Porsche 911 Turbo User Handbook Manual page 30

Porsche Stability Management (PSM).
Enhanced stability control for the 911 Turbo.
Porsche Stability Management oversteer or understeer, PSM
(PSM) is an automatic vehicle applies selective braking on
stability control system designed individual wheels to restore stability
to aid the driver in critical road and optimum speed. Whenever
scenarios. Specially revised for the PSM is required to intervene, an
911 Turbo, it uses a range of indicator light in the cockpit
sensors to monitor the direction, flashes.
speed, yaw velocity (speed of
rotation around the vertical axis) When accelerating on wet or other
and lateral acceleration of the low-grip surfaces, PSM combines
car. Using this information, it is with PTM and uses the automatic
possible to calculate the actual brake differential (ABD) and anti-slip
direction of travel at any given regulation (ASR) functions to
moment. If the car begins to maintain traction and stability.
Included as standard equipment,
PSM assists with high-precision
inputs that enhance the agility
of each model. When 'Sport'
mode is selected on the optional
Sport Chrono Package Turbo
(see page 70), the PSM threshold
is raised higher still to enable
greater driver involvement –
particularly at speeds of up to
70 km /h (44 mph).
PSM includes ABS to help minimise
braking distances. System
inputs are smooth and precise for
greater driver comfort. Active
safety is further enhanced with the
aid of two additional brake
functions: electronic brake prefill
and brake assist.
The prefill function is automatically
enabled whenever the throttle
pedal is suddenly released.
The pressure in the brake lines is
marginally increased, bringing
each of the pads into light contact
with the corresponding disc. If the
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Oversteer without PSM
Oversteer
without PSM
Car steers
off line
Understeer without PSM
Understeer
without PSM
Car steers
off line
driver then decides to use the The result: shorter braking
brakes, the system can apply distances.
the maximum force with virtually
no delay. If you'd rather drive without PSM,
the system can be manually
The brake assist function is disabled. PSM remains present in
specifically designed for use in the background and will only
emergency stops. When the intervene under heavy braking
pressure on the brake pedal where at least one front wheel
exceeds a predefined threshold, requires ABS assistance. The
the PSM hydraulics automatically automatic brake differential (ABD)
apply the necessary pressure remains active at all times. In
to achieve maximum deceleration. 'Sport' mode on the optional Sport
911 Turbo |
Oversteer with PSM
PSM corrects
direction and
stabilises car
Understeer with PSM
PSM corrects
direction and
stabilises car
Chrono Package Turbo, PSM
will only respond when ABS
assistance is required on both
front wheels.
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Chassis