What size is the pulley you're using on the supercharger, and how many pounds of boost are you making?

I've got what was supposed to be a pulley that would make 8 lbs of boost, I was told, and I'm only seeing about 4-5 lbs.

Thanks

Collin

 

The 8 lb pulley over spins the supercharger. The larger pulley makes less boost but doesn't over spin it. That supercharger is sized very wrong for the rotary so lots of compromises needed to be made.

 

http://pbgarrott.tripod.com/Garrott.html
http://www.geocities.com/boatseason/rx7.html

 

What I've heard is that the 12lb pulley overspins the supercharger, and the 8lb pulley is what people changed to to avoid overspinning. The 3-4lb pulley I have now is not one that I've ever seen documentation of anyone using with the kit.

 

I guess what I really need is to figure out whether the pulley is measured by the outermost diameter of the thing, or the diameter of the inside of the tread.

 

You don't measure a pulley diameter from the bottom of the rib valleys. You measure the diameter from the top of them. Yours should be at least 3.75" in diameter at the smallest. They came with a very small 3.25" pulley.