i think i understand it now....with injectors the computer sends a signal to them for example at 2000rpm it will send 3 volts, and at 7000rpm (full throttle) it sends 12v. by having more resistance (14ohms) the volts that are going to the injector will be significantly less, say 5 volts at full throttle instead of the required 12v, this is because more resistance you have it will lower the volts, but not having enough resistance it will fry the ecu. So therefor you would have to find a medium, say instead of making the total resistance 7.5ohms make it 10ohms, so that the injectors can still receive an adequate amount of volts and then its just a matter of the tuner to change the volt range at differant throttle points...
SteveL do you have any rb20det injectors if so what resistance do you get with those