1. What is Stall Speed?

Stall speed is the maximum engine speed at which a torque converter can hold the vehicle stationary against the brakes. It's a critical parameter for performance vehicles and determines how quickly a car launches from a stop.

2. How Does the Calculator Work?

The calculator uses the stall speed formula:

Where:

• \( K \) — K-factor (rpm/√lb-ft), a characteristic of the torque converter
• \( Torque \) — Engine torque (lb-ft)

Explanation: The formula approximates stall speed based on the square root relationship between torque and the converter's stall characteristics.

3. Importance of Stall Speed Calculation

Details: Proper stall speed matching is crucial for optimizing vehicle launch performance, especially in racing applications. It affects how quickly the engine reaches its power band and how effectively power is transferred to the wheels.

4. Using the Calculator

Tips: Enter the K-factor specific to your torque converter (typically provided by the manufacturer) and your engine's torque output. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical K-factor value?
A: K-factor values typically range from 20-40 rpm/√lb-ft for street converters, with performance converters having higher values.

Q2: How accurate is this approximation?
A: This provides a good estimate, but actual stall speed can vary based on converter design, fluid characteristics, and other factors.

Q3: Should I use peak torque or torque at a specific RPM?
A: For best results, use the torque value at the RPM where you expect the converter to stall, which is often close to peak torque.

Q4: What affects stall speed in a torque converter?
A: Stall speed is influenced by converter design, stator angle, fin count, and the torque multiplication characteristics.

Q5: Can I change the stall speed of my torque converter?
A: Yes, but it requires physical modifications to the converter or replacing it with a different unit designed for your desired stall speed.