Hey, I see you have a 2.5 pulley, and the gm stage 2 belt. Do you still need a different tensioner pulley with the shorter belt. I'm getting a 2.6 pulley and if I can avoid the cost of a different tensioner pulley that would be awesome!

 

yea i run the larger 76mm idler pully.

if you talk to jason(waylin) he can tell you about all my lil tricks with that kinda stuff.

if hes smart he'll remeber the specific idler i told him to use.

if not heres my answer...

i use a FLAT none flanged pully so its slightly larger then the 6rib 76mm...its all in the way they messure them.

i've always been hell bent on avoiding belt slip and so far its worked out.

i also ran my 2.7 with this set up and it worked fine so you will have the ability to go slighly larger(2.7/2.8) with out a 'belt no fit" issue.

 

How much did that cost you?

 

i think like $11.

i;ve got the box with the part number if you want it.

got it from murrys.


YOU must shave it down on your own OR go with a BilletFlow on..he machines them down for you!

your pick.

 

OK HOW DO I GET RID OF SOME OF THE RASP!?!? ITS DRIVING ME NUTS!!! I'M ON STOCK INJECTORS AND RUNNING REALLY LEAN, WILL THE 60#er HELP FIX THE EXCESSIVE RASP!?!?

 

If you don't mind me asking why would you put 60lbs injectors without uping the boost at the same time. Doing this is just a waste of time, you will have to tune your car again once you get the pulley. One other thing you said you will be running at 100% boost? We always run at 100% boost at WOT, Its limited to the pulley size so if you are running the stock pulley than your boost is not going to incress any.

 

The guy that was originally gonna tune me said these cars will put out 14 psi on stock pulley, its just limited to 12.5. I got the injectors to start, next week I'm ordering my 2.6" pulley.

 

get an actual header and if the magnaflow came with the resonator put it back on. if you cant afford a header at this moment in time put the resonator back on and see how it sounds. just a couple of suggestions.

 

I'm getting a pacesetter header, I just can't afford it right now. When I get the pacesetter I'm just getting a 3" full exhaust (cat and muffler included) and a quick time cut out infront of everything, so for the track I can have open exhaust.

 

If your running high boost, i.e me at 19lbs, and putting down some good power, the cat has to go, mine cat almost 2000deg, when me and a friend datalog my car with hp tuners. The catpipe/downpipe is the most restrictive part on our exhaust system, and iam running a 3inch exhaust setup already.

 

Hence why I deleted my cat. I can't wait for my header so I can do my cut out setup, I'm scared to blow peoples ear drums out while driving, plus it sounds like a damn honda!

 

if it makes my car run better i could care-less.

 

How does the stock pulley produce 14psi. The 3.0 pulley can only produce 14psi. Why do you think the stage 2 produces 14. If the stock pulley was capable of doing 14 than don't you think gm would save them self time and money on just making the stage 2 a tune that lets it go to full boost instead of wasting their time in making pulleys and hubs. Our stock pulleys are huge and max out at 12psi not 14.

 

you can get more then 14 lbs of boost with the stock setup. you just need a really restricted exhaust (cloged cat would do it)

Anyways, I saw this last night, and I did a before and after video when I went catless. I just didn't post them up yet.


Here we go

https://www.cobaltss.net/forums/showthread.php?p=464230#post464230

 

stock pully WILL do 14's.

they limit the car so the boost rolls on to the PCM limited 12.5lbs faster...thus more torque and more fun to drive.

the old but famious "boost by pass" stoped the PCM from bleeding that boost and leting the SC build to rite about 14lbs....it only comes at the VERY VERY top end

the reason stg2 was released is WAYYYY more then just a 3.0pully.

it gives you the higer redline and greater fuel flow and control due to the 42.5lb injecters.

the smaller pully rolls into the 14's faster thus creating the increased power sooner and for longer thanks to the ECU haveing MANY MANY ways to control boost.

 

I tried the boost bypass stock and so no increase in boost at any rpm. When i put my 2.9 without the bost bypass i saw 15psi and it never came down and when i put the boost bypass on i once agian saw no increase in boost. The boost bypass doesnt work.

I know the stage 2 is more than a pulley im not stupid but is what i was saying is if oiur cars can do 14 on a stock pulley then why would they waste there time and money by putting a new pulley in the kit.

Our peak boost numbers our limited to the size of pulley we use, so if your saying that our stock pulley can go to a max of 14psi than when you add a 3.0 pulley why doesn't the peak boost increase. The smaller the pulley not only are you going to get boost faster but your also going to get more peak.

 

Because the computer doesn't limit boost to a certain number, it limits it to a percentage. The stock pulley can make 14 psi, but it limited to whatever percent, and with the 3" pulley its limited to whatever percent that equtes to around ~15 psi. Like they guy that told about it said, "its never good to run anything at 100%".