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Performance Torque Converter Install

Getting more performance from the same horsepower

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.

Torque Multiplier

If your car has an automatic transmission, it has an additional torque "multiplier" above and beyond the trans and differential gears. This unit is called the torque converter—a fluid coupling that disengages the engine from the transmission at idle so that you can pull to a stop or shift gears without stalling the engine. The torque converter is actually a misnomer—it should be called the "torque multiplier" because it doesn't simply provide a one-to-one connection to the transmission like a clutch does with a manual transmission.

Custom Converters

That's where custom torque converter manufacturers like Pro Torque come in. They analyze your vehicle—items such as horsepower, torque, weight, transmission type, gear ratio and tire size—and then design a custom torque converter specifically for your vehicle. Pro Torque custom machines the internal components to provide the correct stall speed (slip), and the company also modifies the unit for increased durability by furnace-brazing the impeller and turbine vanes in place in addition to installing a larger ceramic-impregnated lock-up clutch.

Real-World Test

We found a perfect vehicle to do a Pro Torque custom torque converter installation. Tommy Pierson, President of K&P Engineering in Irwindale, California (one of the nation's oldest Go-Kart manufacturers), was tweaking and testing a 2000 supercharged Ford Lightning F-150 pickup truck. He'd installed the usual bolt-ons, including an 80mm thottle body, a Swanson Performance engine management chip and a set of 26x11.50-16 Mickey Thompson slicks. The sum of these changes had reduced his 1/4-mile times from the low 14s to 13. 33 @ 102.5 mph. However, the Lightning still felt lazy off the starting line. Pro Torque had just the solution: a 10.5-inch diameter 2,400 rpm stall-speed lockup torque converter.

Resource

For more information contact Pro Torque, 1440 Church St., Bohemia, New York, NY 11716, (631) 281-8700, FAX (631) 218-9782, www.protorque.com.