Ferrari’s first series production PHEV, the SF90 Stradale, was unveiled in the UAE at Casa Ferrari – the perfect destination for Ferraristi to enjoy the best possible experience at the Abu Dhabi Formula One Grand Prix 2019.
The new model is extreme on every level and represents a true paradigm shift, because it delivers unprecedented performance for a production car. Figures such as 1,000 cv, and a weight-to-power ratio of 1.57 kg/cv, and 390 kg of downforce at 250 km/h not only put the SF90 Stradale at the top of its segment, but also mean that a V8 is the top-of-the-range model for the first time in the marque’s history.
The car’s name encapsulates the true significance of all that has been achieved in terms of performance. The reference to the 90th anniversary of the foundation of Scuderia Ferrari underscores the strong link that has always existed between Ferrari’s track and road cars. A brilliant encapsulation of the most advanced technologies developed in Maranello, the SF90 Stradale is also the perfect demonstration of how Ferrari immediately transitions the knowledge and skills it acquires in competition to its production cars.
The SF90 Stradale has a 90° V8 turbo engine capable of delivering 780 cv, the highest power output of any 8-cylinder in Ferrari history. The remaining 220 cv is delivered by three electric motors, one at the rear, known as the MGUK (Motor Generator Unit, Kinetic) due to its derivation from the Formula 1 application, located between the engine and the new 8-speed dual-clutch transmission on the rear axle, and two on the front axle. However, this sophisticated system does not make for a more complicated driving experience. Quite the opposite, in fact: the driver simply has to select one of the four power unit modes, and then just concentrate on driving. The sophisticated control logic takes care of the rest, managing the flow of power between the V8, the electric motors and the batteries.
The SF90 Stradale is also the first Ferrari sports car to be equipped with 4WD, a step necessary to allow the incredible power unleashed by the hybrid powertrain to be fully exploited, ensuring the car has become the new benchmark for standing starts: 0-100km/h in 2.5 sec and 0-200km/h in barely 6.7 seconds.
Ferrari’s engineers were able to further broaden the spectrum of dynamic controls by introducing the 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 two wheels, extending the concept of Torque Vectoring. Fully integrated into the car’s vehicle dynamics controls, the RAC-e governs the distribution of torque, making driving on the limit much simpler and easier.
The introduction of this hybrid architecture was a challenge with regard to managing the additional weight, which was resolved by an obsessive attention to detail and the overall optimisation of the whole of the car. For maximum performance in terms of overall weight, rigidity and centre of gravity, the chassis and bodyshell of the SF90 Stradale is all new, built using multi-material technology, including, for example, carbon fibre.
The development of a hybrid car of this kind demanded the development of a series of innovative aerodynamic solutions. The significant boost in the power unit’s performance brought with it an increase in the amount of heat energy to be dissipated and required the development team to carry out an in-depth review of the aerodynamic flows on the radiating masses. It also demanded new solutions to increase downforce efficiently and guarantee maximum stability at all speeds and in all driving conditions.
Particularly noteworthy is the innovative shut-off Gurney, a patented active system located at the rear of the car, which regulates the air flow over the upper body, reducing drag at high speeds with low lateral dynamics loads and increasing downforce in corners, under braking and during changes of direction.
The new car is epoch-changing from a stylistic perspective as it completely rewrites the mid-rear-engined sports berlinetta proportions introduced on the 360 Modena twenty years ago, instead taking its inspiration from Ferrari’s recent supercars. A good example is the cockpit, which has a smaller frontal section and is placed closer to the front of the car to reduce drag. This was also achieved without impacting on-board comfort.
The track-derived “eyes on the road, hands on the wheel” philosophy takes on a truly central role for the first time too, significantly influencing the ergonomics and styling of the interior. The result is an HMI (Human-Machine Interface) and interior layout concept that are a complete departure from previous models.
Another major innovation is the steering wheel which now has a touchpad and a series of haptic buttons that allow the driver to control virtually every aspect of the car using just their thumbs. The central instrument cluster is now entirely digital with the first automotive application of a 16” curved HD screen, which can be fully configured and controlled using the controls on the steering wheel.
On the central tunnel, improved ergonomics have been combined with an element from the past: the automatic gearbox controls are now selected by a grille-style feature that references Ferrari’s legendary manual gear-shift gate. Thus past and present skilfully merge to point the new Ferrari towards the future.
The SF90 Stradale also sees the debut of the new ignition key with full keyless technology, which will gradually be introduced across the rest of the range, personalised with the model’s name. Thanks to a special compartment in the central tunnel, it becomes an integral part of the car’s styling.
In addition to the sporty version, which references the shape and colour of the signature rectangular Prancing badge sported by Ferrari’s road cars, there will also be a more elegant metal-coloured version.
