I want to order my exhaust from cobalt addiction to night any suggestion on which of the 4 they have for 500 or less which is best.
http://www.cobalt-addiction.com/performance.htm

 

with just stage II if you aren't going any further with mods.. gmpp is the way to go

 

I ORDERED OTHER STUFF TODAY HEADER DOWNPIPES 2.79 PULLEY COLDER PLUGS.
THEN TUNE IF I NEED IT AFTER ILL GET 65LBS'S BUT I HOPE NOT TO NEED IT JUST YET.
damn sry all caps i didnt see till done lol

 

gmpp should be fine for you then.... vibrant isn';t that bad eiether... haven't heard the dc sports one yet though

 

i concur

 

I say $304 Megan Exhaust from ebay, is a better deal but thats just my opinion. As with cobalt addiction, actually i've heard vibrant is pretty sweet ( my second choice). 3" is the way to go i believe, especially if you're going to run a 2.79" pulley and a 3" downpipe. I say why choke it up again after the downpipe.

 

think the gmpp exhaust with a 3" DP/High flow cat will hold me back?

with a 2.5

 

I dunno if it actually hurts performance, but i would hate to open up the exhaust flow, effectively slowing it down some, and then choke it back up to a smaller diameter causing more impedence of flow and creating an unneccessary pressure build up and heat. i believe more in starting thin and ending wide, i just haven't seen proof, and i'm sure it depends on the kind of exhaust and what not.

One fact is if you go from a 3" downpipe to a 2.5" or 2.25" exhaust, you're walling up (.25)*pi*radius^2 inches squared of surface area with a sharp transition that will cause flow eddies (turbulance) and slow down what could be a quicker flow = better torque.

Laminar flow is essentially what you want in an exhaust, it will put on the most power gains. This is why i dremelled the cruddy welds inside my CA header. If you are running a 2.5 inch pulley as well, i would go with a more open exhaust because you want the most heat expulsion as you can and keeping a gmpp exhaust will create more backpressure, keeping in more heat.

I'm pretty sure what i explained to be true, but i never did amazing in thermodynamics.

 

hmm i may just take off my stock dp, put in a high flow cat and get the extra bung welded in.....

 

what did you end up ordering?

 

I have thought about this topic for quite a long time. I have the 3" ZZP downpipe with hi-flow cat that has the 2.5" collector into the GMPP exhaust, which is 2.25". The benefit I see is higher torque numbers. I believe there were a few other people questioning my mods and torque numbers...they had exact mods except the exhaust was larger.....so, in hindsight, I think the ZZP downpipe would work well with a 2.5" exhaust setup better than my 2.25" and those both would work better than the 3" exhaust...that is, until you break the 300hp mark....then the 3" helps more. I might be wrong...

 

They suggested I get the 2.5 dc sport exhaust--ca stainless header--and 2.5 down pipe with high flow cat.so I did

 

nice combo.. let me know how the DC sounds.. only exhaust I haven't heard yet (or tested myself lol)

 

i got question about the DC exhaust, my car is bone stock atm and i am looking to get an exhaust the DC stands out to me but do i need to purchase anything else with it? i was looking at the one from cobalt addiction. I pretty much wanna get a catback exhaust that i can just bring to a muffler shop and have them install it for like 60-70 bucks. PM's welcome. thanks.