PDK: ZF press release

rocket · #1 (**permalink**) 07-21-2008, 03:01 AM

I just thought you'd might find this interesting (read the caption in red):

Quote:

ZF Friedrichshafen AG – Press Information

(19/06/2008)

7-Speed Dual Clutch Transmission by Porsche and ZF Enters Volume Production

* Faster gearshifts without traction interruption.
* Lower consumption with improved driving performance.
* Presentation at the 'Transmissions in Vehicles' Event of the VDI (Association of German Engineers) in Friedrichshafen.
* Volume production launch in the Porsche 911 Carrera.

The new dual clutch transmission is presented for the first time to approximately 900 engineers and press representatives at the VDI 'Transmissions in Vehicles' Event in Friedrichshafen. The 7DT sports transmission is particularly suited for applications with high engine speed requirements. Gear changes without traction interruption allow for very good acceleration and vehicle handling with low fuel consumption. The transmission was developed in Kressbronn, Brandenburg, and Schweinfurt; it is produced at the Brandenburg site of ZF's Car Driveline Technology division.

Drivers of sporty cars expect their vehicle's engine power to be transformed as directly as possible into dynamic propulsion. In addition to this acceleration "linked directly to the accelerator", however, they also attach great importance to automatic shifting comfort. ZF's 7-speed sports transmission accommodates both requirements for vehicles featuring highly powerful engines: the sporty agility of a manual transmission and the shifting comfort of an automatic transmission.

In the dual clutch transmission this becomes possible by connecting two separate transmissions to the engine via two parallel powershift clutches. The even gears are located on one transmission, the uneven ones on the other. This basic principle of the transmission has the advantage that one gear in one of these transmissions ensures propulsion, whereas in the other transmission the next gear is already preselected by the electrohydraulic control unit. When shifting, one clutch is closed while the other opens. During the shifting process, traction is not interrupted. This means that, during acceleration, engine torque is continuously transformed and propels the vehicle – making an essential difference from the manual transmissions which were usually installed in powerful sports cars. In contrast to torque converters, the dual-clutch module by ZF Sachs, the Powertrain and Suspension Components division of ZF, is also suited for higher speeds of up to 8,000 revolutions.

All gear changes – also downshifts – are processed just as evenly and quickly with the 7DT 50 (that is the ZF-internal product designation); so the ZF dual clutch transmission sets a new benchmark for sportiness. A new speed governing concept, which is used for the first time in volume production with the 7DT, also contributes to these extremely short shifting times.

The drivers can choose from fully automatic shifting or manual gear selection via shift paddles or a shift lever. Also in the fully automatic mode, ZF offers several shifting programs: Apart from the comfort mode, there is also a sports and a supersports mode, the latter with considerably increased shifting dynamics (fastest shifting times and race-start function).

The 7DT sports transmission by Porsche and ZF excels thanks to its high power-to-weight ratio: The gears and shafts of the dual clutch transmission, which weighs approximately 120 kg, are produced from case hardened steel according to special, ZF-specific delivery instructions. ZF-engineers have introduced several measures - for example, controlling the cooling fluid flow as required to keep drag losses low. The 7-speed dual clutch transmission not only allows for particularly sporty driving performance but, thanks to its very good efficiency, also achieves consumption values which are below those of a manual transmission.

Especially with sports cars, there is a demand for transaxle transmissions – that is, transmissions with an integrated differential and axle drive – the 7DT sports transmission can also be supplied in this variant, which is suited for mid-engined vehicles with rear axle or all-wheel drive. This transaxle version of ZF's 7-speed dual clutch transmission is starting volume production in the torque range up to 450 Newton meters.

Caption:

New reference with dual clutch transmissions: The 7DT sports transmission by Porsche and ZF is available in two versions, for torques up to 450 and up to 700 Newton meters.

Photos: ZF

ZF is a leading worldwide automotive supplier for Driveline and Chassis Technology with approximately 60 000 employees at 119 locations in 25 countries. In 2007, the ZF Group achieved sales of EUR 12.6 billion. In order to continue to be successful with innovative products, ZF annually invests approximately five percent of its sales (2007: EUR 694 million) in Research and Development.

http://www.zf.com/content/media/konz...56_7dt45_e.doc

**blueone** · #2 (**permalink**) 07-21-2008, 03:55 AM

The PDK weighs 120kg? That's very heavy, or does it include the differential too? Hmmm... even if it does, that's seems heavy.

**Nitro8472** · #3 (**permalink**) 07-21-2008, 06:43 AM

Hmmm, so that means its ready for the TT already!!

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