i have a 2006 cobalt ss/sc. mainly what i have done are exterior mods and a injen cai. but i want to do some other things to the engine. people are telling me get a smaller pulley and what not.

so my question is what pulley should i get, and i wanted to get different headers, but someone told me it would be a bad thing to do if i got different headers and kept the stock exhaust. why is that.

someone recommended to get JBP vortex headers.

also what would you recommend me to do to my car.

 

What I want to know is how you are going to fit more than one HEADER on your car. lol

 

V8 y0!, you should do what ever you want. Do some research on things like GM stage 2 kit or OTTP stage 1 kit.

 

i bought exhaust before dropping pulley sizes and regret it.. best bang for your money is smaller pulley, injectors and a tune.. i went with a 2.9 pulley and wow o wow is it awsome. but make sure if you go any smaller than a 3.0 you buy 60,s ( fuel injectors) i went with 42,s and there maxed out and i hit fuel cut right at about 6800 rpms. hope this helps out.

 

^ thankz.

and yeah i wanted to get some insight from other people.

stupid question, but what is a tune, and where can i get one.

 

a tune is a remap of the cars computer. it re calibrates the computer or ecu for higher boost levels, more fuel/ larger injectors, and what ever other mods you have. ottp has the best kit out from what i hear. personally i bought individual parts bit by bit and had a custome tune. but if you are to buy a kit from ottp (over the top performance) or zzp, they will send you a new ecu with a tune flashed to it already. all you do is pay the core charge and when u send them ur ecu back you get your money back.

list of things you will need.
1. retune for your mods.
2. one step colder plugs (i have ngk bkr7e,s)
3. pulley and hub (i have 2.9 size is your preference, the smaller the pulley the more boost)
4. injectors (like i said any smaller then 3.0 get 62,s)
5. shorter belt'
6. supporting mods. ( these cars hate heat so a heat exchanger is ideal. factory is just not enough cooling, also an intake will yield higher horsepower)
7. pulley puller from zzp. made my life so easy.
8. a good friend to help out
9. this website

 

1) Just dropping a pulley size wont net you that much hp. The pulley is a good mod to do after you have larger injectors. That being said, 1st step up from stock are 42lb/hr injectors, they can handle about a 3.0" pulley, but will need to get tuned and a shorter belt. 60lb/hr injectors can handle up to about a 2.6" pulley, but will need to get tuned and a shorter belt. The OTTP Stage I kit has great reviews. Look into that.

2) Getting a header (exhaust manifold) is a good idea if you plan on modding more in the future. A header alone wont net you as much as getting the header/downpipe/catback (full exhaust). But its a start...

3) JBP is hit or miss around here. I have it on my car, but need to get dyno'd to see what it really did... there is a thread about Header Testing and it has been dyno'd... but pretty shocking results

Other supporting mods: heat exchanger or dual pass endplate, colder plugs, transmission mounts/motor mount, umm... depends how much cash you have

 

thankz guys this is all useful

 

i am planning on getting the OTTP stage 1 kit. it looks good but i just want to know how it is.

also for people that have it, what are the options that you should choose (ex. rev limiter, torque management )

and for if and when i get it, where should i have it installed

 

Find a shop around you that does performance installation work. Something like a dynoshop of sorts. As far as the rev limiter you are 100% safe at 7grand, most say you can run up to 7250 give or take, and some have ran 7500 on stock internals no problem. Anywhere from 7-7250 is pretty safe though in my book. Torque management kinda depends on whether or not you are going to upgrade your traction mods. If you are not, I would limit boost in 1st gear. If you plan on getting rotated tranny mounts, then keep the boost at 100% in 1st gear. Other then that, ottp will take care of you .