1. What is a Wheel to Crank Horsepower Calculator?

Definition: This calculator estimates the engine's crank horsepower (CHP) based on measured wheel horsepower (WHP) and drivetrain loss factor.

Purpose: It helps automotive enthusiasts and professionals estimate engine power from dyno measurements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( CHP \) — Crank horsepower (engine output)
• \( WHP \) — Wheel horsepower (measured at wheels)
• \( DTL \) — Drivetrain loss factor (typically 0.12-0.15 for RWD)

Explanation: The formula accounts for power lost through the drivetrain (transmission, differential, etc.) to estimate the engine's actual output.

3. Importance of Crank Horsepower Calculation

Details: Understanding crank horsepower helps in engine performance analysis, tuning, and comparing different vehicles on equal terms.

4. Using the Calculator

Tips: Enter your dyno-measured wheel horsepower and drivetrain loss factor (default 0.15). DTL must be between 0 and 0.5 (typically 0.12-0.20).

5. Frequently Asked Questions (FAQ)

Q1: What's a typical drivetrain loss factor?
A: Typically 12-15% (0.12-0.15) for RWD, 15-20% for FWD/AWD vehicles.

Q2: Why not just measure engine power directly?
A: Engine dynos are expensive and uncommon; wheel dynos are more accessible for most tuners.

Q3: Does this work for all vehicle types?
A: Yes, but the DTL factor varies by drivetrain (higher for AWD, lower for RWD).

Q4: How accurate is this calculation?
A: It's an estimate - actual drivetrain loss can vary based on many factors.

Q5: What if I don't know my drivetrain loss?
A: Use 0.15 (15%) as a reasonable default for most RWD vehicles.