for boosted motors at minimum requirement (target horsepower x 0.6 ) / (number of injectors x 0.8 ) = required fuel in lb/hr lb/hr x 10.50 = required fuel in cc/min
When working backwards, a quick formula is: (Injector CC) / 5 x (No cylinders) = Crank H/P your injectors can support. (Crank H/P) / 1.34 = Kilowatt at flywheel, which is roughly what you will get at wheels in a RWD, so you will get a fraction higher in a FWD.