Horsepower vs Fuel Pump Calculator E85

Fuel Pump Flow Rate Formula:

\[ \text{Flow Rate (GPH)} = \frac{\text{BSFC} \times \text{HP}}{\text{Density}} \]

Required Fuel Pump Flow Rate:

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1. What is the E85 Fuel Pump Flow Rate Calculation?

The fuel pump flow rate calculation determines the minimum gallons per hour (GPH) your fuel pump must deliver to support your engine's horsepower when running E85 fuel. This is critical because E85 requires about 30% more fuel flow than gasoline for the same horsepower.

2. How Does the Calculator Work?

The calculator uses the following equation:

\[ \text{Flow Rate (GPH)} = \frac{\text{BSFC} \times \text{HP}}{\text{Density}} \]

Where:

\( BSFC \) — Brake specific fuel consumption (typically 0.65 lb/HP-h for E85)
\( HP \) — Engine horsepower
\( Density \) — Fuel density (~6.6 lb/gal for E85)

Explanation: The equation calculates the fuel mass flow required (BSFC × HP) and converts it to volume flow by dividing by fuel density.

3. Importance of Proper Fuel Flow

Details: Insufficient fuel flow can cause lean conditions and engine damage, while excessive flow wastes energy. Proper sizing ensures optimal performance and safety.

4. Using the Calculator

Tips: Enter your engine's horsepower, typical BSFC for E85 (0.65 is a good default), and E85 density (6.6 lb/gal is standard). The calculator will determine the minimum required fuel pump flow rate.

5. Frequently Asked Questions (FAQ)

Q1: Why does E85 require more fuel flow than gasoline?
A: E85 has lower energy content per gallon (about 30% less than gasoline), so more fuel volume is needed to produce the same power.

Q2: What's a typical BSFC value for E85?
A: While gasoline engines typically have BSFC around 0.5, E85 engines usually range from 0.6-0.8 lb/HP-h due to its different combustion characteristics.

Q3: Should I add a safety margin to the calculated flow rate?
A: Yes, it's recommended to add 10-20% to the calculated value to account for pump wear, voltage fluctuations, and future power upgrades.

Q4: How does fuel pressure affect flow rate?
A: Pump flow ratings are typically at specific pressures. Higher pressure reduces flow, so ensure your pump can deliver the required flow at your system's operating pressure.

Q5: Can I use this for gasoline calculations?
A: No, use different values for gasoline (BSFC ~0.5, density ~6.0 lb/gal). The calculation method is similar but values differ significantly.