· 42 ·· 43 ·
The optional Porsche Doppel-
kupplung (PDK), with both man -
ual gearshift and an automatic
mode, enables smooth gear
changes with no interruption in
the flow of power. This results
in significantly faster acceleration
and lower fuel consumption, without having to sacrifice the
ease of automatic transmission.
In total, PDK has seven gears at
its disposal. Gears 1 to 6 have a
sports ratio and top speed is
reached in 6th gear. The 7th gear
has a long ratio and helps to
For people who have no time to spare.
Even when changing gear.
Porsche Doppelkupplung (PDK).
reduce fuel consumption even
f u rt h e r.
PDK is essentially t wo half gear-
boxes in one and thus requires
t wo clutches – designed as a
double wet clutch transmission.
This double clutch provides an
alternating, non-positive connec -
tion bet ween the t wo half gear -
boxes and the engine by means
of t wo separate input shafts
(input shaft 1 is nested inside the
hollowed-out input shaft 2).
The flow of power from the
engine is only ever transmit ted
through one half gearbox and
one clutch at a time, while the
next gear is preselected in the second half gearbox. During a
gear change, therefore, a con
-
ventional shif t no longer takes
place. Instead, one clutch simply
opens and the other closes at
the same time. Gear changes
can therefore take place within
milliseconds.
Clutch 1 controls the first half
gearbox, which contains the odd
gears (1, 3, 5, 7) and reverse.
Clutch 2 controls the second,
Boxster | Drive
which contains the even gears
(2, 4, 6).
Porsche Doppelkupplung (PDK)
in detail.
The crankshaf t transmits engine
torque to the dual-mass fly wheel
which is then channelled through
the clutch housing and onto the
multi-plate clutches, or to be more
precise, the outer disc carrier.
4
6
2
1
R
7 3
5
Porsche Doppelkupplung (PDK)
Boxster S
· 54 ·· 55 ·
Boxster | Chassis
Compression in ‘Normal’ mode –
working piston and bypass, sporty-
comfortable tuning Rebound in ‘Spor t ’ mode –
working piston only, sporty-
comfortable tuning Rebound in ‘Spor t ’ mode –
working piston only, sporty-
hard tuning
Compression in ‘Normal’ mode –
working piston and bypass, sporty-
hard tuning
Porsche Active Suspension
Management (PASM).
The optional PASM is an elec -
tronic damping control system.
On the Boxster models, the
suspension has been tuned to
match the high power of the
engine. PASM actively and con -
tinuously regulates the damping
force for each wheel according
to the road conditions and driving
st yle. In addition, the suspension
is lowered by 10 mm.
The driver can select bet ween
t wo dif ferent modes: ‘Normal’
which is a blend of performance
and comfort, and ‘Sport ’ where
the setup is much firmer. The
PASM control unit evaluates the
driving conditions and modifies
the damping force on each of
the wheels in accordance with
the selected mode.
Sensors monitor the movement
of the vehicle body, for example,
under heav y acceleration and
braking or on uneven roads. The
control unit tunes the dampers
to the optimum hardness for the
selected mode to reduce roll and
pitch still further and to increase
contact bet ween each individual
wheel and the road.
In ‘Sport ’ mode, the suspension
is set to a harder damper rating.
On uneven roads, PASM imme-
diately switches to a softer
rating within the ‘Sport ’ setup
range, thereby improving con-
tact bet ween the wheels and the
road. When the road surface
improves, PASM automatically
reverts to the original, harder
rating.
If ‘Normal’ mode is selected and
the driver’s st yle becomes more
assertive, PASM automatically
switches to a harder rating within
the ‘Normal’ setup range.
Damping becomes harder, and
driving stabilit y and road safet y
are increased.
Mechanically locking rear
differential.
Are you a fan of sport y driving?
In your spare time, do you
enjoy the occasional outing on
the racetrack? Then you
shouldn’t do without the optional
mechanically locking rear differ -
ential available in conjunction
with 18-inch or 19-inch wheels.
It further enhances the traction
of the driven rear wheels on
uneven roads and when acceler -
ating out of tight bends. Road
holding at the limits of perform -
ance is even more impressive.
The car holds its course bet ter
and so PSM intervenes less often.
In other words, sheer driving
pleasure and faster lap times.
