Fuel Injector Flow Rate & Duty CycleAutomotive & Vehicles

Fuel Injector Flow Rate (cc/min & lb/hr) Sizing Calculator (HP & Duty Cycle)

Calculate required fuel injector flow rate in cc/min and lb/hr per injector for target engine horsepower, naturally aspirated vs turbocharged induction (BSFC), safe 85% duty cycle, and E85 ethanol compatibility.

Calculated Result

Required Injector Flow Rate (cc/min)

670cc/min

Calculator Inputs

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Required Injector Flow Rate (cc/min)

670cc/min

Injector Flow Rate in Pounds per Hour (lb/hr)

63.8 lb/hr

Required Injector Flow Rate for E85 Fuel (cc/min)

871 cc/min (E85)

Injector Sizing Comparison: Standard Gasoline vs E85 Ethanol (cc/min)

Gasoline Injector Size
670 cc/min(43%)
E85 Injector Size
871 cc/min(57%)

Standard internal combustion tuning formula compliant with Bosch Motorsport, DeatschWerks, and Injector Dynamics engineering standards.

This calculator is designed for educational and informational purposes based on publicly declared statutory frameworks. The outputs do not constitute binding financial, tax, or legal advice. We assume no liability for decisions made based on these estimates. Always verify with the relevant official authorities or a certified professional advisor.

Calculation Methodology

Flow Rate (lb/hr) = (Crank HP * BSFC * Fuel Multiplier) / (Number of Cylinders * (Duty Cycle / 100)). Flow Rate (cc/min) = lb/hr * 10.5. BSFC: Naturally Aspirated = 0.50, Turbocharged = 0.62. E85 multiplier = 1.30.

Frequently Asked Questions

Tuning professionals recommend keeping peak injector duty cycle at or below 80% to 85% to ensure reliable solenoid opening/closing and avoid running static lean.

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