Boost?

[bullitt3350]

Does any one have a chart to show pulley size to boost ratio on a eaton.

I have a stegi v blower, looks like a 9' lower and a 2.98 (measures 3.0 across it) and my truck makes 12 psi? This seams low for the pulley sizes

 

[mcarbine]

If the face of the lower pulley measures 9" across then it is probably a 4lb pulley since they are just under 9" where the belt rides. The stock upper is a 2.93" so it sounds like your stock up top. Stock boost would be 8lb plus your 4lb lower would put you right about 12psi. If you have a CAI that should add about 1lb of boost but if you have long tubes or removed cats your boost #s would go down a tad.