What is a DSG Powershift Transmission
If you can’t tolerate complex technical explanations, all you need to know is if a car is fitted with DSG it means it’s automatic. Just like a traditional auto, you can slot it in ‘D’ and pootle about at your own leisure and it’ll shift gears for you – and like an auto you can come to a stop and pull away without fear of stalling or having to use a clutch.
You can also select ’S’ mode (it stands for sport) – which makes the car holds onto gears longer for better acceleration – or ‘M’ for manual, allowing the driver to control the gear selection using the lever or using (flappy) paddles mounted behind the steering wheel.
You still don’t need to worry about over-revving the engine by shifting down at high revs – the DSG unit is packed with electronics to look after itself.
Wet Clutch Systems
In wet-clutch designs, the oil acts as a medium for heat transfer, minimising the overall operating temperature of the clutch assembly. By reducing operating temperatures, the formation of varnish and lacquer on the clutch plates is also minimised.
The formation of lacquer and varnish caused the frictional characteristics of the plates to change, promoting slippage and increased heat, and promoting rapid deposit formation and the risk for plate distortion.
The fluid used in wet-clutch configurations helps to reduce the build-up of wear debris on the frictional plates, and provides lubrication to components and wear areas within the clutch, such as the bearings and points of contact between the clutch baskets and the outer tabs of the frictional plates.
There are three different configurations for wet-clutches:
Where there is an isolated fluid reservoir for the clutch that is separated from the transmission and engine – the oil provides lubrication for the clutch, as well as a roller chain or single gear set.
A shared transmission and clutch fluid reservoir – the oil provides lubrication for both the clutch and transmission.
A common engine, clutch, and transmission reservoir – this is the most prevalent configuration found in most motorcycles, and requires a multi-faceted fluid that can lubricate all three.
Good wet-clutch performance is essential for satisfactory drivability. Cleanliness, frictional properties, oil compatibility, shear stability, anti-foaming properties, and high-temperature stability are all critical in maintaining the performance and integrity of a wet-clutch system.