A dual clutch transmission (also known as a DCT) uses two clutches to make extremely quick and seemless shifts. These clutches can either be dry clutches (like the clutch found in most cars with manual transmissions), or wet clutches (like those found in many motorcycles and ATVs). Each one of the clutches has its own set of gears, meaning that the dual clutch transmission contains most of the parts to make up two separate transmissions.
One clutch works with the odd number gears, while the other works with the even number gears. When you are in first gear, the second clutch and ‘transmission’ has already preselected second gear. When the computer commands a gear change or you pull the gear lever the second clutch engages while at the same time the first clutch disengages. The result is a seemless transfer between the two gears, and a nearly uninterrupted transfer of power. This means smoother shifting, no loss of boost in turbocharged vehicles, and quicker acceleration.
While dual clutch transmissions have only recently become available in road vehicles, they have been in use for quite some time. In 1985 they were used in the Porsche 962 Group C and IMSA race cars, and they also made a few appearances in the awesomely powerful Audi Sport quattro S1 Evolution 2 Group B rally cars.