As on conventional manual gearboxes, the transmission ratios are present on input and auxiliary shafts in the form of pairs of toothed wheels. In contrast to manual gearboxes, the input shaft is divided into two sections. It comprises an outer hollow shaft, and an inner shaft. The 1st, 3rd, 5th gears and reverse are located on the inner shaft. The hollow shaft handles the even-numbered gears.
Each of these shafts is selected by means of a separate multi-plate clutch running in oil. The two electronically controlled, hydraulically actuated clutches are packed inside each other for maximum space economy.
As well as their high efficiency and ability to transmit high torques, clutches of this type permit a wide range of starting characteristics. In other words, the multi-plate clutch can be controlled in such a way that every conceivable form of pulling away is possible, from an ultra-gentle edging along on a slippery surface to sports-style acceleration at full throttle.
The gearshifts it produces feel spontaneous and decisive, as if executed at the push of a button. The electronic-control throttle blip feature of the manual and S modes reinforces the impression of ultra-dynamic gearshifts.
A shift-by-wire control concept has been implemented. The mechatronic concept combines a control unit with an electro-hydraulic control unit. The resulting device is housed in the upper section of the transmission casing. The signals from ten individual sensors are processed centrally there, and the actuation values calculated using the relevant information on the momentary driving situation from the drive CAN bus. The application pressure of the two clutches is regulated by special solenoid-operated valves depending on the situation, and the gear positioners operated.
The electronics also calculate which additional gear is to be preselected by the corresponding positioning cylinder and selector forks, and manages all actuating elements and the oil cooling circuit via six pressure regulation valves and five on/off valves.
All in all, the entirely new concept results in a decidedly agile performance, with the added benefit of the typically low fuel consumption of an advanced 6-speed manual gearbox.
Audi TT 3.2: Dynamic Through And Through
A 17-inch dual-piston brake system adapted from the version used on the RS 4 assures an appropriate braking performance. There are floating-caliper brakes with ventilated 334 millimetre brake discs at the front. The rear wheels are fitted with floating-caliper brakes with 265 millimetre ventilated brake discs. In common with all TT models, the new 3.2 quattro has ESP with integral brake assist.
The dynamism of the new top-of-the-range TT version is moreover outwardly in evidence. The main changes compared with the other TT models are the modified rear spoiler and the rear apron with enlarged inlet openings and lateral gills. The larger rear spoiler further reduces rear-end lift, in line with the performance gain of the TT 3.2 quattro.
The front apron now incorporates larger openings to cover the higher demand for cooling air, without the aerodynamic properties being affected. The drag coefficient remains unchanged at Cd = 0.32.
The TT 3.2 quattro in addition has xenon lights as standard with range control and titanium-coloured headlight trims. Inside, as well as the shift paddles on the steering wheel this version is distinguished by a gearbox gate in polished aluminium.
The market launch is scheduled for mid-2003.Published 23 November 2002