What is the function of the MSD card on the supercharger?

 

Are you talking about the blue MSD Box that often shipped with older JRSC Kits? If so, that is a piggyback timing controller that pulls timing based on boost. IIRC, it will pull a total of 6 degrees of timing, starting at about 4 lbs. of boost. That one does nothing to handle fuel, it just deals with timing.

If you are not talking about that one, can you share a little more info about which you are asking about?

-Jac