Basically I searched all over including ************* and couldn't find my answer! It's an easy one too. My cobalt ss/sc is stock and I was looking for a basic upgrade since I'm saving my money for school and I want the car to last during my time in school too, so I'm just looking at the GM stage 2 kit. No ZZP or OTTP, just GM. So I was wondering if I NEED an exhaust or is the stock one going to be just fine?! Will the car suffer because I'm not opening up the exhasut more? I'm not all about performance, just want a little bit more get up and go. You guys know how that is btw if your guys' answer is yes it's fine then I'm ordering it today unless someone has it for sale in the twin cities area! Thanks!

 

lol its fine,that wont really affect anything at all. GM stage kits are just too damm expensive and for that same amount of money u can just get plenty more stuff on here and even better gains. but if u just want gm stage 2 the stock exhaust will be just fine and wont affect perfomance much. if u wanted to open up the exhaust later on just go with a 2.5 cat back and ur set.

 

The stock exhaust will be fine. I was a GM2 when i first got the car. Its a GM upgrade so its completely safe.

If your interested i have the 42's injectors w Harness, GM 77.9 Pulley and even an Injen Intake for sale. I would be a nice bundle at a low school cost. Only extra thing you would have to get is for someone to flash you with a GM2 tune, Belt & 4 Bolts from ZZP.

 

OP you'll be fine with the stocker, although honestly if you're planning on spending 500 bucks on the parts, and an additional labor cost to get it installed, then I don't see why you don't go with zzp's kit. It's not anymore dangerous for your car than GM's pig rich tune for the stage II kit. Not to mention they'll throw in a heat exchanger with their kit, and it'll still cost less than GM's kit.

But I digress. Your car, your choice. You'll be happy either way.

 

parts are parts. whether you buy the expensive GM parts or the cheaper (but same if not better quality) zzp or ottp. they all do the same thing. if you have any plans in the future, the hub that comes stock on the charger is a 4 bolt, and all of the performance pulleys, to my knowledge, are 5 so you will have to have a different hub anyway. i would go with the zzp kit. i have the GMS2 parts just because i bought the car from the dealer with them on.

i would just go get the Trifeca GMS3 tune, or even just a trifecta tune over the zzp PCM or whatever tune they give you. Its more personalized to your car and probably costs just about the same, plus you get more power.

 

Thanks for the answers guys! Yeah I read about how you run pig rich with the stage 2 tune but it seems like the way to go since I'm shooting for dependability and I have no idea if the flashes from ZZP or OTTP would be fine to run for years down the road, or if I'd have to go get a tune right away?! Our family friend is a certified mechanic and would be able to install everything for no cost along with the flash which makes things easier and more affordable.

 

I hope your friend is a certfied GM tech, because the only he's gonna be able to load the reflash is with a tech II. And unless he's loaded with cash, the only to get one is to use the one that the stealership provides to its techs.

And no one has ever had a problem running a canned tune from OTTP or ZZP. People just opt to get retuned because, as someone mentioned earlier, each car runs differently and can handle a little more or less from a tune. But OTTP and ZZP has NEVER sold a product that they haven't tested before hand. ZZP actually goes the distance and dyno tests their products.

 

Would reading his tune and doing a copy all over from a gm2 tune ad doing a rewrite not be the exact same thing. As far as i know it is. It would be GM2 Specs under his VIN.

 

I had no idea about the flash so sorry for my ignorance on that. I knew that ZZP and OTTP flashes were/are dependable but I thought to a point. Going with them really seems like the way to go though since maybe next year I can just get my car fine tuned at a local shop. I looked through all the threads about OTTP vs ZZP canned tunes but it seemed like the only thing that made people choose which one to go with was loyalty to a company of their liking. I'm looking for the most non-aggressive tune since dependability is right up there in what I want. What would seem to be my best choice between the two? (sorry to take this off my original subject guys)

 

Well from what i have seen the GM2 tune runs an afr of 10.0 while the zzp and ottp tunes are around 11.3 at WOT. OTTP & ZZP also have a more aggressive timing table. This is what i have seen personally, others have seen zzp and ottp tunes in the 10's stock but i never have. If its in the 10 range its pig rich while 11.3 is leaned out a little but still as safe IMO. Our danger zone is higher than 11.9 ish i believe.

 

Actually, stoich is 14.1:1, so the danger would be leaning it out past that at WOT. Also, the main reason the timing is aggressive is because of the bigger injectors (60lbs/hr as oppose to GM's 42lbs/hr).

OP, as far as dependability, all three companies are reliable. I have a preference for zzp simply because they've put the time and money into fabricating most of their own parts, and into R&D, which is rare. OTTP outsources lots of their parts, although it comes from several quality companies. So it's really up to you. I should mention, however, that I bought the gm stage II kit, then switched to OTTP's stage kit with zzp's heat exchanger.

 

stoich is actually 14.7:1 and you keep a richer mix to keep cylinder temps down. a 14.7 would be hotter than a 11.9 ect. Im a college student with the S3 trifecta and i have no problems whatsoever. if anything i notice better gas mileage and more power with the same dependability. honestly i would piece together a kit from used parts lol. just get a hub with a pulley, 42# injectors, a shorter belt, and then get trifecta to do a tune. i think the rate for me was 250 for a regular tune and 400 for Trifecta GMS3 and unlimited dyno time

 

I have a set of 42 injectors and harness with gm 77.9 or zzp gm 2.9 pullet for sale along with a Injen Intake.

You could take that for 200 and order the 4$ bolts and 30ish dollar belt. Then have someone load the GM2 tune and your all set.

I paid 200 for my GM3 Tune+Trifecata Options and loaded it with HP Tuners myself and was then tuned by BYT for an additional cost later.

 

this.