First off, I'm a J-body Driver. However, I am supercharged with the GM Charger.

I have a few uncertainties about smaller pullies and such.

How small of a pulley can the 'stock' tensioner accomadate without slipping issues?

How small of a pulley can the 36lb injectors safely fuel?
The tune isn't an issue, I would have HPtuners before upgrading my pulley size.

The 2.5 bar map sensor can read ~22 psi of boost? I'd be happy with 15.
Any tuning or mechanical issues with using a smaller pulley with a ported and aftercooled supercharger?

I know it's a lot of questions; I had more, but I forgot them as I was typing.
Thanks for any replies.

 

Also: What boost difference is there between the 3.0" and 3.1" pullies?

Injector Duty Cycle for each?

Thanks.

 

I have a 2.6 with a stage 2 belt and no slippage. I have read people have put a 3.0 pulley on stock injectors that is roughly 15lbs. I would prolly recommend 42's to be safe because in gm's stage to kit gives you 3.0 i beliece that is size, 42.5's, smaller belt, and a reflash tune. Anyone else correct me if I am wrong.

 

Thanks for the reply blown06.
I've rethought my questions; Here's the revised version:

I want a smaller pulley for my M62.

What boost difference is there between the 3.0" and 3.1" pullies?

How small of a pulley can the 'stock' tensioner accomadate without slipping issues?

What would be a good fuel injector size to accomodate down to a 2.85" pulley?

What boost would be seen with a 2.85" pulley?

Is there an equation to figure this out?

Anyone dyno with a 3" or 2.85" pulley?

 

good questions. I'd try the performance forum or better yet post those questions on the redline forum you will get good solid answers.

 

check my updates

 

Related idea:
What is required to change the pully from a 3.34" to something else? Pulley puller, new pulley...anything else?

 

You said you have a J-body - what engine are you running this on? Also, and maybe someone else can chip in on this, but different engines can have different-sized crankshaft pullies, which would in turn affect how fast your s/c spins with any given pulley. If you have an engine with a smaller crankshaft pulley than the LSJ, then you won't spin the s/c as fast with the same size pulley.

As for injectors, it's not so much a boost issue as an hp issue. 36lb should be good to over 200whp, and 42.5 can get you in the 250 whp range, depending on drivetrain loss, etc. How much boost it takes to get you there is a whole other story.

As for changing the 3.34", if it's the same as ours on the LSJ, you'll need a pulley puller to get it off, and a pulley installer tool to get the new one on. You can replace it with a modular pulley system, which is just a ring that will take many different sizes of pullies, with just a few screws to change.