Calculation for injector size

Calculations are with 3bar fuel pressure.

BSFC(Brake Specific Fuel Consumption) is usually a value between 0.4 and 0.7 for gasolineengines. BSFC can be calculated, best way to find out is to do it in a engine dyno. If engine dyno is not available you can use following values:

For naturally aspirated BSFC 0,4 to 0,5
For Turboengines BSFC 0,6 to 0,7
For Rotary engines BSFC 0,6 to 0,7
For E85 fuel, add to value about 0,15
For Turbocharged Methanol engine 1,2 to 1,4

Injector duty cycle is injector opening time. Never tune an engine higher than 90% dc even if an inctor can be open 100%. There is an reserve needed if for example weather gets colder or higher barometric pressure.

Flow converter :

Calculate flow of fuel pump you need for your injectors

Calculation is with vacuum to fuel pressure regulator
10% safety factor is included for losses in fuel lines
Result is recomended minimum flow needed to max out the injectors
Think about battery voltage when chosing pump

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BJP Race have since 2008 provided customers with high quality fuel injectors, pumps and more for fuel system and electrical systems. For both racing veichles and standard cars. We behind BJP Race have many years of experience of motorsport and is something we love! We can help with most things in these areas thru our webshop, mail, phone or if you want to visit our workshop/warehouse.

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