VDI AWARDS 29
Car of the Year
Some fantastic vehicles have been launched over the past 12 months,
but which vehicles most impressed the jury with their dynamics setup?
This year saw a very close-fought battle between Porsche’s
992 and Ferrari’s SF90 Stradale. Ultimately Ferrari won,
with a model that is unusual in many ways for the
marque, being a V8 rather than the V12 traditionally
fi tted to its fl agship models, as well as being its fi rst
series production PHEV – and it also brings in several
vehicle dynamics innovations.
The car is extreme on every level, with headline
fi gures of 1,000cv, a weight-to-power ratio of 1.57kg/
cv, and 390kg of downforce at 250km/h (155mph).
Ferrari’s engineers have fi tted a 4WD system to help
drivers exploit the full power of the hybrid powertrain,
with the traction enabling yet more impressive fi gures, of
0-100km/h (62mph) in 2.5 seconds and 0-200km/h (124mph)
in 6.7 seconds.
The SF90 Stradale is not just about straight-line power though, as
Ferrari’s dynamics engineers have introduced a full-electric front axle,
known as the RAC-e (electronic cornering set-up regulator). As well
as exclusively providing propulsion in electric drive, the two front
motors independently control the torque delivered to the wheels, for
a ‘torque vectoring’ effect. The RAC-e is integrated into the vehicle
dynamics controls, and by governing the distribution of torque, the
car becomes easier to drive on the limit.
The braking performance is also impressive, with Ferrari’s brakecooling
circuit design completely redesigned for the SF90. Ferrari’s
engineers collaborated with Brembo to develop a new caliper design
for the front brakes, and this is its fi rst application on a road car. The
caliper has an integrated aerodynamic appendage, which distributes
the highly charged air fl ow from the air intake to the brake pads and
discs more effi ciently.
However, all these dynamics features, as well as the 270kg hybrid
architecture, create a weight penalty. This weight has been offset
by the all-new chassis and bodyshell, built using multi-material
technology including carbon fi bre, two new aluminium alloys, and
the use of hollow castings instead of ribbed castings. The result is an
overall vehicle weight of 1,570kg, and the design also brings benefi ts
in terms of rigidity and a lower centre of gravity, with the chassis
boasting 20% higher bending stiffness and 40% higher torsional
rigidity than previous Ferrari platforms. NVH characteristics have
also been improved through the use of a new alloy known as ‘quiet
aluminium’ for the fl oor pan.
The high-voltage system controls (battery, RAC-e, MGUK, inverter),
engine and gearbox control, and vehicle dynamics controls (traction,
braking, torque vectoring) have been integrated with Ferrari’s
existing vehicle control logics, to create what the company has
named the eSSC (electronic side slip control) vehicle control system.
The eSSC introduces three dynamic regulation and distribution
strategies for sending engine torque to all four wheels: Electric
Traction Control (eTC), which optimally manages the availability
of the torque and distributes it to the individual wheels to suit
driving conditions and grip requirements; brake-by-wire control
with ABS/EBD, which allows the braking torque to be split between
the hydraulic system and the electric motors to allow regenerative
recovery under braking; and torque vectoring.
May/June 2020 • VehicleDynamicsInternational.com
• Porsche 992 Carrera
• Land Rover Defender
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• Ford Focus ST
• Audi RS 6 Avant