Porsche 911 Carrera 4 Brochure & Specs page 34

A strong character knows when to take a back seat.
Porsche Stability Management (PSM).
PSM is an automatic control direction of motion. If this
system for providing stability direction deviates from the
at the limits of dynamic driving desired course, PSM initiates
performance, and is a standard braking interventions targeted
feature of every 911. Sensors at individual wheels – recog-
work continuously to monitor the nisable by the flashing indicator
driving direction, speed, yaw light in the cockpit – in order to
velocity and lateral acceleration stabilise the vehicle.
of the car. Using this infor-
mation, PSM computes the actual
911 Carrera S Cabriolet
Under acceleration on wet or low-
grip road surfaces, PSM improves
traction using the ABD (automatic
brake differential) and ASR (anti-
slip regulation) functions. The
control interventions are smooth
and precise, giving an agile
response. When 'Sport' mode is
selected on the optional Sport
Chrono Package Plus (p. 74),
Oversteer without PSM
Vehicle yaw/
course deviation
Understeer without PSM
Vehicle yaw/
course deviation
the PSM intervention threshold is If the driver suddenly releases
raised to enable greater driver the accelerator pedal, PSM
involvement – particularly at automatically readies the braking
speeds of up to approximately system. With the braking system
70 km/h (45 mph). having been precharged, the
brake pads are already in light
The integrated ABS shortens the contact with the brake discs.
braking distance even further Maximum braking power is there-
and the braking inputs are smooth fore achieved much sooner.
and precise, thereby enhancing
comfort. When sudden braking is detected
– i.e. if the pressure on the brake
An enhanced PSM system is pedal exceeds a predefined level
characterised by two additional – the brake assist function uses
functions: the precharging of the the PSM hydraulics to apply
brake system, and brake assist. maximum brake pressure to all
four wheels.
The 911 |
Oversteer with PSM
Correction to
vehicle course
deviation and
stabilisation
Understeer with PSM
Correction to
vehicle course
deviation and
stabilisation
If you want a purely active driving
experience, you always have the
option to deactivate PSM. It is
automatically reactivated, for
your safety, if either of the front
wheels (in sport mode, both of
the front wheels) requires ABS
assistance. The ABD function,
however, remains active at all
times.
In conclusion, PSM offers a high
level of driving stability and
safety – and typical Porsche
agility at the same time.
Chassis