1. What is Stall Speed?

Stall speed is the maximum speed at which a torque converter can multiply torque while the input is rotating but the output is stationary. It's a critical parameter in automotive performance applications.

2. How Does the Calculator Work?

The calculator uses the stall speed approximation formula:

Where:

• \( K \) — K-factor (rpm/√lb-ft), typically ranges from 15-25 for most torque converters
• \( \text{torque} \) — Engine torque in lb-ft

Explanation: This formula provides an approximation of stall speed based on the torque multiplication characteristics of the torque converter.

3. Importance of Stall Speed Calculation

Details: Proper stall speed selection is crucial for optimizing vehicle launch characteristics, acceleration, and overall performance. Matching stall speed to engine torque characteristics ensures efficient power transfer from standstill.

4. Using the Calculator

Tips: Enter the K-factor value (typically provided by the torque converter 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 range?
A: Most performance torque converters have K-factors between 15-25 rpm/√lb-ft, with higher values indicating more aggressive torque multiplication.

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

Q3: When should I use a higher stall speed?
A: Higher stall speeds are beneficial for engines that produce peak torque at higher RPMs, such as modified or high-performance engines.

Q4: What happens if stall speed is too high?
A: Excessive stall speed can cause poor street manners, increased heat generation, and reduced fuel efficiency in daily driving situations.

Q5: Can I use this for any torque converter?
A: This formula works best for performance torque converters. Stock converters may have different characteristics that don't follow this approximation as closely.