Just got a quick question. sorry if there's a search for it, I'm just at work and wanted to make a quick thread for answers later.

I see some people have the GM Stage 2 but they run a 2.9" pulley instead of the 77.9mm or 3.0" that is comes with. I have a few questions. One would be would the 2.9" pulley require getting retuned or would the reflash that comes with the GM Stage 2 work? Another question where could the 2.9 be purchased? anywhere like zzp, ottp, ced? i see they all have a 2.9 inch so I would assume it doesn't matter which you go with. another question how much psi would this run? i'm guessing about 16.5. What would the gains dropping from the 3.0 to the 2.9 be?

If you can break down each answer for each question. Thanks! depending on the results of the answers I'll definately be looking to drop from the 3.0 to 2.9 in the future after header/downpipe/catback..

 

Yes it can be ran on the gms2 tune, but i would recommend getting a better tune anyways since the gm tune leaves a lot of power to be desired since its VERY conservative. For boost, on stock exhaust you would probably see 16psi or so, but get a full exhaust and that number will drop to a nice 14psi or so.

 

right now i'm running a megan muffler. plan on getting bad-mab shorty, zzp 3" catted dp, and just a full custom 2.5" to the megan muffler and then a zzp intake before i get the custom tune. I've seen numbers as high as 20 psi in 4th gear at redline on below freezing nights. I'm assuming this has to do with my stock header/downpipe.

 

How cold is it when you see 20psi? On the stage 2 pulley you really shouldnt be seeing that in any temp. What boost do you usually see on a warm day? Getting that full exhaust will drop it down a nice amount

 

you can get the pulleys here

Smoothflow Pulleys

 

The only place fourth gear pulls should be done is on a dyno, shame on you

 

lol first off, why are you doing well over 115 mph, second, its cuz of the air temp, forced induction cars run better in the cold, has to do with the amount of air you force in, since its cold, the air molecules are closer together, so you run more air which=more boost, but its also not good for the car, specially if you dont have the cooling mods to do it


also ive never heard of people getting full 3" exhaust, and dropping boost lol

 

Thats sarcasm right? lol

 

hopefully lol

 

the 4th gear pull isn't a common thing whatsoever. I just happened do a rare 1st 2nd 3rd pull on a cold night and 3rd at redline was seeing pretty high numbers. higher than 2nd at redline so i decided to check and see if 4th at redline was higher than 3rd at redline which it indeed was. so i guess if i got bad mab header, zzp 3" catted downpipe and then got from the stock resonator back redone with 2.5" piping you think it'd show normal numbers then? or do i need to get all new pipes from the catback? I wanna stay catted and resonated.

 

If you typed GMS2 with 2.9 in the search feature you would have found your answer.

There are a million threads asking this. I'm not trying to be a dick, but please do your research. Without research you will never learn, and being spoon fed information on this site is not always a good idea. Alot of the time you will get peoples opinions over facts. Go do some reading, and if you still cant get a straight answer I'm sure one of us can help you.

 

yea sorry man as i said i was just at work so i wanted to make a quick thread while i was at work so i could read up on some of the replies after. If you notice i don't make a whole lot of threads on the site because I use the search bar most of the time

 

I'm the same way, just not the make the post and research later.

 

as i said lol. i was at work so i just wanted to make this post to get some feedback so i could return to my thread when i got home from work. i researched though and 2.9 really doesn't seem worth it especially on the 42's. i'll stick with my 3.0 and 42's and just get a custom tune.

 

I have a 2.9 with 42's and custom tune. 265hp to the wheels.

a 2.9 is definitely worth it imo. that little extra PSI really comes in handy.

(stock downpipe with cat cut out and magnaflow 2.5")

 

I ran the 2.9 on GM's tune with zero issues. Put down 255whp with it and a few other things (intake, exhaust). I got mine from Nate (Smoothflow pullies), but I'm not sure if they're around anymore. Haven't heard much from them in a while

 

Yes, Nate is still around.

He has made me 3 different pulleys in the past few months

Nate def has the best pulleys around, and he can make them any size you want.

 

I need to order a new TVS pulley from nate pretty soon

 

my main focus right now i guess is just gonna be gettin the whole exhaust taken care of. Pretty sure i've fully decided on the bad-mab shorty, zzp 3" catted dp, mendralbentexhausts.com's 2.5" catback to the borla muffler with the 18" magnaflow resonator. I'm guessing the tip it comes with is 4"? anyone know?

BAD-MAB.com

Cobalt & Ion ---> ZZ Performance

05-10 CHEVY COBALT EXHAUST - BOLT ON - (304 STAINLESS - 2.5 IN)

ADD ON RESONATOR OPTION - 18 INCH MODEL