Ferrari unveils HY-KERS hybrid system in the limited series 950 hp LaFerrari

6 March 2013

Ferrari’s limited-series special hybrid (499 units) unveiled at the Geneva Motor SHow, the LaFerrari, introduces a hybrid system exploiting the experience of the Scuderia Ferrari’s F1 KERS. Although aimed at collectors, said Luca di Montezemolo, Ferrari President, the technology will “find [its] way into the rest of the range.”

LaFerrari on the stage. Click to enlarge.

The application of HY-KERS on LaFerrari is without an electric-only drive mode—something that “would not fit the mission of this model”, Ferrari said. However, the HY-KERS system is designed so that in future applications a car can be driven using exclusively electric power for a few kilometers. During development testing, a LaFerrari with HY-KERS with a full-electric mode achieved 220 g/km of CO₂ emissions on the combined cycle.

Powertrain. The LaFerrari is the first Ferrari to be powered by the HY-KERS system. The engine is a 789 hp (800 CV) 6262cc V12 that revs to a maximum of 9,250 rpm, a record for an engine of this displacement. It also features a very high 13.5:1 compression ratio and a high specific output equal to 126 hp per liter. The engine is coupled with a 120 kW electric motor, giving the vehicle a combined power output of 950 hp.

The high torque levels available at low revs from the electric motor allowed the engineers to optimise the internal combustion engine’s performance at higher revs, thus providing a constant supply of exceptional power throughout the rev range. Total torque generated is in excess of 900 N·m (663 lb-ft).

The hybrid system is composed of two electric motors developed in collaboration with Magneti Marelli—one powering the driven wheels and the second the ancillaries—and a battery pack attached to the floor of the chassis consisting of cells that are assembled in the Scuderia Ferrari department where the KERS for the F138 is also made. The Scuderia’s expertise allowed considerable savings in weight and size of the individual components; the battery pack weighs 60 kg (132 lbs).

The batteries are charged in different ways: under braking (even hard braking with the ABS active) and every time the V12 produces more torque than required, such as in cornering. In the latter instance, rather than the being sent to the wheels, the excess torque is converted to energy and stored in the batteries.

The electric motor is coupled with the F1 dual-clutch gearbox to the benefit of optimal weight distribution, but also to boosting energy efficiency as torque is instantly available to the wheels and, vice versa, from the wheels to the electric motor in recharging.

Aerodynamics. Active aerodynamics allow adjustment of the car’s configuration. To boost efficiency, the LaFerrari features active aerodynamic devices front (diffusers and guide vane on the underbody) and rear (diffusers and rear spoiler) which generate downforce when needed without compromising the car’s overall drag coefficient. These devices deploy automatically on the basis of a number of different performance parameters which are monitored in real time by the car’s dynamic vehicle controls, thus guaranteeing an optimized configuration on the basis of the driving conditions.

Control systems. LaFerrari integrates its active aerodynamics and hybrid system with the other dynamic control systems aboard. Proprietary Ferrari algorithms integrated the electric motor and V12 for instantaneous response. In cornering, for instance, the HY-KERS keeps the V12’s revs high to guarantee better acceleration on exit.

The LaFerrari’s Brembo braking system is also integrated with the hybrid system, and incorporates several new features, including new lightweight calipers designed to guarantee correct cooling and carbon-ceramic material (CCM) discs featuring a new composition.

The car’s extreme performance potential called for a different tire set-up, with 265/30 R 19 Pirelli P-Zeros on the front and 345/30 R 20s on the rear.

The LaFerrari accelerates from 0-100 km/h in less than 3 seconds and 0-200 km/h in under 7 seconds. The car has delivered a lap time at Fiorano of below 1’20”—5 seconds faster than the Enzo and more than 3 seconds faster than the F12berlinetta.

Architecture. The aim of the design of LaFerrari was to achieve ideal weight distribution (59% at the rear) and a compact wheelbase despite the extra bulk of the hybrid system. The result is that all of the masses are situated between the car’s two axles and as close as possible to the floor to lower its center of gravity (by 35 millimeters) and thereby guarantee dynamic handling and compact dimensions.

The layout of the cabin made a significant contribution in this. The seat is fixed and tailored to the driver while both the pedal box and steering wheel are adjustable. The driving position is similar to that of a single-seater and was designed after consultation with the Scuderia Ferrari drivers, Fernando Alonso and Felipe Massa, who played an active role throughout the entire development process.

The LaFerrari’s chassis features four different types of carbon-fibre, all hand-laminated and autoclave-cured in the racing department using the same design and production methods as the Formula 1 car. This helped optimize the design: various functions were integrated (e.g. seats and battery compartment) into the chassis to improve torsional rigidity (+27%) and beam stiffness (+22%) while cutting weight.