Apex Supercharger sprocket question

[onrof]

does anyone know which sprockets (# teeth) combination needed for the Apex stage 2 Mountain Performance supercharger to achieve 10lbs, 14lbs and 17lbs?

I think I have two 22 tooth sprockets to make 10lbs boost.

Also what fuel system modifications are best for the fuel injection system for the extra boost? Can you simply raise the pressure? Auxilliary pump?

I've heard the stock system is only good to 12lbs with the MPI controller i already have.

 

[badluck]

I believe the MPI programmer is capable of handling the increase in fuel. But i am looking in to the boondocker setup. I found this some place on here. Not sure if it will work for you. I'll count the teeth on mine and let you know.

 

[Srxspec]

That chart is applicable only to the Stage 1 supercharger. The Stage 2 supercharger has and requires a different impeller speed.

The Stage 1 has an internal gearing from cross-shaft to the impeller of 12.67:1 and runs at a max of 150,000 impeller rpm.

The Stage 2 has an internal gearing from cross-shaft to impeller of 9.49:1 and runs at a max of 120,000 impeller rpm.

Formula for figuring out impeller speed:

Engine RPM X (Bottom Gear / Top Gear) X Supercharger Internal Gearing = Impeller Speed