well you seem to know alot so im gonna ask you another question, i decided to put all my parts on in one big install: dp header exhaust, intake, ottp stage 1 + 2.7, TB, dual pass h/e(new one), 60/40 meth, and after its all in get one custom tune. is that the best way to do it?

 

yes absolutly. Small changes such as an intake and an exhaust dont need to be bothered with...

the stage kit, bigger TB, dp/h and meth are the top things that need to be tuned for.. also, make sure you let your tuner know if you have a cat or not.. theres some things that can be tweaked to give you more power... also, take out tq reduction... thats a nice thing that will help...

To be honest, if i were you, i would dyno with the stock exhaust, and see what you get. If you change exhausts you really wont need a tune... see where you stand with a 2.5" exhaust, then see if you need to get the 3"

You could always get a retune, but you will save money by putting everything on at once and then getting the tune.

 

ye thats what i figured, the problem is no one in my area has any experience whatsoever tuning a cobalt.

 

ok so i am gonna go with OTT stage 1 and jbp header and the CTI catless downpipe and 3 inch CTI catback...couple questions. will the jbp header connect to the cti downpipe? and should i get the cti 3inch or is that too big for just those mods?

 

Yea it sucks.... canned tunes from OTT have seem to proven themselves around here.. they will tune for anything you ask for...

a personally tuned meth kit might yield more, as it is more specific... you can actually buy hptuners, and log the car, send it to OTT.. and they give you a spot on tune.

 

Oh go buy a 1" exhaust and call it a day! Gay orange cobalt driver........

 

that header should hook up to the cti dp.... if the vortex says it will hook up to stock dp location, and the CTI said it will hook up to stock manifold, then youll be good.

Also, having a 3" dp with a 2.5" helps with the whole velocity thing.. i run a 3" dp and a 2.5 and i love it.

 

yes. for the amount of air you'll be moving, 2.5" will give the best velocity. too many people are too quick to jump up to a 3" because for some reason they think bigger means more power. not true. you want the best velocity. yea, a 3" may gain some power over stock. but i bet a good chunk of the guys running 3" exhausts would gain more power by switching to a 2.5".

 

LOL thanks...SOOOOO 2.5?

 

will be perfect.

 

If your running a pulley smaller than 2.8 a 3'' would net more power. No, Im not providing proof... Search is your friend

 

i did some research... the ls4 tb improves the air/fuel ratio, combined with the 2.7 pulley the 3 inch pipes, 3 inch intake, the car would produce more power with the 3 inch exhaust

 

 

So with the mods i have stated it seems a 3' would almost be better overall, Intake,2.8,60's,3' catless DP, Tune...I MIGHT drop to a 2.7 but havent decided totally yet....and i will be getting a retune this spring so...

 

AFR is electronically commanded... nothing really "improves" the afr... the bigger TB allows for more air flow, and combined with a s/c thats ported, and some tuning... it could show you some gains.

 

sooo i am pretty sure i am gonna go with the CTI 3' magnaflow setup...any thoughts?

 

Great high quality setup

 

i was feelin that myself...But once again like i said, I am kinda worryed about the volicity issue and what not with it being 2 big

 

Is not to big as long as your on a 2.8 or smaller

 

until i get my muffler is it ok to run my 3" vortex header with the jbp 3" downpipe, stock muffler and catback? ill have the intake installed also(injen)

 

what does the 2.8 have to do with it?

I think that the 3" is going to be too big. Like i said earlier, majority of the people that have 3" exhausts would gain more power if they switched to a 2.5". but since they gained power on their 3" they don't realize that.

 

Meh. 3" makes more top end power. I'll be switching mine to a full 3" setup soon.

 

yea but you also have the mods to support that much airflow. some members can move that much air. but many can't.

 

Can't agree more.

If you aren't cracking 280+ out on a dyno, stick with 2.5" all the way.

 

does anyone know?