Vortech Impeller Speed Calculator

Impeller Speed Formula:

\[ \text{Impeller Speed} = \text{Engine RPM} \times \left(\frac{\text{Crank Pulley}}{\text{Supercharger Pulley}}\right) \times \text{Step Up Ratio} \]

Engine RPM (rpm):

rpm

Crank Pulley (in):

inches

Supercharger Pulley (in):

inches

Step Up Ratio (decimal):

Impeller Speed (rpm):

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1. What is Impeller Speed?

Impeller speed is the rotational speed of the supercharger's impeller, which directly affects the boost pressure and efficiency of the supercharger system. For Vortech superchargers, maintaining the proper impeller speed is crucial for optimal performance and reliability.

2. How Does the Calculator Work?

The calculator uses the following formula:

\[ \text{Impeller Speed} = \text{Engine RPM} \times \left(\frac{\text{Crank Pulley}}{\text{Supercharger Pulley}}\right) \times \text{Step Up Ratio} \]

Where:

Engine RPM — Engine revolutions per minute
Crank Pulley — Diameter of the crankshaft pulley (inches)
Supercharger Pulley — Diameter of the supercharger pulley (inches)
Step Up Ratio — Internal gear ratio of the supercharger (typically 3.47:1 or 3.60:1 for Vortech)

Explanation: The formula calculates how fast the impeller is spinning based on engine speed and pulley ratios.

3. Importance of Impeller Speed Calculation

Details: Knowing your impeller speed helps ensure you're not overspeeding your supercharger (which can cause damage) or underspeeding it (which reduces boost potential). Vortech typically recommends keeping impeller speeds below 55,000 rpm for most models.

4. Using the Calculator

Tips: Enter your engine's maximum RPM, the diameters of both pulleys, and your supercharger's step-up ratio. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical step-up ratio for Vortech superchargers?
A: Most Vortech superchargers have a step-up ratio of either 3.47:1 or 3.60:1, but check your specific model's specifications.

Q2: What's the safe maximum impeller speed?
A: This varies by model, but generally 50,000-55,000 rpm is the safe maximum for most Vortech units.

Q3: How do I measure pulley diameters?
A: Measure the outer diameter where the belt rides. Aftermarket pulleys often have the size stamped on them.

Q4: Can I use this for other supercharger brands?
A: The calculation method is similar, but step-up ratios differ between brands. Use the correct ratio for your specific supercharger.

Q5: How does impeller speed affect boost?
A: Higher impeller speeds generally create more boost, but efficiency drops at very high speeds, creating more heat than boost.