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Injector Flow Rate Pressure Calculator

Injector Flow Rate Equation:

\[ Q2 = Q1 \times \sqrt{\frac{P2}{P1}} \]

cc/min
psi
psi

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1. What is the Injector Flow Rate Pressure Equation?

The injector flow rate pressure equation calculates the new flow rate (Q2) of a fuel injector when operating at a different pressure (P2) than its rated pressure (P1). This is based on the principle that flow rate is proportional to the square root of pressure.

2. How Does the Calculator Work?

The calculator uses the injector flow rate equation:

\[ Q2 = Q1 \times \sqrt{\frac{P2}{P1}} \]

Where:

Explanation: The equation shows that flow rate increases with the square root of pressure ratio. Doubling the pressure increases flow by approximately 41% (√2 ≈ 1.414).

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculation is crucial for fuel system tuning, ensuring proper fuel delivery, preventing lean or rich conditions, and optimizing engine performance across different operating pressures.

4. Using the Calculator

Tips: Enter the injector's rated flow rate in cc/min, the rated pressure in psi, and the new operating pressure in psi. All values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Why does flow rate change with pressure?
A: Flow rate is proportional to the square root of pressure because of the Bernoulli principle and fluid dynamics through the injector nozzle.

Q2: What are typical injector flow rates?
A: Flow rates vary from 150-2000+ cc/min depending on injector type and application, with most automotive injectors ranging from 200-800 cc/min.

Q3: What pressure units should I use?
A: The calculator uses psi (pounds per square inch), which is the standard unit for fuel pressure measurement in automotive applications.

Q4: Does this equation work for all injector types?
A: This equation applies to most conventional fuel injectors, but may have limitations with some specialized injector designs or extreme pressure ranges.

Q5: How accurate is this calculation?
A: The calculation provides a good theoretical estimate, but actual flow rates can vary slightly due to injector design, fuel viscosity, and other factors.

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