?

 

That is my next mod. It sounds real good. Here is a sound clip. It's my favorite exhaust for the sound and the price.

http://videos.streetfire.net/player....1-C28FBF40C543

 

Sound's pretty nice. But, my real question is, what's the difference between the GM one, and a Magnaflow one ?

 

Just go here and all your questions will be answered my friend. Here are all the exhausts for our cars, where you can get them and how much they cost.

https://www.cobaltss.net/forums/show...ficial+exhaust

 

Nice thanks a lot !

 

Not a problem my friend. Good luck with your purchase.

 

The more i hear them, the more i want one. But, well who knows how it will sound on my 2.4l

 

Cold air intake before Cat Back ? or Cat back before CAI

 

not much. Why doesn't GM claim ANY power increase?

I e-mailed them about this---they basicaly said its for looks/durability.....power is "subjective" they said.

Wow---thats so convincing! I really want one now

 

pretty much every exhaust is the same, and GM could probably care less about dynoing an exhaust system...

 

I have the gm performance catback on my 2.4 and I would not have any other.

 

There is probably a 4-5hp increase and a 8-13 torque increase right ?

 

i don't think that the factory system is restrictive at all. at least not on the 2.4 and S/C. If there is an increase, it's a few HP 2-3 and similar torque gains.

 

It's a pipe like the other one, why would it not give hp = to like, the magnaflow one ?

Please explain me this someone !

 

AFAIK the magnaflow is a larger pipe, so it may have better flow to it. assuming all else is stock, i don't think that there would be a huge diff from one to the other.

 

I went with a universal Magnaflow on my 2.4. I did not replace any piping because I do not think that an N/A 4cyl. needs to have larger diameter piping than what comes on it. It sounds really good for a 4 banger. $159 installed

 

i tend to agree with this. it's either two and a quarter or two and a half and i think that it's stainless steel. a quality high flow muffler and mandrel pipes could easily be fabbed up by a decent shop. which model muffler did you end up with?

 

Heres a tip

Never try to guess or expect a certain amount of horsepower even if someone with the same exact motor and/or setup.

 

I have the GM CAT-BACK performance exhaust on my car. I actually installed it myself. I had to cut out the original exhaust with a plasma torch. That was the only hard part. It fit perfectly during install. All you have to do it push it into the rubber clamp things. The rest is all bolt on and it holds extremely well if you do it right. The sound is great! Its not an over kill and it fits the car perfectly. I am not sure about performance but It is built just like any other aftermarket exhaust. It doesn't sound like a rice burner at all :-).

 

I love mine! Its just loud enough to be enjoyable without being illegal or annoying, and its not a fart can.

 

You'll see minimal gains with the GM exhaust simply because the exhaust on the 2.4L SS is 2.5" from the cat to the axel. It narrows down to 2.25" to jump over the axel and into the muffler. The GM cat-back is a full and true 2.5" mandrel bent exhaust from the cat-back. You're only eliminating a .25" restriction from the axel back (plus whatever restriction the stock muffler provides versus the aftermarket one).

You're almost better off getting custom exhaust work done from the axel back just to jump it to a true 2.5" cat-back exhaust. It'll be cheaper. However, you won't have the nice stainless piping from the cat to the axel then.

To see any real gains from the exhaust you're going to have to put in a header and high flow cat (or cat-delete). I think the 2.4L exhaust is smaller than 2.5" in the downpipe. It only jumps up to 2.5" from the cat exit. So really you have to mess with the header/downpipe/cat to eliminate all the true restrictions in our exhaust.

I could be wrong about the size before the cat... anyone know for sure? I'm about 90% sure of myself.

As far as Magnaflow goes... the only difference you'll notice is price and sound. I'm not sure of the size, but anything larger than 2.5" won't make a difference on our n/a motor. I think even with f/i it wouldn't matter for our motor. 2.5" is plenty large enough for a 4 cylinder.

 

The GMPP cat-back is 2.25 and the stock exhaust is 2.5. The bottle-neck for the stock exhaust is the cat and the muffler. Change these 2 things and you'll get the same if not more in the terms of gains for less money. ZZP recently came out with a downpipe and high flow cat combo, which is $249 IIRC. That in addition to a $100 high-flo muffler would be a much better investment than a cat-back.

 

GMPP cat-back is 2.5". I watched my buddy install it. The stock is 2.5" from the cat to the axel, like I stated. Check it... there's a little knuckle right in front of the rear axel (on the 2.4L SS, not the 2.0L).

You're right about the cat though. That's the true restriction. An aftermarket header/downpipe/cat will give the most gain.

 

Thanks for all your answers guys

 

Personally... the Magnaflow is perfect... all I could ask for in a exhaust system.

Not "heard a block away" loud... at idle you can just barely tell it's there.

There's no fart can sound to the system at all. The sound clips on Magnaflow's website of the Solstice exhaust (same piping size, same engine) dosen't do the system justice.

As best as I can describe it... takes all the sound the engine makes up front... and just moves it out back. No distortion, rasp, or anything.

IMHO... definately worth the money for a nice refined sound.