Unlock your engine's true potential with our Fuel Injector Flow Rate & Duty Cycle Calculator. Precisely determine the ideal injector size needed for your target horsepower and evaluate the duty cycle of your current setup to ensure optimal fuel delivery and avoid engine damage. Essential for tuners, enthusiasts, and performance builders.
Formula:
Formulas Used:
1. Required Injector Flow Rate (per injector, lb/hr):
Flow Rate (lb/hr) = (Target HP × BSFC) / (Number of Injectors × Max Duty Cycle)
2. Calculated Actual Duty Cycle (%):
Duty Cycle (%) = ((Target HP × BSFC) / (Number of Injectors × Actual Injector Flow Rate (lb/hr))) × 100
Variable Definitions:
- Target HP: Your engine's estimated target horsepower.
- BSFC (Brake Specific Fuel Consumption): Fuel consumption rate relative to power output (e.g., 0.45-0.55 for NA, 0.6-0.7 for Forced Induction).
- Number of Injectors: Total number of fuel injectors in your engine (usually matches cylinder count).
- Max Duty Cycle: The maximum safe operating duty cycle for your injectors (expressed as a decimal, e.g., 0.8 for 80%). We recommend staying below 80-85% for longevity and precise control.
- Actual Injector Flow Rate (lb/hr): The rated flow rate of your specific injectors in pounds per hour (lb/hr). If input in cc/min, it will be converted internally (1 lb/hr ≈ 10.5 cc/min).