1. What is the Horsepower to Torque Equation?

Definition: This equation calculates the torque produced by an engine based on its horsepower and rotational speed (RPM).

Purpose: It helps automotive engineers, mechanics, and enthusiasts understand engine performance characteristics.

2. How Does the Equation Work?

The equation uses the formula:

Where:

• \( T \) — Torque (pound-feet)
• \( HP \) — Horsepower
• \( RPM \) — Revolutions per minute
• 5252 — Conversion constant (derived from the relationship between HP, torque, and RPM)

Explanation: The formula shows that torque and horsepower are directly related through engine speed. At 5252 RPM, horsepower and torque values are equal.

3. Importance of Torque Calculation

Details: Torque measures rotational force and determines a vehicle's acceleration and towing capacity. Understanding this relationship helps in engine tuning and performance analysis.

4. Using the Calculator

Tips: Enter the engine's horsepower and RPM values. Both must be greater than zero for calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why is 5252 the magic number in this equation?
A: 5252 comes from the conversion between foot-pounds per minute and horsepower (1 HP = 550 ft-lb/sec = 33,000 ft-lb/min, and 33,000/2π ≈ 5252).

Q2: What's more important - horsepower or torque?
A: Both are important but measure different things. Horsepower determines top speed, while torque determines acceleration and pulling power.

Q3: Do electric motors follow this equation?
A: Yes, but electric motors often produce maximum torque at zero RPM, which this equation can't show.

Q4: How does gear ratio affect torque?
A: Gearing multiplies torque (while reducing RPM), but the fundamental relationship between engine torque and horsepower remains.

Q5: What's typical torque for a passenger car?
A: Most passenger cars produce 100-300 lb-ft of torque, with trucks and performance vehicles often exceeding this range.