Ok, heres the story. I have an '03 Silverado SS LQ9 and a Radix in my '94 Caprice. All is well, and I decide to order a smaller pulley and do some tuning. I first order a pulley from PulleyBoys, I get it, install it, and when tightened, the pulley sits too far back on the supercharger, visibly pulling the belt back, and when I start the car the belt is squeeling like crazy. I take a hardened washer that I have laying around, throw it in behind the pulley, pulley comes out a bit past the acessories, belt is making some dust and squeek when cold, but its driveable. I then call Pulleyboys, and its the first time they hear of such a problem. I then send them my original 3.3 pulley, and they measure it to be 40 thousandths difference in the offset. I then figure i should order one from magnacharger and not have any more problems. I call up Magnacharger and order a 2.9 pulley from David. I get the pulley, put it on, and end up with the same exact problem. When I call David, he said there is only one size pulley and that maybe theres something wrong with the supercharger. I am sending him my 3.3 original pulley so he can take a look at it.

Does anyone have any ideas as to what is going on here? Its driving me crazy. I drive the car every day, its making 7PSI with the 2.9 pulley, and no foreign noises from the supercharger.


Heres a shot of the car

 

sounds like you just need to get the offset sorted and you'll be good to go

 

I can have the right shim made, or the right pulley machined by pulleyboys, but should the question why bother me or just forget about it bolt the pulley on and go?

 

Did you try to turn the pulley boys around. I know the jack shaft pulley's are offset different one side from another. The Magnuson Pulley's are always labled on the side that goes out, the pulley boys pulley's are not labled.

 

I had a similiar problem with mine. They machined it backwards to where the stout went in backwards and it lined up. Sent it back and the next one worked perfect. I hope they get it right for you. That has to be one fast car.
Shawn

 

The pulley I use now is from magnacharger, and writing is facing out

 

After 2 pulleys from different companies, what are the chances of both being machined backwards?

 

Possible, but doubtful. 3 times a charm?

 

I would shim it and call it a day. This way whenever you change pulley sizes again you just keep the same shim. My new 8 groove pulley has .030 shim on it to correct the alignment. I would rather shim it then have to cut a pulley down each time I wanted to change sizes. You could send the supercharger back in but it is hard on a daily driver.