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Understanding the Vehicle
The system will not activate if the
transmission is placed in N (Neutral) or P
(Park) mode.
Active Steering Torque (AST)
The AST function integrates the ESC
system with the electric power steering
to increase the safety level of the whole
vehicle.
In critical situations (braking on surfaces
with different grip conditions), through
the AST function, the ESC system
controls the steering to implement an
additional torque contribution on the
steering wheel, to suggest the most
correct manoeuvre to the driver.
The coordinated action of the brakes
and steering increases the sensation of
safety and control of the car.
Limited Slip Differential
(LSD)
In standard configuration the car is
equipped with transmission with a
mechanical Limited Slip Differential
(LSD). An electronic version of the LSD is
available as an optional.
Mechanical Limited Slip
Differential
The mechanical self-locking differential
is used to limit the wheelspin of the
internal wheel when accelerating out of
corners and to stabilize the rear axle
when braking.
Electronic Limited Slip
Differential
With the electronic self-locking
differential the lock percentage is not
fixed but varies progressively with a
continuous control from 0 - 100 %.
The locking percentage is managed by
electro-hydraulic actuators controlled by
an electronic control unit integrated in
the vehicle’s dynamics control system.
On the basis of the information received
from the engine, transmission, steering,
and brake sensors it decides both when
and how much to lock the differential,
with very high actuation speeds (up to
100 ms).
All this makes it possible to obtain
and guarantee greater traction during
acceleration, as well as high precision,
stability and maneuverability when
entering corners.
When cornering, the electronic LSD can:
• stabilize the vehicle when the
accelerator pedal is released by locking
the rear axle;
• control vehicle dynamics by locking the
differential proportionally in relation to
lateral acceleration and vehicle speed;
• maximize both vehicle stability and
acceleration when cornering by locking
the differential proportionally in relation
to lateral acceleration, speed, selected
gear and torque produced by the
engine.
To obtain these results, the LSD system
interacts with the ESC and ABS systems,
dual clutch transmission and suspension
damping control.
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