Hey guys, im new to the site and just recently purchased a 2007 Cobalt SS 2.4L N/A. I have a few detailed and long questions, to which I would appreciate serious and thoughtful answers to. I don't want any flames or anything becasue If i can't get help here I will just move on, I don't want any trouble. and yes I have read several threads about these topics, but I want someone to clearify it with me and have all my answers in one place, if thats not to much trouble.

Ok, first question:
1.) I need someone to explain what exhaust is on my 2007 2.4L SS, and what the GMPP exhaust is. Im guessing my stock exhaust is 2 1/4" and i hear the GMPP aftermarket is 2.5", is that correct? Please tell me the diameters of both and if possible the gains/losses in HP.

2.) Next, I want to buy a CAI and I hear the Injen and K&N filters may void my warrenty, is that true? If I decide on a GMPP CAI, will it provide the same or close to the same gains as the others?

3.) I plan on buying some 17" Konig rims. They will fit on my stock tires, with no problems correct?

4.) Would someone explain to me what the pulley will do for my car, and possbily recomend me to which I sohuld buy. Along with what I will need for it to work, such as belts, etc. Also, do they void the warrenty?

5.) Lastly, Is there anything I should get to help my car in performance, that I havent metioned, that costs under $500?

Thats it, thank you very much to those who decide to hlep me out. Like I said im new to the game and im only 17, so I still have a lot of learning to do. I appreciate it.

Peace!

 

First of all, swapping out your crank pulley on the car WILL void your warranty. And if that's what you care about don't do it.

Second K&N intake will NOT void your warranty. If it does call K&N, they advertise that it WILL NOT. GMPP intake is okay, but not the cheapest.

The GMPP exhaust sounds good and is 2 1/2 inches, but it provides a dyno proven ~1.8whp. And that is from the pages of GM High Performance Magazine. You need to weigh the hp/$ ratio and see if it is worth it for you.

Also you can look into a tune. You can pick up 10-15whp with a good tune, and those can range from $125-400.

 

The GMPP cat back is 2.5 and is freer flowing due to the straight thru style muffler. The factory system is also 2.5 I believe but the muffler is horrible.

I have the GMPP intake as well cause I didn't want ANY warrenty issues. The possible 1 or 2 hp you may net from another style is NOT worth it if you get hassled at the deaership.

17's will fit just like your stockers do. Just make sure you stick to the same size wheel as factory if you plan on useing the factory tires.

I don't know of underdrive pullies for our 2.4's so I won't comment.

And lastly I need to know if its an auto or 5 spd.

K&N are oiled and the oil is what voids your warrenty. BE CAREFUL!

The dyno results I'veseen show a 10 hp gain to be had from the GMPP catback.

A good tune is awesome but they are still in the works for the 2007 car.

 

If you care to read abotu your GMPP intake and exhaust, this is your most hopeful article:

http://www.gmhightechperformance.com...alt/index.html

 

I was refering to other members who have dynoed thier cars before and after. With GM I don't believe any of thier dyno results seeing how too many times they're wrong.

 

Thank you guys a ton!
and it is a 4-speed Auto w/ OD

 

A good trans tune can knock off almost a full second in the 1/4 mile as proved by Illmatic and a few others. But as I said the 2007 car tunes are in the works. Yes the 07 is different then the 06 but Steve could fill you in better on this since he's a tuner.

Also forget the GMPP manifold (header) and go with a CA header which has been dynoed to add 10 to 15 HP on the 2.4.

 

But that will void his warranty for the most part.

Well that's a third party magazine. So I'm more inclined to believe someone who doesn't sell the product. I doubt they would be trying to help the products image by boasting a ~1.8whp gain for $500. **** if I charged that much per HP my 2.4L tunes would be $2,000-3,000!

 

Yes, im only going to be purchasing parts that WILL NOT void my warranty.

So how much will the GMPP Manifolds add HP wise? Compared to the CA's which add 10-15?

 

It voids your warrenty on your manifold gasket, and the header itself. Nothing else gets voided since the header doesn't effect anything else.

Well thats what the dealership told me anyway.

Thats really odd seeing how members here have dyno graphs showing more gain then that.

The GM manifold may net you 2 hp if that, not worth the price. Check with your dealership as mine and the ones around here won't void your warrenty other then that of the manifold and gaskets.

 

That's what the dealership told BALLSOUT too, until he went in for engine problems and the GM Rep basically told him to go lick his own colon.

And as for the now looked up results. The GMPP exhaust yields 1.2whp and 1.3wtq. And that was dyno'd at Tune Time Performance.

 

So basically with all my planned mods GMPP CAI, GMPP Headers, and GMPP Catback, i will only gain 15-20 HP for $1000?

 

WOW! so then everyone else who has posted dyno graphs are nothing but big fat bold faced bull **** lyers! God damn them! Thats it I'm gonna go burn my car to the ground! I should have never bought this car, I should have just gotten a Civic.

Thats about right.

 

ok ty, you all have been a great help, im off to work! peace

 

The gm catback is 2.25 pipping. Not 2.5 but is a decent option for the car.

 

Whoops, thanks for the correction.

 

find someone to take out the torque management via hpt.

make sure the car actually goes into pe.

throw 4 degree's of timing at. call it a day.

 

more timing if he ran 94 octane

 

i was being nice

 

No point in exceeding +4* because power will fall off after that advance on the top end. You an add more down low though.

Nobody would think you were cool if you got a civic. You are at least where you belong. Sure, you can get some more hp out of an exhaust, but I doubt it would be even close to 10whp on exhaust alone.

If you do intake, headers, downpipe, exhaust, and tune you should have 180-185whp. Give or take depending on your tune and the dyno used.

 

I was kidding bud.

 

I would stay away from the GM ripoff of the honed manifold though...

...just get the CA shorty header...and yes the GMPP exhaust is 2.25"...and no one wants to mention AEM CAIs...

 

i run shell mid-grade in the winter and will run shell v-power premium in the summer.

 

Always run 91-93

It is less than 2 dollars a damn fill up

If you are that broke...sell your car and get an Accent of an Aveo...god

 

the dealership filled my car with regular gas, so im sure they think it's fine for the engine.