Torque Converter Stall Speed Calculator

Stall Speed Formula:

\[ Stall\_speed = \frac{\tau_{max} \times 5252}{HP} \]

Stall Speed (rpm):

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1. What is Torque Converter Stall Speed?

Torque converter stall speed is the maximum engine speed at which the torque converter can multiply torque when the output shaft is held stationary. It represents the RPM at which the converter transfers maximum torque to the transmission.

2. How Does the Calculator Work?

The calculator uses the stall speed formula:

\[ Stall\_speed = \frac{\tau_{max} \times 5252}{HP} \]

Where:

\( \tau_{max} \) — Maximum torque (lb-ft)
\( HP \) — Horsepower (hp)
5252 — Conversion constant (since 1 hp = 550 ft-lb/s and there are 2π radians per revolution)

Explanation: The formula calculates the RPM at which the torque converter reaches its maximum efficiency point based on the engine's torque and horsepower characteristics.

3. Importance of Stall Speed Calculation

Details: Proper stall speed selection is crucial for optimal vehicle performance. A correctly matched torque converter improves acceleration, towing capability, and overall drivability by matching the converter's characteristics to the engine's power band.

4. Using the Calculator

Tips: Enter maximum torque in lb-ft and horsepower in hp. Both values must be positive numbers. The calculator will compute the theoretical stall speed in RPM.

5. Frequently Asked Questions (FAQ)

Q1: Why is 5252 used in the formula?
A: 5252 is a conversion constant derived from the relationship between horsepower and torque (1 hp = 550 ft-lb/s and there are 2π radians per revolution).

Q2: What is a typical stall speed range?
A: Stall speeds typically range from 1500-3500 RPM for street applications, while performance converters can have stall speeds of 4000+ RPM.

Q3: How does stall speed affect vehicle performance?
A: Higher stall speeds allow the engine to reach its power band quicker, improving acceleration. Lower stall speeds provide better fuel economy and drivability.

Q4: Can I use this calculator for any vehicle?
A: This calculator provides a theoretical value. Actual stall speed may vary based on converter design, fluid characteristics, and other factors.

Q5: What if my calculated stall speed seems too high or too low?
A: Double-check your torque and horsepower values. Remember that this is a theoretical calculation - actual converter performance may differ.