History
This type of transmission was invented by Frenchman Adolphe Kégresse just before World War II but he never developed a working model. The first development of the Twin Clutch or Dual-clutch transmission started in the early part of 1980 under the guidance of Harry Webster at Automotive Products (AP), Leamington Spa with prototypes built into the Ford Fiesta Mk1, Ford Ranger & Peugeot 205. Initially, the control systems were based on purely analogue/discrete digital circuitry with patents filed in July 1981 . All of these early AP Twin Clutch installations featured a single dry clutch & multi-plate wet clutch. Following discussions between VW/Porsche, DCT work continued from Porsche in-house development, for Audi and Porsche racing cars later in the 1980s, when computers to control the transmission became compact enough: the Porsche Doppelkupplungsgetriebe (English: dual-clutch gearbox) (PDK) used in the Porsche 956 and 962 Le Mans race cars from 1983, and the Audi Sport Quattro S1 rally car.
A dual-clutch transmission eliminates the torque converter as used in conventional epicyclic-geared automatic transmissions. Instead, dual-clutch transmissions that are currently on the market primarily use two oil-bathed wet multi-plate clutches, similar to the clutches used in most motorcycles, though dry clutch versions are also available.
The first series production road car to be fitted with a DCT was the 2003 Volkswagen Golf Mk4 R32.
As of 2009, the largest number of sales of DCTs in Western Europe are by various marques of the German Volkswagen Group, though this is anticipated to lessen as other transmission makers and vehicle manufacturers make DCTs available in series production automobiles. In 2010, on BMW Canada's website for the 3 Series Coupe, it is described both as a 7-speed double-clutch transmission and as a 7-speed automatic transmission. It is actually a dual-clutch semi-automatic.
Read more about this topic: Dual-clutch Transmission
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