DCT’s: the differences between the dry and wet clutch

Posted on 09-04-2015 at 21:28 by MauritsH – 68 Comments”

No, the one is not in a permanent state of excitement, and the other is not blessed with an excellent sense of humor, but what are, however, the differences between DCT with wet and dry clutch?

For those who are equally lost: Dual Clutch Transmissions (DCT’s) are transmissions in which use is made of two links. Despite the interesting technique to prove such baking, in practice, somewhat fragile and quite subject to wear and tear. And then not a little but a little quantity. Anyway, the exact effect of this type of transmission, you can read back HERE once again.

DCT’s are under different names built. Volkswagen uses DSG, Porsche is doing with PDK and Lamborghini calls their system LDF. The list goes much further, we’ll keep it for now, next to the DSG of VW.

Volkswagen offers two types of DSG’s. The one is equipped with a dry clutch, the other of a wet. The dry variant is in turn provided with a single clutch plate, which in the vacuum is running. The wet clutch consists of multiple plates that their thing to do in an oil bath.

That last is especially useful for motors with a higher torque. VW makes three different DSG’s. The DQ200 dry-clutch and seven oppose it can hold up to 250 Nm. The two variants with wet clutches (DQ250 and DQ500) can be respectively 350 Nm and 550 Nm. Why? Just because they are ‘wet’.

The continuous running of the coupling in an oil bath is good for cooling and that is exactly what wet variants are more suitable for engines with strong torque. Incidentally, were the first DCT’s anyway, dressed with wet clutches, dry did later on his appearance.

Of course, it is not only hosanna in regards to the wet DSG. Because the link continuously through an oil bath is running and because the oil must be pumped, there is some power lost through the extra resistance. The CO2-emissions is therefore also somewhat higher.

Big advantage is of course that such a DSG thanks to the oliekoeling stronger engines. For your information: even the Veyron with z’n 1.250 Nm had one.