Does anybody know how big the stage II pulley is from GM?

 

77.9 MM or just a tadd over 3 inches

The internet says that's 3.07 inches...

 

yeah it says 3" but its in reality like 3.07 or something

 

I was wondering because the Gm stage 3 pulley is 76mm. I have the GM Stage 2 kit and an AEM cold air intake on my 06 ss/sc. If I just install the 76 mm pulley, do you think that will cause me any problems??

 

You should be fine.

 

Do it right the first time. To many people just put a smaller pulley on without a tune, or without the proper preperation. When running a smaller pulley you need bigger injectors. Just install your stage II and take it to the dealer for the Stage II reflash. Don't boost untill you have the reflash/tune. Trust me, doing it right the first time will save you lots of money down the road.

 

Rally, I think he does have the Stage II installed. Anyways, kenhebe, I think you should be perfectly fine with the Stage III 2.9" pulley. You'll always get more power out of a custom tune if it's done correctly, but for all intents and purposes, GM thinks it's fine to run a 2.9" on the Stage II tune. Just remember, they don't warranty it...

 

Good point.

 

Sorry about that earlier post lol. Yea, smaller pulley would be sweet. I want to get the 2.79 with a good tune from hp tunners one day. If anything goes wrong, just stick the gm 3.07" pulley back on and get it to the stealership.

 

How much of a gain do you think I should get with this pulley. Again I already have stage II and an AEM intake. I was thinking maybe 2lbs of boost/ 5HP?

 

You really won't see much H.P. increase with something like this. The great thing about dropping the pulley just a little is you should see a great torque increase. Don't bother putting numbers on anything as far as gains go cause every car is different. The main thing is that you can do this safely and it will improve performance...

EDIT: If you want to know gains, you have to dyno before/after. Don't worry too much about that. The real numbers you should worry about should be at the track.

 

Well, I went ahead and ordered it. It should be here mid-late next week. I will let oyu know how it turns out. I appreciate all the input. I'll take more if you got it.

 

I recommend getting dyno tuned. Not really necessary, but from what I've read, a lot of tuners get some decent power by cleaning up GM's sloppy tune. I've also heard it can help drivability as well. It's all "hear-say" but reputable "hear-say" at that. If you know someone with a dyno and HPT, you can't go wrong!

 

Where did you order and how much? I was interested in this as well.

 

I manage a collision center in Texas so I got it from a Chevy dealer at cost. I paid 88.73 with tax. You can go to www.crateenginedepot.com and get the pulley there. Click on cobalt performance parts then stage kits. It will be on the second page.

 

thanks, i was gettin hooked from my bro but he just quit workin for gm.