Porsche 911 - Manual (Page 27)

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Porsche Doppelkupplung (PDK)
4 6 2 1
R 7
3 5
How Porsche Doppelkupplung
(PDK) works.
The crankshaft transmits engine
torque to the dual-mass flywheel
which is then channelled through
the clutch housing and onto the
multi-plate clutches, or to be more
precise, the outer disc carrier.
Under oil pressure, clutch 1
closes and forms a frictional
connection with input shaft 1.
The torque is now transmitted
through the differential to the
rear axle or, in the all-wheel drive
variants of the 911, the front and
rear axles.
At this stage, PDK has already
preselected the next gear. Engine
torque is already acting on the
other outer disc carrier and, in
response to a gear change signal,
the overlap shift is initiated,
i.e. as clutch 1 opens, clutch
2 closes. The non-positive
connection with input shaft 2
is established, and power is
transmitted to the wheels.
The gear which is engaged is
displayed on the instrument
cluster.
PDK has distinct benefits. The
very rapid gearshifts, with no
interruption in the flow of power,
produce faster acceleration.
4
6
2 R 1
3
7
5
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The new 911 | Transmission
Driving feels even sportier and
more dynamic, and agility is
increased. Depending on the
gearshift programme, the gear
change is optimised for comfort
or for sporty handling.
The compact dimensions of
the gearbox reduce rotational
masses which means a more
direct engine response, and the
system is more lightweight.
This, along with the long-ratioed
7 th gear, helps to achieve
reduced fuel consumption and
emission figures comparable
with those of a manual gearbox.
In conjunction with the new
engines, it has been possible to
reduce fuel consumption by
up to 14 % and CO
2
emissions
by up to 17 %, depending on
the model.
With the optional Sport Chrono
Package Plus, PDK is enhanced
by the ‘Launch Control’ and
‘motorsport-derived gearshift
strategy’ functions (p. 74).
In essence, PDK combines
sportiness with efficiency and
comfort.
What could be more appropriate
to a Porsche 911?
PDK function diagram
Multi-plate clutch 1
Multi-plate clutch 2
Semi-gearbox 2
(2nd, 4th, 6th gear)
Semi-gearbox 1
(1st, 3rd, 5th, 7th, R gear)
Differential
All-wheel drive
models
Engine
Front axle
Rear
wh
eel
Rear
wh
eel