Ok, so without getting flamed here I have a couple questions. I really dont know a ton about how cars work and knew little to nothing about exhausts. Ive been doing research for quite some time now before posting, and it seems to me that the Cobalt Turbo exhaust has two main components, the downpipe coming from the engines turbo and the cat-back exhaust portion. Correct me if I'm wrong. Now by upgrading the downpipe to a wider high flow cat or even going catless we get much more power and better sound. This sounds appealing to me and so I wont to upgrade my downpipe.
Ive read that the exhaust portion isnt worth upgrading as its more of a sound thing than a performance thing. Is this true? Will I see much added performance by upgrading to a full 3 inch exhaust with only a tune on my vehicle? Or am I better off saving a few hundred dollars and just getting a downpipe? Will the sound be similar between and upgraded catless pipe, and full exhaust upgrade, or will the fill exhaust upgrade sound much better?
If you guys could help me out here that would be greatly appreciated, I'm looking for more power and a louder nicer sound, and just not totally sure what to get.
Thanks

 

The downpipe will help exaust will also. Bigger is not always better tho. With our cars being turboed id say 3inch is your setup goal and if its,not it shoud be.id go with zzp catless downpipe and catback. And tune for it..........

 

ive asked questions about this as well.
i was told an exhaust is just about pointless because there are like no restictions in it.
deffenitly go with the catless downpipe with the muffler delete and you should be good IMO

 

catless downpipe and make sure u get a tune for it... the exhaust its always good to have... not going to see too much performance gains but on the dyno you would see like 5-15whp gains just from exhaust...no you mix the downpipe and the exhaust you could see gains up to 25whp... with a tune

 

you need a tune if you want to get performance from your cobalt. bolt-ons cant properly work/ hp gain is minimal if they arent tuned for your car. i would suggest researching the different tunes available for the cobalt, which there is a good thread on this website under lnf general discussion. its true that you will gain around 8-10hp with a 3" catted downpipe/ catless downpipe around 12-15hp and the sound is pretty decent with wot shifting. as far as adding a 3" full exhaust, i wouldnt bother, just more of an appearance than anything. save your money and invest in a tune first, then buy your bolt-ons when you know you can tune for them if that makes sense.

 

the muffler in the lnf cars are free flow like aftermarket ones, it has a straight tube with holes, so it really wouldn't matter much if you cut it other than sound, it does get rid of a bit of weight, that muffler's is kinda heavy, lol, the aftermarket kits have a little more diameter so they flow a bit better, you can also save a bit of weight depending on the material you choose, but the gains overall aren't that great

 

You will see your gains purely from the downpipe. The gains from adding a full 3" catback is nominal at best, and like you said is primarely a sound mod. The turbo doesn't flow enough air to justify anything larger than the 2.5" stocker.

Now with that being said... I personally do actually have a full 3" turbo back straight pipe exhaust. I did at one point compare the stock catback w/ zzp catless dp setup vs my full 3" w/ zzp catless dp on the dyno, and no gains were made. I did on the other hand absolutely LOVE the tone of the 3" straight pipe catback, so it stayed on the car for good.

just my .02