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!

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Flow Calculator

Looking for 500 horsepower to the rear wheels? How about 1000 horsepower at the crankshaft? You can determine what size fuel injectors you will need by entering a few simple details into our calculator. Explanations of each input are below the calculator.

The inputs are, in order of appearance:

The number of cylinders in your engine,

The BASE* fuel pressure you will run (your fuel pressure at idle), *our calculator assumes a 1:1 rising rate fuel pressure regulator for turbo applications

Engine aspiration, {Turbocharged, Supercharged, and Naturally Aspirated engines have different BSFC’s (see Glossary of Terms for definitions)}

Desired horsepower, (The amount of power you desire directly affects the amount of fuel you will need to achieve your goal.)

Maximum injector duty cycle (IDC) (In order to be conservative, Fuel Injector Clinic recommends a maximum duty cycle of 90%.)

 

Horsepower desired
Injector Size Required
Fuel Type cc/min lb/hr
Gasonline    
E85