1. What is Crank Horsepower (CHP)?

Definition: Crank Horsepower, also known as brake horsepower (BHP), is the power measured at the engine's crankshaft before drivetrain losses.

Purpose: This calculator converts wheel horsepower (measured at the wheels) to crank horsepower by accounting for drivetrain losses.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( CHP \) — Crank Horsepower (hp)
• \( WHP \) — Wheel Horsepower (hp)
• \( DTL \) — Drivetrain Loss factor (typically 0.10-0.15 for RWD, 0.15-0.20 for FWD/AWD)

Explanation: The formula accounts for power lost between the engine and wheels through the drivetrain components.

3. Importance of CHP Calculation

Details: Knowing crank horsepower helps compare engine performance across different vehicles and drivetrain configurations.

4. Using the Calculator

Tips: Enter your measured wheel horsepower and estimated drivetrain loss (default 0.15 for 15% loss). DTL must be between 0 and 0.5 (50%).

5. Frequently Asked Questions (FAQ)

Q1: What's a typical drivetrain loss percentage?
A: Typically 10-20%: ~15% for RWD, ~18% for FWD, and ~20% for AWD vehicles.

Q2: Why is WHP lower than CHP?
A: Power is lost through the transmission, differential, axles, and other drivetrain components.

Q3: How accurate is this calculation?
A: It provides a good estimate, but actual losses vary based on drivetrain condition, temperature, and other factors.

Q4: Can I use this for electric vehicles?
A: EV drivetrain losses are typically lower (5-10%) due to fewer moving parts.

Q5: Where can I measure WHP?
A: WHP is measured on a dynamometer (dyno) at the wheels.