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Old 12-21-2007, 02:27 PM   #5 (permalink)
cfg83
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MetroMPG -

I never heard of "dual-clutch manual transmissions" before :

How Dual-clutch Transmissions Work
http://auto.howstuffworks.com/dual-c...ansmission.htm
Quote:
Hands-On or Hands-Off
A dual-clutch transmission offers the function of two manual gearboxes in one. To understand what this means, it's helpful to review how a conventional manual gearbox works. When a driver wants to change from one gear to another in a standard stick-shift car, he first presses down the clutch pedal. This operates a single clutch, which disconnects the engine from the gearbox and interrupts power flow to the transmission. Then the driver uses the stick shift to select a new gear, a process that involves moving a toothed collar from one gear wheel to another gear wheel of a different size. Devices called synchronizers match the gears before they are engaged to prevent grinding. Once the new gear is engaged, the driver releases the clutch pedal, which re-connects the engine to the gearbox and transmits power to the wheels.

So, in a conventional manual transmission, there is not a continuous flow of power from the engine to the wheels. Instead, power delivery changes from on to off to on during gearshift, causing a phenomenon known as "shift shock" or "torque interrupt." For an unskilled driver, this can result in passengers being thrown forward and back again as gears are changed.

[diagram of dual-clutch transmission, 6-speed basic design]

A dual-clutch gearbox, by contrast, uses two clutches, but has no clutch pedal. Sophisticated electronics and hydraulics control the clutches, just as they do in a standard automatic transmission. In a DCT, however, the clutches operate independently. One clutch controls the odd gears (first, third, fifth and reverse), while the other controls the even gears (second, fourth and sixth). Using this arrangement, gears can be changed without interrupting the power flow from the engine to the transmission. Sequentially, it works like this: ...
EDIT: Hrmmmm, on second thought, I don't like this. I won't be able to coast in neutral anymore, .

CarloSW2
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Last edited by cfg83; 12-21-2007 at 02:31 PM..
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