Fuel Injector Flow Calculator
Fuel Injector Flow
Calculate the required fuel injector size based on engine horsepower, number of cylinders, and fuel type
hp
%
Formula
Injector Size = (HP x BSFC / Cylinders / Duty Cycle) x 10.5
Frequently Asked Questions
How do I size fuel injectors?
Divide total fuel demand by the number of cylinders, then account for maximum duty cycle (typically 80%).
What duty cycle should fuel injectors run at?
Most tuners recommend a maximum of 80% duty cycle to allow headroom for fuel pressure changes and safety.