For the first time on a Ferrari, clients can chose between the standard car and a version with a more sports-oriented specification. The Assetto Fiorano specification includes significant upgrades, including special GT racing-derived Multimatic shock absorbers, extra lightweight features made from high-performance materials such as carbon-fibre (door panels, underbody) and titanium (springs, entire exhaust line), resulting in a weight-saving of 30 kg. Another difference is the high downforce carbon-fibre rear spoiler, which generates 390 kg of downforce at 250 km/h. The Assetto Fiorano includes Michelin Pilot Sport Cup2 tyres designed specifically to improve performance on the track in the dry. They feature a softer compound and fewer grooves than the tyres provided as standard.
The SF90 Stradale is the first ever Ferrari to feature PHEV (Plug-in Hybrid Electric Vehicle) architecture which sees the internal combustion engine integrated with three electric motors, two of which are independent and located on the front axle, with the third at the rear between the engine and the gearbox.
The internal combustion engine and the electric motors work in synergy to unleash an incredible 1,000 cv which means the SF90 Stradale sets a whole new benchmark in terms of its performance and innovative content not just with regard to the Ferrari range, but also its competitors.
Internal Combustion Engine
Thanks to its 780-cv power output, the turbo V8 featured in the SF90 Stradale raises the bar for the performance limits achievable by this type of architecture. The starting point was the F154 family engine which has won the International Engine of the Year award for the fourth consecutive year, an unprecedented achievement for any power unit.
Together with its 195 cv/l specific power output, which is the highest in the segment, the engine also delivers 800 Nm of torque at 6,000 rpm. To deliver this extraordinary result, Ferrari’s engineers focused on several different areas of the engine, starting by increasing its capacity from 3,902 cc to 3,990 cc thanks to a larger bore of 88 mm.
The intake and exhaust system was completely redesigned and now features a new, narrower cylinder head with a central injector and the adoption of 350-bar GDI, another first for a Ferrari V8.
To improve the internal fluid dynamics, not only was a larger diameter intake valve adopted but the ducts are all horizontally lined up at engine head height; the turbo charger assembly has been lowered while the exhaust line is higher, as testified by the fact that the tail pipes are now in the upper section of the rear bumper. The turbos are now equipped with electronically-controlled wastegates to improve catalyser heating and new compressor volutes to optimise fluid-dynamics.
The re-engineering goes well beyond fluid-dynamics: the rationalisation of the layout has resulted in both a lower centre of gravity, thanks in part to the adoption of a smaller-diameter fly wheel, and a reduction in overall weight thanks to the use of Inconel instead of steel for the exhaust manifold. Meticulous attention was lavished on sound quality when redesigning the exhaust system and the result is fuller, richer harmonics across the entire frequency range.
The SF90 Stradale sports a completely redesigned 8-speed, oil-bath, dual-clutch transmission. New gear ratios and improved transmission efficiency yield a significant reduction in fuel consumption in urban and motorway driving (-8% in the WLTP cycle) without having to compromise on performance. In fact, there is even a 1% improvement in efficiency on the track.
An optimised layout, achieved through the adoption of a dry sump and a significantly more compact clutch assembly with a 20% smaller exterior diameter than the current gearbox, has shaved 15 mm off the installed height in the car which, in turn, lowers the centre of gravity of the running gear by the same amount.
Despite the addition of an eighth gear and a maximum torque boost to 900 Nm (the latter an increase of 20% on the current 7-speed), the gearbox’s overall weight is actually 7 kg lower. That figure rises to 10 kg when the elimination of the reverse gear – now incorporated in the function of the front electric motors – wheels is included.
The new clutch’s performance is 35% higher, transmitting up to 1200 Nm in dynamic torque in gear shifts. Thanks to new-generation actuation hydraulics, total clutch fill times have been cut to 200 ms compared to the 488 Pista’s 300 ms.
The SF90 Stradale is equipped with three electric motors capable of generating a total of 220 cv (162 kW). A high performance Li-ion battery provides power to all three motors and guarantees a 25-kilometre range in all-electric eDrive mode, using just the front axle. When the internal combustion engine is turned off, the two independent front motors deliver a maximum speed of 135 km/h with longitudinal acceleration of ≤0.4 g. Reverse can only be used in eDrive mode, which means the car can be manoeuvred at low speeds without using the V8. The front motors are integrated into the launch control strategy for maximum performance when accelerating.
Ferrari’s engineers chose to put the battery pack immediately behind the seats, just above the chassis rear cross member, rather than going for the classic layout in which the batteries would be sunken into the floor pan. This guaranteed the best possible packaging, with a short wheelbase for handling and lower weight, limiting the impact on the centre of gravity.