Transmision DSG Volkswagen

Hot on the heels of Audi's announcement of the Audi TT 3.2 with DSG, Volkswagen announces its first application of their new six-speed Direct Shift Gearbox (DSG) in the Golf R32.

The all-new DSG transmission is a race bred system that has now been developed for street applications. Used back in the 1980's in Audi's Sport Quattro S1 racers, this transmission utilizes two multi-plate clutches that can simultaneously have two gears selected, one engaged the other waiting. When a gear shift is made via paddles located behind the steering wheel, both clutches are opened, gears change and clutches close in a fraction of second under full load with virtually seamless power maintained. In a down shift situation DSG will even blip the throttle to match revs. DSG can also be utilized just like a regular automatic transmission with both a conservative "D" position and an aggressive "S" sport position.

People that have driven this setup tell us that it is still a fairly aggressive system and is not necessarily designed to replace standard Tiptronic or CVT transmissions since those tend to be a bit smoother in shift transitions. Our best guess is that we could see this system utilized in GTI or GLI models or in future "R" or sport variants where this transmission would shine in performance applications as a second transmission option to a manual stick shift.

The full Volkswagen AG press release follows below:

Wolfsburg, Germany - Volkswagen presents a world-wide technical innovation: the sporty and economical automatic gearbox "DSG". This gearbox with integrated dual clutch will be used for the first time in the Golf R32. In the course of the year 2003, its use will be extended to other production series - primarily in conjunction with high-torque engines. With the new dual-clutch gearbox, Volkswagen continues its powertrain offensive across all classes.

Volkswagen was one of the first manufacturers to offer manual 6-speed gearboxes as optional equipment in the volume segment for certain production series and models. In the luxury class, a new 6-speed automatic for the Touareg V10 TDI will be introduced in mid-September. Early in October, with the New Beetle Cabriolet, Volkswagen became the first manufacturer to offer a transversally installed 6-speed automatic gearbox in the compact class - a configuration long considered impossible. With the DSG, the company now extends this spectrum by a technically completely new type of gearbox.

The DSG will be manufactured at the Volkswagen plant in Kassel, where 150 million Euro were invested in production. At full capacity, up to 1,000 DSG can be produced per day.

The gearbox has been designed to fulfil the demands of European customers for sporty driving and fuel economy. One significant difference to the familiar automatic gearboxes which are established especially in the USA in all classes: The DSG does not employ a torque converter for a standing start. Nor is the DSG a derivative of the automated manual transmission used in the Lupo 3L TDI. Rather, the DSG engineers took a technically completely new and revolutionary path by harmonizing the agility of a manual transmission with the ease of a conventional automatic gearbox.

The DSG is significantly superior to the manual gearbox regarding fuel economy and performance, speed and ease of shifting as well as driving fun.

This new Volkswagen gearbox offers a genuine alternative in particular to those drivers who up to now have preferred manual gearboxes, because the DSG suffers no disadvantage in terms of fuel economy or performance. On the contrary: with identical acceleration and top speed, it shifts as smoothly as the best conventionally built automatic gearboxes; in addition, manual shifting is possible using the Tiptronic function or, in the Golf R32, buttons in the steering wheel. And shifting occurs faster and more "crisply" than possible up to now with either manual or automatic gearboxes, and without interrupting tractive power.



Volkswagen DSG - Gearshifts take only a few hundredths of a second

- In the DSG, the next gear is permanently engaged and ready for activation

- DSG matches revs in the finest sporting fashion during downshifts

As one of its outstanding design characteristics, the transversally installed DSG gearbox possesses two wet clutches (greater thermal capacity and better regulation than dry clutches), the pressure of which is hydraulically regulated. The so-called clutch 1 (C1) serves the odd gears (plus reverse) and clutch 2 (C2), the even ones. Therefore, for all intents and purposes, one must speak of two parallel gearboxes in one. A consequence of this elaborate clutch management: during a shift, there is no more interruption of tractive power, typical of an automated manual transmission. Consequently an incomparably dynamic and, at the same time, smooth shift feeling with a high degree of comfort is conveyed The high efficiency of this gearbox is very close to that of the classic manual gearbox.

Together with Mechatronic, an intelligent hydraulic and electronic gearbox control, the two wet clutches with two input and output shafts are responsible. This interconnection enables the next higher gear permanently to be engaged and ready for activation. And like lightning, to be sure. For example: While the car is being driving in third gear, fourth gear is already engaged, but is not yet active. As soon as the ideal shift point is reached, the clutch for third gear opens while the other closes, activating fourth gear. The opening and closing of the clutches coincide in the process, producing the smooth shift already mentioned above. The entire shift process is completed in the especially short time of 3 to 4 hundredths of a second.

Parallel to the fully automatic shift programs "D" and "S", the DSG has a Tiptronic function which enables manual shifting. Beyond that, the driver of a Golf R32 can select gears using shift buttons in the steering wheel. In both cases, the result is a shift feeling marked not only by superior comfort but also by extreme fun when shifting. Drivers with sporty ambitions will experience for the first time that gears can be changed as with the press of a button. And what's more: In the even sportier mode (position "S"), the engine and gearbox control units even activate a form of rev-matching, which further enhances the shift dynamics: Using wheel speeds provided by the ABS, the gearbox control unit ensures that no unintended up-shift occurs in the middle of a curve.

It is generally true that an engine coupled to the DSG is always in the position spontaneously to have the desired tractive power available due to the fast, independent gear change. No less decisive is the fact that the new gearbox provides the great agility of a manual transmission but undercuts the latter substantially in fuel economy. The R32 with DSG consumes only 10.2 liters Super Plus petrol per 100 km, undercutting the manual version by about one and a half liters (11.5). Such extreme fuel reduction can otherwise be achieved only through the use of extremely lightweight building materials. Acceleration is tangibly better than for a manual. Equipped with DSG and an integrated launch control (an electronic start program), the Golf R23 sprints to 100 km/h (about 61 mph) in only 6.4 seconds (with manual gearbox in 6 seconds). The top speed of 247 km/h (about 151 mph) is the same.

With the DSG, Volkswagen is the first manufacturer to develop a dual-clutch gearbox ready for production. Such gearboxes have already been used in motor sports, but the uncomfortable shifting due to inadequate means of mechanical and electronic control made them unacceptable for use in production cars. In its own undertaking, Volkswagen solved the problem of exacting demands in design; in addition to numerous new hydraulic components, a complex Mechatronic was developed which first made possible the DSG as it is now being introduced in the Golf R32.

The new automated 6-speed gearbox was designed for a maximum torque capacity of 350 Newton meters (268 lb-ft of torque). Including 6.4 liters of oil, it weighs 90 kilograms (198 lbs). Viewed from the engine side, the aluminum clutch housing with splines and pilot journal pin of the gearbox input shaft, the gear teeth of the differential and, in the upper section, the parking lock actuator can be seen.

From the side away from the engine, one sees the entire gearbox housing with a heat exchanger for optimizing the thermal balance, a pressure filter for cleaning oil, the outer cover for the Mechantronic integrated in the gearbox and the oil pump as well as a socket serving as interface to the vehicle electronics.