1. What Is Stall Speed?

Stall speed is the maximum engine speed at which a torque converter can hold back the engine under full throttle without allowing the vehicle to move forward. It's a critical parameter in automotive performance tuning.

2. How Does The Calculator Work?

The calculator uses the stall speed formula:

Where:

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

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

3. Importance Of Stall Speed Calculation

Details: Proper stall speed selection is crucial for optimizing vehicle launch characteristics, improving acceleration, and matching the torque converter to the engine's power band.

4. Using The Calculator

Tips: Enter the K-factor (typically provided by the 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 street performance converters have K-factors between 15-20, while racing converters may have values up to 25 or higher.

Q2: How does stall speed affect driving?
A: Higher stall speeds allow the engine to reach its power band faster but may reduce low-speed drivability and fuel economy.

Q3: When should I consider a higher stall converter?
A: Higher stall converters are beneficial for vehicles with modified engines that make power at higher RPMs, or for improved launching in drag racing applications.

Q4: Are there limitations to this calculation?
A: This is an approximation - actual stall speed can vary based on converter design, fluid temperature, and other factors.

Q5: Can I use this for any vehicle?
A: This calculation works for most rear-wheel drive vehicles with automatic transmissions. Front-wheel drive applications may require different considerations.