· 44 ·· 45 ·
Under oil pressure, clutch 1
closes and forms a frictional
connection with input shaf t 1.
The torque is now transmit ted
through the first half gearbox
– and then the dif ferential – to
the rear axle. At this stage,
PDK has already preselected
the next gear in the second
half gearbox. Engine torque
is already acting on the other
outer disc carrier and, in
response to a gear change
signal, the overlap shift is initi -
ated, i.e. as clutch 1 opens,
clutch 2 closes. The non-positive
connection with input shaft 2
is
established, and power is
trans
mit ted to the wheels.
The gear which is engaged is
displayed on the instrument
cluster.
Depending on the gearshift
programme, the gear change
is optimised for comfort or for
sport y handling and takes place
in a mat ter of milliseconds.
The advantage over a fully manual
transmission is the considerably
faster rate of acceleration for the
same rate of fuel consumption.
Boxster | Drive
The advantage over a fully auto -
matic transmission
is the per -
ceptible increase in driving
dynamics – with a similar level of
comfort, and a distinct reduction
in fuel consumption.
The com -
pact dimensions of the gearbox
reduce rotational
masses which
means a more direct engine
response, and the system is
more lightweight.
PDK function diagram
This, along with the long-ratio
7th gear, helps to achieve
reduced fuel consumption and
emission figures comparable with
those of a manual gearbox.
With the optional Sport Chrono
Package, PDK is enhanced by
the
‘Launch Control’ and ‘motor-
sport- derived gearshif t strategy’
functions (p. 57). In essence, PDK combines sport
i
-
ness with efficiency and comfort.
What does all this mean for you?
Uninterrupted driving pleasure.
Multi-plate clutch 1
Multi-plate clutch 2
Semi -gearbox 2
(2nd, 4th, 6th gear)
Rear semi-gearbox 1
(1st, 3rd, 5th, 7th, R gear)
Differential
Motor
Rear wheel
Rear wheel
Boxster
· 50 ·· 51 ·
Boxster and Boxster S
Suspension.
The suspension of the Boxster
models has been tuned to match
the high performance of the
engines.
Light weight coil- over McPherson
struts are combined with lateral
control arms to ensure excellent
driving dynamics and safet y on
all road surfaces. The axle kine-matics are designed for high
performance, as is the generous
wheel track. Light weight con
-
struction throughout keeps the
overall weight and unsprung
masses low, with almost all mov -
ing parts made from aluminium.
The mid-engine design, in com -
bination with the complex chassis
technology, results in minimum
roll and pitch movements on
cornering, braking and accel -
eration.
The chassis of the Boxster
models ensures high safet y
reserves irrespective of load,
and easily controllable load
transfer when cornering. Corner -
ing stabilit y is exemplary, even
in high-speed bends. The same
applies to straight-line stabilit y.
Steering.
What use is a perfect suspension
setup without perfectly tuned
steering? For Porsche, this would
be inconceivable. The solution
is a steering system which is as
precise and immediate as the
chassis itself and, thanks to the
power assistance, steering ef fort
is reduced to a comfortable
level. Around the straight-ahead
position, such as during motor -
way driving, the ratio is less
direct but with no loss of agilit y
or feedback.
Boxster | Chassis
The greater the steering angle,
the more direct the steering
ratio. This is particularly notice-
able when turning tight corners
or parking. The car has a turning
circle of just 11.1 m.
Front axle with McPherson struts and lateral control arms (Boxster S)
Rear axle with McPherson struts and lateral control arms (Boxster S)
