Modern Automotive Performance
Modern Automotive Performance


{literal} {/literal} {literal} {/literal} {literal} {/literal} {literal} {/literal}

Fuel Injector Calculator

Looking to build a car with serious power, and turn heads on the street and strip or racetrack? You need to know the correct sized fuel injector that will get you there. What's the most important component in a racecar? Not the turbo, not the engine, and not the suspension. It's the fuel delivery system.

Fuel injectors are one of the most important pieces of the puzzle in building a fast car. Without correctly sized injectors, the car wont be able to make max power, and in some cases it wont run at all. It may even do damage if inadequate fuel enters the engine under heavy load. When shopping for fuel injectors, you want to consider the flow rates / pressure, impedance, and connection type

  • Flow Rate / PSI - Referred to in CC (cubic centimeters), this is how much fuel the injector will move over 1 minute.
  • Impedance - Simply put, it's the electrical resistance of the injector. Low impedance injectors are used on high performance applications, where high impedance injectors are commonly used on stock applications.
  • Connection Type - Some injectors are universal and must be crimped into the ECU harness to operation, where others are available with plug-and-play connections for simple installations.

We've built this handy Fuel Injector sizing calculator to help you determine how much flow you'll need. Simply enter your goal crank horsepower goal, the number of injectors (cylinders) your engine has, the correct number based on aspiration of your engine, and goal PSI at the rail.

Have any questions about a specific number, or unsure how to use the calculator? Feel free to contact us today for assistance, and we'll take the stress out of the fuel delivery aspect of your build!

help finding injectors

Fuel Injector Calculator

Crankshaft Horsepower (BHP):

Number of Injectors:

Brake Specific Fuel Consumption Desired:

   .45 to .50 for N/A Engines,
   .55 TO .60 for Supercharged engines,
   .60 to .65 for Turbocharged engines.

Maximum Injector Duty Cycle:

   Warning: Duty cycle should not exceed 80% (0.80) for
   these calculations.

Fuel System Pressure at Rail (PSI):

buy fuel injectors

Injector Required @ Test PSI

  Lbs/Hr      CC/Min