Performance Torque Converter Install

What many car enthusiasts don't know, or simply overlook, is that you can get more performance out of the power you already have.
Many car enthusiasts believe that the path to better performance is through engine modifications. The problem is that engine modifications often don't work out exactly as you hope. Modifying a daily driver's engine can be tricky business, sacrificing one benefit in favor of another: low-end torque for top-end horsepower, fuel economy for acceleration, or even worse, reliability for that newfound performance.


What many car enthusiasts don't know, or simply overlook, is that you can get more performance out of the power you already have. Power (more accurately, torque) is never delivered directly from the flywheel to the pavement, without first being multiplied by gear ratios in the transmission and differential. The math is pretty simple: A car with a 4.0:1 gear ratio puts 33% more torque to the wheels than a car with a 3.0:1 gear ratio with no increase in engine torque.


However, changing gear ratios is another one of those compromises. Driveablity is adversely affected because the engine revs higher at all speeds, uses more fuel and simply wears itself out faster. Bottom line: Gears will help your car accelerate quicker—you'll just hate the added rpm if you drive your vehicle any distance.

Today's new cars have some very efficient torque converters, but they lack the necessary stall speeds for optimal performance.
Torque multiplication is just one important parameter for selecting a torque converter. Stall speed—the speed at which the converter slips under full throttle, full-load operation—is important as well. Early race/street type converters focused solely on stall speed. As long as the converter slipped enough to get the engine into the torque peak, it was considered a success. Not very efficient, but it worked. Today's new cars have some very efficient torque converters, but they lack the necessary stall speeds for optimal performance.

Typically, Pro Torque builds torque converters with stall speeds of 2,400-2,800 rpm versus OE factory stall speeds of 1,300-1,700 rpm.
What's the down side of installing a high-performance torque converter? With today's lock-up overdrive transmissions, the answer is not much. Typically, Pro Torque builds torque converters with stall speeds of 2,400-2,800 rpm versus OE factory stall speeds of 1,300-1,700 rpm. In normal driving conditions, you won't notice much difference; under heavier-throttle scenarios, you may notice that the engine revs a little quicker. But as soon as the vehicle hits the higher gears, the torque converter locks up and the engine and transmission become solidly coupled.