1. What is Supercharger Pulley Ratio?

The supercharger pulley ratio determines the speed relationship between the engine crankshaft and the supercharger. It indicates how many times faster the supercharger spins compared to the engine crankshaft.

2. How Does the Calculator Work?

The calculator uses the pulley ratio formula:

Where:

• Crank Pulley — Diameter of the crankshaft pulley (inches)
• Supercharger Pulley — Diameter of the supercharger pulley (inches)

Explanation: The ratio shows how many revolutions the supercharger makes for each revolution of the crankshaft. A higher ratio means the supercharger spins faster relative to engine speed.

3. Importance of Pulley Ratio Calculation

Details: Proper pulley ratio calculation is crucial for optimizing supercharger performance, preventing overspeeding damage, and achieving desired boost levels in forced induction systems.

4. Using the Calculator

Tips: Enter both pulley diameters in inches. All values must be valid positive numbers. The calculator will compute the ratio of crankshaft pulley to supercharger pulley.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical supercharger pulley ratio?
A: Typical ratios range from 2:1 to 4:1, depending on the supercharger type and desired boost levels.

Q2: How does pulley ratio affect boost pressure?
A: Higher ratios (smaller supercharger pulley or larger crank pulley) increase supercharger speed, resulting in higher boost pressure.

Q3: What are the risks of too high a pulley ratio?
A: Excessive ratios can cause supercharger overspeed, leading to bearing failure, rotor damage, or catastrophic supercharger failure.

Q4: Can I use this calculator for different measurement units?
A: This calculator uses inches. Convert other units to inches first (1 inch = 25.4 mm) for accurate results.

Q5: How does pulley ratio relate to belt slip?
A: Higher ratios increase belt tension requirements and may cause belt slip if not properly tensioned or if using inadequate belt systems.