is a magnaflow 3" racing series exhaust overkill for a cobalt around 280 whp. on the site they stated: "The Race Series is recommended for the serious racer, turbo, nitrous oxide fuel systems, or wild cam applications."

vortex header + cti downpipe +(racing series exhaust)?

 

mmm....kind of yea. 2.5 should cover it.

 

right now yes.. if ur going to get meth, ottp stage 1 and all of that **** then it wouldt really be overkill

 

wellim starting with a base= vortex header, cti downpipe exhaust and intake, but i plan to have the ottp stage kit with the stage 2 belt a 2.6 pulley, ls4 throttle body, and a 90/10 meth tuned

 

Once you hit 300 WHP you can use it. Till then its a waste.

 

i doubt i'll hit 300, are you sure? im buying from magnaflow tmrw at 2 pm, so i need to know stats

why wont it be needed under 300 whp? i hear mixed reasons, how about some science for the newb?

 

You'll lose your lower end torque. 3" flows more then your engine needs.

 

alright, so the ls4 tb upgrade increase air/fuel ratio, and ill be running high boost around 20 psi, probably between 280-295 whp. 2.5 is the one i should go with

 

You'e actuay close enough to 300 whp IF and I mean IF you hit 295WHP to run 3" and be able to justify it. You're best bet would be to dyno the car PRIOR to getting the exhaust to see exactly where you are so you can make the right decission on what your car needs.

 

hmmm that might pose a problem, ill only have the stage parts by april, the question right now i should be asking is a 2.5 exhaust suffiecient for 280 -295whp?

 

Yes the 2.5 will be enough but if you're planning a future BIGGER upgrade then the 2.5 will become you're weak link. If I were you I'd wait till After I did the stage parts to get the exhaust. But if youabsolutly HAVE to get one then go with the 3" seeing you are planning more right around the corner. If this was where you were gonna stop modding or wanted to be then I'd say go with the 2.5. But like I said you ARE planning more so it makes no sence to limit yourself by the 2.5.

 

the mods that i listed to you are the end of the line, no more power mods after that, and im getting a deal on a specific muffler near by, a racing series for 2.5 or 3 inch for 200 after tax including the resonator.

 

you can never be to big with a forced induction engine 3 inch will be fine

 

this is not true. turbos are a little different that superchargers when it comes to exhaust. a turbo loves a huge, free flowing exhaust. a super does not. has to be sized properly.

 

I say 3" will be ok. Anything over 250hp will see an overall gain with 3". but you will lose some lower end torque as mentioned, only to gain hp up top.

 

2.5 for your **** dog

 

**** the exhaust. cut it off. lol

 

Oh look, someone else who doesn't know what they are talking about. Goodie!

 

**** IT!!!!

 

superchargers dont like back pressure from what i've read, and from what i hear the 3" opens it up quite a bit, i have 3" on mine and i'ma guess around 250 give or take

 

Its velocity we are worried about, not back pressure.

2.5" at 250hp will have the exhaust flowing faster (which is better) than a 3" at 250hp.

You will see better improvements if you were to go 2.5".

 

doe sbackpressure not effect velocity? i'm going tvs so i'm content for now

 

Theres a difference.

 

i'm just sayin, to me back pressure and velocity seem directly proportional

 

Not really.

hold on.