What most people don't understand is that the volt boosters are there to improve the IGNITION SYSTEM, more than the fuel system. If you choose the right fuel pump, feeds and injectors, you will be OK with 12 volts even. But, the ignition system benefits most of all with higher system voltage. There is a HUGE difference running the CCCI at 6000 RPM, between 11 volts and 15 volts. Huge. The typical GN engine will log a decrease in available voltage at high RPM's as compared to low RPM's. The ignition system needs all the voltage it can get.