1. What Is Flywheel Horsepower?

Flywheel horsepower (also known as engine horsepower or brake horsepower) is the power output measured directly at the engine's flywheel, before any drivetrain losses. This represents the true power potential of the engine itself.

2. How Does The Calculator Work?

The calculator uses the flywheel HP formula:

Where:

• \( Rear\ Wheel\ HP \) — Power measured at the wheels (hp)
• \( Drivetrain\ Efficiency \) — Efficiency factor accounting for power loss (0-1)

Explanation: The formula calculates engine power by accounting for drivetrain losses that occur between the engine and wheels.

3. Importance Of Flywheel HP Calculation

Details: Understanding flywheel horsepower is crucial for engine performance analysis, vehicle comparisons, and tuning modifications. It provides a standardized way to compare engine power across different vehicles and drivetrain configurations.

4. Using The Calculator

Tips: Enter measured rear wheel horsepower and drivetrain efficiency (typically 0.85 for rear-wheel drive, 0.80 for front-wheel drive, 0.75 for all-wheel drive). All values must be valid (HP > 0, efficiency between 0.01-1).

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between flywheel HP and wheel HP?
A: Flywheel HP is measured at the engine output, while wheel HP is measured at the wheels after drivetrain losses. Wheel HP is typically 15-25% lower than flywheel HP.

Q2: What are typical drivetrain efficiency values?
A: Rear-wheel drive: 0.85-0.88, Front-wheel drive: 0.78-0.82, All-wheel drive: 0.72-0.78 depending on the specific drivetrain design.

Q3: Why is wheel HP lower than flywheel HP?
A: Power is lost through the transmission, driveshaft, differential, and other drivetrain components due to friction and mechanical inefficiencies.

Q4: Can this calculator be used for all vehicle types?
A: Yes, but ensure you use the appropriate drivetrain efficiency value for your specific vehicle configuration (RWD, FWD, or AWD).

Q5: How accurate is this calculation?
A: The calculation provides a good estimate, but actual drivetrain losses can vary based on vehicle condition, temperature, and specific component design.