CPR Racing Injector Calculator

Estimate injector flow changes based on fuel pressure, convert between CC/min and lb/hr, and calculate injector size for horsepower goals.

1. Fuel Injector Flow vs Pressure

Formula:

New Flow = Rated Flow × √(New Pressure ÷ Base Pressure)

2. CC/min to lb/hr

Formula: lb/hr = CC/min ÷ 10.5

3. lb/hr to CC/min

Formula: CC/min = lb/hr × 10.5

4. Injector Sizing by Horsepower

Formula: Injector Size = HP × BSFC ÷ Injectors ÷ Duty Cycle

Typical BSFC: Naturally Aspirated 0.45–0.55 | Turbo/Supercharged 0.60–0.75 | Recommended max duty cycle: 80%.

CPR Racing — Total Fuel Systems
Injector Testing • Cleaning • Flow Matching • Full Motorsports Characterization