Understanding Torque Converters

A torque converter is the counterpart of the clutch in an automatic transmission. It engages or disengages the engine to the transmission so that a car runs and stops when you need it to. In simple terms, a torque converter is a fluid coupling that has made up of two fan-looking parts. One fan known as impeller is attached to the engine. This is one end of the torque converter. The other end has another fan referred to as turbine that connects to the transmission.

The torque converted functions through the transmission fluid. The turbine spins as the impeller presses oil onto it. If you hit the car’s brakes, the turbine stops while impeller continues on spinning.

Located in between the impeller and turbine blades is the stator. The job of the stator is mainly to push the oil back to the impeller. Slippage is a result of the stator’s ability to spin faster than the turbine. To control the slip factor, a stall speed must be established. It means getting the point where the engine’s power will either start moving the car or the power doesn’t go above that point anymore no matter how you step on the accelerator.

Race drivers prefer torque converters with high stall speed to give them a high power boost at the starting line. In buying a race torque converter, it is important to base your choice on the stall speed rather than the physical size of the converter. Large torque converters normally have lower stall speed and weigh heavier than smaller ones.

A racing torque converter may look just like the regular converter, only smaller in diameter. They are also more efficient than stock converters owing to the kind of materials used.

However, stall speed is not solely determined by engine power. Factors such as modifications made to the car and its other components may also affect stall speed. It is therefore advisable to give your converter dealer or manufacturer all information in regard to where and how the torque converter will be used.

One drawback of high stall speed converters is that its efficiency normally decreases as stall speeds go higher. Also, smaller torque converters are more prone to slippage than the larger stock converters.

This is why there is really no simple equation in choosing the torque converter that will be able to serve your need, unless you consult with the professionals. They should be able to properly assess your overall car set-up- body, chassis, mechanical, and electrical, and then recommend the suitable torque converter for your specific application.