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Max Speed Calculator Gear Ratio

Max Speed Formula:

\[ MS = \frac{MaxRPM \times \pi \times TD}{GR \times AR \times 1056} \]

RPM
inches

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1. What is a Max Speed Calculator Gear Ratio?

Definition: This calculator estimates the maximum vehicle speed based on engine RPM, tire diameter, gear ratio, and axle ratio.

Purpose: It helps automotive enthusiasts and professionals determine theoretical top speed for gear ratio selection and performance tuning.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ MS = \frac{MaxRPM \times \pi \times TD}{GR \times AR \times 1056} \]

Where:

Explanation: The formula calculates how fast the tires rotate at maximum engine RPM, then converts this to miles per hour.

3. Importance of Max Speed Calculation

Details: Proper gear ratio selection ensures optimal vehicle performance, fuel efficiency, and prevents engine over-revving.

4. Using the Calculator

Tips: Enter your engine's maximum RPM, actual tire diameter (not wheel size), gear ratio, and axle ratio. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: This is theoretical max speed. Actual speed may vary due to aerodynamics, power limitations, and drivetrain losses.

Q2: Where do I find my gear and axle ratios?
A: Check vehicle specifications, transmission documentation, or differential tags. Gear ratio changes with each gear.

Q3: How do I measure tire diameter?
A: Measure from ground to top of tire under load, or calculate using tire size markings (e.g., 275/60R15).

Q4: Why does axle ratio matter?
A: The axle ratio provides final gear reduction after the transmission, affecting overall drive ratio.

Q5: What's a typical conversion factor?
A: 1056 combines conversions for inches to miles (63360), minutes to hours (60), and accounts for π.

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