PDK transmission question.

[Dottore]

Can someone explain to me how the PDK works in very simple terms?

[Matt Monson]

The simple answer is that it has two clutches. One is always engaged while the other is not. The gearbox ecu preshifts the next gear up or down before it is needed.
Then when it is needed it switches which clutch is engaged and you are in the next gear up or down. Repeat.

[robhamster]

The PDK in my Panamera works by pulling the lever of the PDK to the D position and hitting the gas still I feel like letting off!

[Tippy]

IIRC, gears 1, 3, and 5 are on one side of unit. 2, 4, 6 on the other. There is 2 clutches on the respective sides. So, when 1st gear is engaged with clutch engaged, the 2nd gear is engaged with clutch disengaged. Clutch releases on 1st gear side, then engages 2nd gear side while 3rd gear engaged with clutch disengaged and sequentially back and forth. Each side is connected to a central main shaft when each sides clutch is engaged.

[Walt Fricke]

It looks like it would be pretty tricky to retrofit a PDK into one of our pre-PDK cars.

At the least, some key electronics would be needed, as that does all the figuring out. And, for track use, somehow knows if you are going to be downshifting, or upshifting. Upshifts (taking miliseconds) are where these shine. If you have data, you can see that when you upshift with a conventional stick shift transmission, your speed actually drops a bit during the period when no power is applied to the drive wheels. And the higher the speed, the more pronounced this effect is, as aero drag increases exponentially with speed.

At a guess, maybe the costs would be sort of a wash as compared to selling the old car and buying a new one with a PDK already installed?

[HawgRyder]

I have been watching the Australian Super Car series lately...and they have a long shifter stick in the car which is bumped forward and backward to change gears.
Is this a PDK style of trans?
If not...it still shifts very quickly.
Bob

[Flieger]

That is just a sequential. Yes, they are very fast, but usually not as fast as PDK (but lighter).

By the way, dual-clutch transmissions are outlawed in F1, so they use standard single-clutch sequential gearboxes with electro-hydraulic actuation. When they want to shift, the computer engages the next gear before the next one is disengaged. They avoid a big kablammo by timing it so that the backlash in the gears allows the higher gear to pick up where the lower one left off just in the nick of time... usually.

[Matt Monson]

I have been watching the Australian Super Car series lately...and they have a long shifter stick in the car which is bumped forward and backward to change gears.

Is this a PDK style of trans?

If not...it still shifts very quickly.

Bob

Those run a Holinger sequential gearbox. It is a single clutch but because it uses dog gear engagement instead of synchros you can shift without using the clutch in race conditions.

[Flieger]

Like this:

[James Brown]

here is the engineering answer to the PDK, simple
Turbo Transmission Explained - YouTube

[Jandrews]

So is PDK a paddle-shifted "automatic" transmission like the Tiptronic, or is it a clutchless "manual" transmission more like the BMW SMG or Ferrari F1? I guess as technology advances these historical comparisons become less and less valid. These transmissions sort of blur the line between the traditional specs of what we knew as "automatic" vs "manual". I guess I still think of an automatic as something that utilizes a valve-body to shift and a torque converter to transfer power, and a manual as something that has a friction-based clutch disc and a flywheel.

Is this vernacular all in the history books with these new transmission technologies?

JA

[Bill Verburg]

It's essentially 2 manual transmissions in a single case, the input end is through 2 clutches and a hollow shaft, 1 clutch connects to one trans though the outer shaft the other clutch connects to the other trans through the inner shaft, the outputs of each trans is connected to the final output shaft through a gear set, the whole process is computer controlled and yes they could do this to a regular manual trans too