Should i use two and a half, two and three quarter, or three inch exhaust all the way around on the cobalt? does three inch affect back pressure? Thanks any and all suggestions are appreciated.

 

I say go 2 1/2" to keep a deeper sound. You are going hear many different suggestions though. Basically go 3" if you're going all out like 60lb injectors and a 2.6" pulley or something like that. Just my opinion.

 

if you're going for a lot of hp go three inch if not, you don't need to go more than 2.5

normaly FI engines need as little back pressure possible (large exhaust) but since we have such a small amount of hp (200hp is verry little compared to many FI engines)... its good to have some back pressure, for low end trq

if you plan on going 270-300+ hp then that rule applies

 

I have a 2.5" pulley with bolt-ons and supportive mods, and I can say that a 2.5" is fine. The theory is that you'd see more high end hp with a 3", but you'll make more torque with the 2.5". So far, a 2.5" exhaust has proven to be plenty for 12's in the 1/4 mile.

 

2.5" unless you make over 275HP then i would say 3"

 

would that go for the same with the bases and Lts? (minus the FI that is)

 

I would say the same thing, 2.5 for up to 275HP then after that go with 3"

All the cobalt exhuast are the same (as far as we know) so i am sure the 3" vibrant would work on the 2.2 and 2.4L

 

totaly agree!

 

i am making a custom 4" exhaust.

 

Read this thread:

https://www.cobaltss.net/forums/show...hlight=exhaust

It has cold hard facts rather than somebody that doesn't know what they are talking abouts opinion.

 

no, It doesnt work the same way for non FI engines.... for some reason N/a engines need back pressure... I dont remember why though, lol sorry

... you should stay small, your probly never gonna need a 3" unless you go FI in the future

 

so there will not be any power gain for the base/lt if we got the 2.5 cat back ( im thinking of hte gm catbacks mainly though- i believe that is the size that they are anyway.
if back pressure is the case, had do you achive that one?

 

I'm assuming if there were any gains, It would only be slight in the top end... and you would loose all bottom end power

I wish I could remember the reason for N/A engines needing back pressure cause that would probly help.... you should google it lol

 

i know a lot of car people laugh at civics with huge exhaust and loud ass muffler with power loss ZOOM ZOOM

 

i have a s/c cobalt i got a 2.5'' and it runs great and sound good!

 

well thats just the usual rice lol

 

Vette Jr, and Turbotech are correct.
Ive had both the Magnaflow, and the Borla exhausts on our project car, and with only an intake, and exhaust for performance, we noticed 1-2 hp difference between the two.

However, if you plan on increasing the boost, and putting in more performance parts, then larger diameter piping will flow even more, and increase your power.

 

well i have to add that i was out side a bit ago and heard a motorcycle screaming down the street in my direction. it was a red civic with a huge and i mean HUGE muffler hanging from the buttend. when i saw it scream by i thought to myself.. i could take it!

 

Also what sounds better Magnaflow...Borla...Dezod....Pacesetter.....or Corsa?
Post exhaust soundclips if able.

 

Go 1" all the way to the muffler. Then put on a muffler with an 8" outlet. Its the ricer Tuba/HP theory. Adds like 4 or 5 hundred horse.

 

the exhaust master thread has most of the stats and sound clips... i'l look for it....

 

https://www.cobaltss.net/forums/show...hlight=exhaust

it has a most but not all

 

 

have a question related to this cant seem to find it I have the 2.6 with 60's and just put on vibrant 3" catback, well I was setting 20lbs before exhaust and now i am any where between 15-18 just confirming if that was normal since air is leaving faster....

 

Any modifications pre-supercharger will net you more boost, any modifications post-supercharge will net you less boost. Putting on an intake will help more air get into the engine, putting on an exhaust will help you get more air out of the engine. What you are seeing is correct, hope that helps.