The inputs are beginning and ending RPM, RPM step, dwell angle in crankshaft degrees, resistance of primary ignition coil circuit in ohms, inductance of ignition coil primary in milliHenries (mH), battery voltage, and capacitance of ignition coil secondary in picoFarads (pF). This model assumes 100% energy transfer from primary circuit to secondary circuit, which will not be the case in the real world - expect 70-85%.
The interesting thing here is to see how the secondary voltage drops off at higher RPM because there is less time to "charge" up the ignition coil primary. You can jack up the dwell angle, which will allow more time for the coil to charge, but then the peak primary current rises at lower RPM, and the more current the more heat generated in the coil, which is not good either (generically, coils like 10 amps or less). Play with the values and see what you can come up with - maybe you can design the next super-duper coil!