Injector Flow at New Pressure Calculator

When to use it

• Compare how a change in rated injector flow affects new injector flow before committing to parts, setup, or strategy changes.
• Check a workshop, dyno, simulator, or trackside spreadsheet result using a transparent formula: Rated flow × √(new pressure ÷ rated pressure).
• Use the result with known fuel density, measured fuel pressure, realistic duty-cycle limits, and logged lambda data. Fuel systems should be sized with headroom because demand changes with boost, temperature, fuel type, and engine safety targets.

How to use it

1. Enter rated injector flow in cc/min; the default value shown is 1,000 cc/min.
2. Enter rated differential pressure in bar; the default value shown is 3 bar.
3. Enter new differential pressure in bar; the default value shown is 4 bar.

How to read the result

New injector flow is shown in cc/min. Use the number as a calculated reference point, then compare it with measured data from the car, the part supplier, or the race environment. A mathematically clean answer can still be unsuitable if the inputs are estimated, rounded, measured under different conditions, or outside the normal range for the vehicle.

Assumptions and checks

• The calculator applies the displayed formula directly and assumes the entered rated injector flow, rated differential pressure, and new differential pressure are valid for the vehicle and conditions being considered.
• Changing rated injector flow and rated differential pressure together can move the answer in ways that are easy to miss, so make related setup changes deliberately.
• Confirm the fuel type and density when converting between mass flow and volume flow.
• Keep injector duty cycle and pump capacity below their practical limits with a sensible reserve.
• Verify fuelling changes on proper measuring equipment before relying on them at full load.