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Fuel Injector Size

(Required Fuel Injector Size Calculator)

Calculator Description:

This calculator will help you determine how large of a fuel injector your engine will require. By entering a few known variables we can calculate the size of fuel injector you should be using.

The Fuel pressure is also accounted for, your running observed pressure and the manufacturer’s factory pressure.

NOTE: The manufacturer's flow rate is based on a set rail pressure, this is typically 43.5psig(3bar); however there are several which are different, like fords rail pressure is based on 29lbs. This is NOT the injector rated flow rate. IE: 19lbs/hr). This is a simple calculator and there are several factors involved that should always be double-checked. Please use at your own risk.

USER INPUTS

(Fill out the following information and then click the Calculate Required Injector Size button below.)

Desired Crank HP (BHP) Enter your maximum ESTIMATED Crank horse you expect to achieve with your engine. Click for more detailed Help.

Number of Injectors Enter your maximum ESTIMATED Crank horse you expect to achieve with your engine. Click for more detailed Help.

Brake Specific Fuel Consumption (BSFC):

 Natural Asperated Supercharged Turbo

 BSFC Brake Specific Fuel Consumption (BSFC) is a measure of fuel efficiency within a shaft reciprocating engine. It is the rate of fuel consumption divided by the power produced. Click for more detailed Help.

Maximum Injector Duty Cycle % WARNING! Should NOT Exceed 80%. The extra 20% is your safty margin. You always need a safty margin. Click for more detailed Help.

Runing Fuel Rail Pressure PSIG What your fuel pressure will be set at on your fuel rail. Car running, no vacuum on regulator. WARNING: Should not exceed 15% plus or minus from the Manufacturer Fuel Rail Pressure. Click for more detailed Help.

Manufacturer Fuel Rail Pressure PSIG Factory Fuel Rail Pressure. From the factory every fuel injector is rated for flow in lbs/hr or cc. In calculating actual fuel delivery it is important to know what rail pressure the Manufacturer used when rating their injectors. Click for more detailed Help.

 

Results are Below

RESULTS

Required Injector Size

  Lbs/Hr or      CC/Min

Required Injector Size Results in Readable format:

Using () fuel injectors with a flow rate of lbs/hr will allow a naturally aspirated engine to produce BHP.

NOTE: Calculations based on fuel rail pressure set at psi on a fuel injector rated at lbs/hr with psi fuel rail pressure.

Producing this amount of BHP with these injectors will use % of their maximum injector duty cycle.

Required fuel injector size calculator v0.1, copyright 2011

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