in general -
any two different injectors, even if they flow the same amount of fuel per unit of time, have different characteristics such as latencies, voltage compensations, etc. it is also possible that the sp1 and sp2 injectors have different flow rates, resulting in different scalings.
ultimately, these sorts of things can be adjusted for. i'm not familiar with how robust the powercommander is in compensating for injectors, but it is not entirely accurate to say that injector X won't work for an application. more precisely is whether or not you or your tuner can make injector X work for your application.
the serious commuter, featured on the rogue website homepage.
also - Evo IX, E85, ecu controlled boost, and too much front camber for sensible street use!