1. What is Belt Pulley Ratio?

The belt pulley ratio determines the speed relationship between the engine and accessory components in a car. It's calculated by dividing the diameter of the engine pulley by the diameter of the accessory pulley.

2. How Does the Calculator Work?

The calculator uses the pulley ratio equation:

Where:

• \( Engine\ Pulley \) — Diameter of the engine pulley (mm)
• \( Accessory\ Pulley \) — Diameter of the accessory pulley (mm)

Explanation: The ratio determines how many times the accessory rotates for each rotation of the engine. A ratio greater than 1 means the accessory spins faster than the engine.

3. Importance of Pulley Ratio

Details: Proper pulley ratio is crucial for optimal performance of accessories like alternators, water pumps, and superchargers. Incorrect ratios can lead to underperformance or premature wear.

4. Using the Calculator

Tips: Measure both pulleys accurately in millimeters. Enter the values to determine their speed relationship. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical pulley ratio for alternators?
A: Most alternators have ratios between 2:1 and 3:1, meaning they spin 2-3 times faster than the engine.

Q2: How does pulley ratio affect superchargers?
A: Higher ratios make the supercharger spin faster, creating more boost but requiring more engine power.

Q3: Can I use inches instead of millimeters?
A: Yes, as long as both measurements use the same units, the ratio will be correct.

Q4: What happens if my ratio is too high?
A: Accessories may overspeed, causing premature bearing failure or other damage.

Q5: How does ratio affect belt life?
A: Extreme ratios (either very high or very low) can reduce belt life due to increased stress and heat.