Injector sizing formula
injector lb/hr = horsepower × BSFC ÷ (injector count × duty cycle)
BSFC, or brake-specific fuel consumption, estimates how much fuel mass is needed per horsepower-hour. Naturally aspirated gasoline engines often use a lower BSFC assumption than boosted combinations, but actual requirements depend on the engine, fuel, tune and target air-fuel ratio.
About the cc/min conversion
The cc/min result uses an approximate gasoline conversion of 10.5 cc/min per lb/hr. Injector manufacturers may rate flow at different pressures and fuels, so always use the manufacturer’s data for final sizing.
Fuel-system sizing and tuning affect engine safety. Treat this as a planning estimate and verify injector data, base pressure, fuel type and tuning requirements.