Hey guys...I just bought a new '07 Cobalt SS/SC and I have the stage 2 engine ups, and I wanted to get header and full exhuast and leave it there untill i can catch up on my payments, and save some more money and what not (im only 19 going to college and workn so be easy on the money flames)...

Anyway, I saw the post at the top about all the headers for the vehicles...and I was initially going to go with the zzp or the pacecetter. I have a few questions so I will list numbers to make it easier.

1)Which do you think is better for the S/C modles 4-2-1 or 4-1? Since most of the headers are 4-1 i assume that is best. And I can't never remember which one is best for low end and highend power
2) The zzp has a 2.89 exit, so would it be best to go with 2.5, 2.75, 3.0 exhaust? and what whould the extra, or lack of backpressure do for the vehicle?
3) is the zzp for 2.2, 2.4 or 2.0? or does it matter?


Also the cat-back systems I see for sale, IMO are way overpriced (considering i had a custom exhaust done for about the same amount, and it was dual exit and it didnt have fart can on it) and they all come with those rice cans that I hate so much. What did all you guys do for exhaust, and do you have sound clips?

thanx to all
-Rob

IM going to get the GMPP header with my S2 could anyone hear a diff exhaust note.

does anyone here actually know anything about performance for Cobalts? I ask because I've noticed not many people respond to the performance upgrading questions...

^^ no offence, and dont mean to bash

nothin against you BEEOTCH, but i think most of these subjects have already been discussed

header back exhaust systems sound like crap on our cars, do your homework before your stuck with a loud annoying car

um thats why I'm here... I just wanna know what I can do to get a nice sound. I know a buddy of mine who has an SRT-4 and has 3 in str8 pipe and a resinator where the cat would be... and it sounds pretty nice, but i have a 2.0 and srt4 is a 2.4 so that might have sumthin to do with it. But Im just gettn suggestions

Your car will never sound like an SRT-4, so get that idea out of your head. :p

You said the collector is a 2.89" outlet. So your best bet from a performance standpoint is a 3" header-back exhaust. Don't ever downsize your exhaust. Always go from smaller to bigger, never from bigger to smaller.

It's up to whether to go for sound or performance, because they do not go together. IMO, a 3" catless header-back with a straight through muffler sounds just fine, but then again I'm used to my Eclipse that sounds more like a dump truck than a car. "Sounds good" is in the ear of the listener, so it's hard to tell you what will "sound good" on your car. But IMO, simply judging by the fact that you asked for sound clips as opposed to just asking for the best flowing exhaust would tell me that you aren't going to be very happy with how these cars sound with any modified exhaust, never mind a free flowing one.

i wasnt judging on sound alone...I was just asking for clips. I am aware that my car will never sound like an SRT-4. I was just stating what he had and it sounded pretty good. Personally, I don't really like the sound of any 4cyl, b/c I'm more of a muscle fan. I just want an exhaust that has nice sound that gives the best power I can get. Obviously, free flowing would be the best for performance, and I was told that the longer and more ovular mufflers give the deeper sounds. But again I don't know how those different styles of mufflers affect performance...or resinators for that matter. I assume which ever one restricts the least.

Correct, less restrictive is better. Just about any straight through "muffler" will flow the same. As you said, you can get different size/shape cans to change the sound. However, although you can change the sound a small amount, with a free flowing exhaust the car is always going to sound like a 2.0L non-turbo I4 with a free flowing exhaust.... ironic because that's exaclty what it is. lol ;)

lol...true. My biggest thing is I really dont like that raspy "rice" sound, and I just bought this car and I really don't wanna get stuck with that.

Your car will never sound like an SRT-4, so get that idea out of your head. :p

You said the collector is a 2.89" outlet. So your best bet from a performance standpoint is a 3" header-back exhaust. Don't ever downsize your exhaust. Always go from smaller to bigger, never from bigger to smaller.

It's up to whether to go for sound or performance, because they do not go together. IMO, a 3" catless header-back with a straight through muffler sounds just fine, but then again I'm used to my Eclipse that sounds more like a dump truck than a car. "Sounds good" is in the ear of the listener, so it's hard to tell you what will "sound good" on your car. But IMO, simply judging by the fact that you asked for sound clips as opposed to just asking for the best flowing exhaust would tell me that you aren't going to be very happy with how these cars sound with any modified exhaust, never mind a free flowing one.

Correct, less restrictive is better. Just about any straight through "muffler" will flow the same. As you said, you can get different size/shape cans to change the sound. However, although you can change the sound a small amount, with a free flowing exhaust the car is always going to sound like a 2.0L non-turbo I4 with a free flowing exhaust.... ironic because that's exaclty what it is. lol ;)

Since you seem to be the expert, can going down in size actually increase flow? Can horsepower/torque increase when you go to a smaller size exhaust diameter piping?

Actually, I know the answers to those questions. The GMPP exhaust is actually smaller in diameter than the stock exhaust but flows much better. It increases torque and horsepower and the smaller diameter piping of the GMPP exhaust has benefits of greater torque than a larger comparable exhaust.

As far as the extruded/honed manifold, its a great alternative for those looking to get a few extras as far as torque and horsepower and not raise the 'warranty' issues with dealers.

As far as which header is the best, I think they are all very similar. Some people prefer a 4-1 while others like the 4-2-1 design. I have had a few different header combos and I believe you need to think about where you want to be with the exhaust before you replace it.

If I had to go with another exhaust I'd try the pace setter armor coated header and a 2.5" downpipe with hi-flow cat into a 2.5" corsa exhaust. The other alternative is going with a full CTI 3" setup. I'd prefer the CTI over the other but it costs a lot more.

I'm pretty sure you could work around the price. Obvs. 450 bucks for a cat back exhaust is pretty decent, considering what I've seen other cat backs go for. From the picture shown its a magnaflow one. 650 for the header tho...thats like wow

Since you seem to be the expert, can going down in size actually increase flow? Can horsepower/torque increase when you go to a smaller size exhaust diameter piping?

Actually, I know the answers to those questions. The GMPP exhaust is actually smaller in diameter than the stock exhaust but flows much better. It increases torque and horsepower and the smaller diameter piping of the GMPP exhaust has benefits of greater torque than a larger comparable exhaust.


By all means, post up some dyno proven evidence. Is the smaller pipe better flowing or is the better flowing muffler the part that's making all the gains? Where's the dyno chart of the small GMPP exhaust compared to a 3" exhaust with a straight through or no muffler?

By all means, post up some dyno proven evidence. Is the smaller pipe better flowing or is the better flowing muffler the part that's making all the gains? Where's the dyno chart of the small GMPP exhaust compared to a 3" exhaust with a straight through or no muffler?

I was referring to the stock exhaust, which is 2.5" in diameter and the GMPP exhaust which is 2.25" in diameter.