1. What is Torque Converter Stall Speed?

Stall speed is the maximum engine speed at which the torque converter can hold the vehicle stationary with the brakes applied and the transmission in gear. It's a critical parameter for performance tuning and transmission design.

2. How Does the Calculator Work?

The calculator uses the stall speed equation:

Where:

• \( Torque \) — Engine torque in pound-feet (lb-ft)
• \( K \) — Torque converter constant (typically between 0.0001 and 0.0003 for street vehicles)

Explanation: The stall speed increases with higher torque and decreases with higher K values (which represent converter tightness).

3. Importance of Stall Speed Calculation

Details: Proper stall speed selection improves launch performance, matches engine power band, and prevents excessive slippage in normal driving.

4. Using the Calculator

Tips: Enter torque in lb-ft and the converter's K factor. Typical K values range from 0.00015 (loose) to 0.00025 (tight) for street applications.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical stall speed for street cars?
A: Most stock converters stall between 1800-2500 RPM. Performance converters may be 2800-3500 RPM.

Q2: How does stall speed affect performance?
A: Higher stall allows the engine to reach its power band quicker, improving acceleration but reducing efficiency.

Q3: What happens if stall speed is too high?
A: Excessive slippage, heat buildup, poor fuel economy, and difficulty with street driving manners.

Q4: How do I determine my converter's K factor?
A: Manufacturers provide this value, or you can calculate it if you know stall speed and torque (K = Torque/Stall²).

Q5: Does stall speed affect transmission life?
A: Yes, excessively high stall speeds can increase heat and wear on transmission components.