How to Choose a Torque Converter

A torque converter is primarily used to increase the horsepower and torque available to accelerate a vehicle from a dead stop. It allows an automatic transmission to operate similar to a manual transmission. In a manual transmission, the engine rpm can be raised to increase the horsepower and torque prior to engaging the clutch. The stall converter allows stepping on the brake and raising the rpm prior to launching.

Instructions

1. Determine the exact weight of the vehicle, including passenger and fuel. Determine the exact size of the camshaft and at what operating range it is designed for. The camshaft information can be found on the camshaft card that came with the cam.

2. Determine the brake horsepower of the vehicle using a dynometer. Determine the tire size in terms of contact patch by measuring the footprint of the tire. Determine the usage and rpm range desired. If towing is the major concern, a low rpm stall to give more torque for initial pulling from a stop is all that is needed. The higher the stall is, the higher the rpm will be when cruising.

3. Determine the gear ratio in the rear. Call the manufacturer or the speed shop with this information. They can look up the proper stall converter that gives the optimum performance for the intended purpose.

References

• Don Bowman, A.S.E. Certified Mechanic

Resources

• B & M Torque Converters
• TCI Torque Converters