1. What is a Crank vs Wheel HP Calculator?

Definition: This calculator estimates engine (crank) horsepower based on measured wheel horsepower and drivetrain loss factor.

Purpose: It helps automotive enthusiasts and professionals understand the relationship between engine output and actual power delivered to the wheels.

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 0.10-0.25)

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

3. Importance of Crank vs Wheel HP Calculation

Details: Understanding this relationship helps in vehicle performance tuning, comparing dyno results, and verifying manufacturer power claims.

4. Using the Calculator

Tips: Enter your measured wheel horsepower and drivetrain loss factor (default 0.15 for RWD cars). DTL must be between 0 and 0.5.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical drivetrain loss factor?
A: Typically 10-15% for RWD (0.10-0.15), 15-20% for FWD (0.15-0.20), and 20-25% for AWD (0.20-0.25).

Q2: Why is wheel HP less than crank HP?
A: Power is lost through the drivetrain components (transmission, differential, axles) before reaching the wheels.

Q3: How do I measure wheel horsepower?
A: Use a chassis dynamometer (dyno) at a performance shop or tuning facility.

Q4: Does this account for all power losses?
A: This is a simplified model - actual losses can vary with temperature, lubrication, and drivetrain condition.

Q5: Can I use this for motorcycles?
A: Yes, but motorcycle drivetrain losses are typically lower (5-10% or 0.05-0.10 factor).