Ferrari SF90 XX – The first road going XX options

Based on the SF90 Stradale, the new special limited series SF90 XX Stradale will be built in just 799 and 599 examples respectively, these new V8-powered PHEVs represent the latest and most extreme example of a concept of special versions, which pushes the performance of Ferrari’s road-going models to new levels.

Ferrari’s XX Programme offers a select group of expert client drivers extreme cars that are not homologated for the road, but that can be driven at the very limit on the track. All of the models produced by the programme have proved a huge success, with the most recent addition being the FXX-K EVO.

Ferrari decided to create a road-legal car which embodies the maximum expression of the two programmes’ engineering concepts. The SF90 XX Stradale is based on the supercar in the range, the SF90 Stradale, and raises its already impressively exhilarating track and on-the-limit driving experience to new heights.

The focus with the SF90 XX Stradale’s development was to produce the most high-performance Ferrari road car ever that also delivered maximum fun behind the wheel, whilst fully retaining all of the functionalities of the SF90 Stradale’s hybrid powertrain. Usability of performance was especially important, particularly in terms of the electric mode’s ability to deliver surprisingly high-performance driving both in typically urban settings and in out-of-town trips.

The same concept provided the inspiration for the SF90 XX Spider, which combines the ultimate on- track adrenaline rush with the heady pleasure of open-air driving, where the iconic sound of the Ferrari V8 gives such a vital contribution. The SF90 XX Spider benefits from the same sophisticated aero solutions as the SF90 XX Stradale, as well as specifically developed cockpit air flows that guarantee superb occupant comfort with the top down. It is equipped with Ferrari’s acclaimed retractable Hard Top (RHT), which comprises aluminium panels and not only deploys and retracts in a mere 14 seconds, but can also be activated at speeds of up to 45 km/h.

Performance is boosted thanks to its impressive 1,030 hp (30 more than the SF90 Stradale), specific software logics and the use of radical new aerodynamics solutions, including a fixed rear spoiler – the first to appear on a road-going Ferrari since the days of the F50 – The car also has a specific front splitter, which is larger than the SF90 Stradale’s, and is the result of meticulous work in the wind tunnel. It generates a highly energised tube of air flow under the car, and this is then exploited by the redesigned underbody. A larger, wider front diffuser contributes to the increase in downforce culminating in the SF90 XX Stradale achieving an unparalleled 530 kg of downforce at 250 km/h.

The car has a set-up with elastic characteristics and kinematic angles designed solely to optimise its behaviour on the limit. There is a 9% improvement in lateral performance compared to the SF90 Stradale in high-speed handling conditions, mostly because of downforce. Furthermore, the roll rate was reduced by 10% thereby guaranteeing better body control.

The SF90 XX Stradale has also inherited the signature PHEV layout found in the SF90 Stradale and SF90 Spider, Like the SF90 Stradale, the SF90 XX Stradale has three electric motors, one located between the V8 and the gearbox and two on the front axle. In this instance, they deliver a maximum of 233hp or 171 kW, thanks to the patented extra boost vehicle dynamics logic, an absolute first on a Prancing Horse road car. The SF90 XX Stradale’s high performance lithium-ion battery powers the three motors, guaranteeing a 25km range in full-electric mode. When the V8 is off, the front motors give the car a maximum speed of 135 km/h.

The transition from electric mode to hybrid mode is extremely smooth thanks to the seamless coordination between the electric front axle, the 8-speed DCT gearbox, the rear-mounted electric motor and the V8 engine. This in turn guarantees progressive, continuous acceleration and makes all the powertrain’s power available as rapidly as possible. 

The V8 benefits from improved cooling thanks to the fact that the front radiators for the high temperature cooling circuit are more efficient. The new layout of the underbody was also optimised to guarantee improved extraction of the air coming off the radiators ahead of the front wheels. The side louvres on the lower part of the front bumper, already seen on the SF90 Stradale, were also redesigned and are now larger to reduce backpressure.

The simultaneous increase in power and downforce posed a new challenge which Ferrari’s engineers tackled by reversing the layout of the medium temperature radiator, tasked with cooling the electrical components, increasing its efficiency, and enclosing a part of the car’s underbody, thereby increasing the effective surfaces that would help generate frontal downforce. It should come as no surprise that this very clearly race-derived architecture is shared by the brand-new 296 GT3.

The positioning of the front radiator has improved the aerodynamics simultaneously channelling hot air through and over the front bonnet. These flows are controlled and channelled over the car by two S-Ducts located one on either side of the vents in the centre of the bonnet also helping to increase frontal downforce by 20%.

At the rear of the car, a scoop in front of the entry to the intercooler air intake cleans and directs the air flow to the radiators. When the car is moving, cool air is drawn into the engine compartment through three apertures: the first located above the intercooler intake on the side and the second crossways on the engine cover, while the third is a pair of ducts located to the sides of the struts of the fixed spoiler.

The SF90 XX Stradale’s soundtrack was redesigned to become the ultimate encapsulation of the car’s racing soul. To produce an even fuller, richer sound and celebrate the harmonics right across the V8’s rev range, The use of innovative materials improved the acoustic clarity of the system: the result is a wonderfully rich explosion of an iconic Ferrari V8 sound. 

The driver can use the eManettino selector on the steering wheel to choose from four different power management modes. In eDrive mode, the internal combustion engine is turned off and traction is entrusted entirely to the front axle; Hybrid mode, favours battery power and manages transitions autonomously, maximising the full-electric range, whilst performance mode keeps the lusty V8 on priority for breath-taking performance.  Which will see this technical masterpiece vaporise the distance to the 100kph marker in just 2.3s!

The SF90 XX Stradale and the SF90 XX Spider retain the 8-speed dual-clutch gearbox that made its first appearance in the Ferrari range on the SF90 Stradale. However, the gear-shift logic has changed significantly: the car uses the patented logic introduced on the Ferrari Daytona SP3 to deliver an even more engaging dynamic acceleration response, accompanied by an intoxicating exhaust note mimicking the overrun lift-off noise typical of high-performance driving.

The Torque Vectoring and Energy Recovery under braking and lift-off functions are available in all modes, introducing Ferrari Dynamic Enhancer active in all dynamic Manettino selections and all grip conditions. The various systems all managed by Ferrari’s electronic Side Slip Control (eSSC) 1.0.

Another major new addition is the ABS EVO controller, which debuted on the 296 GTB. Thanks to its integration it improves both performance and consistency during high performance braking. Functioning in high grip situations the system leverages sensor data to obtain a precise reading on the vehicle’s speed. This makes it possible to determine the optimal target slip of all four wheels for optimal brake force distribution.

The resulting outcome allows the longitudinal force of the four tyres to be better exploited both in straight line braking and during turn-in, where the rear axle must deliver a natural trade-off between longitudinal braking performance and lateral stability.

In addition to this, also debuting on SF90 XX Stradale is the extra boost control logic which guarantees additional power in short bursts. When in Qualifying mode it produces an extra boost of power at the critical moment when the car is exiting a bend, helping further improves lap times The logic controls the power delivery, managing peak performance with battery charge, also monitoring the status of the components with the aim of optimising electric power delivery. The availability of the extra boost is indicated by a graph on the right-hand side of the dash display and shows the remaining number of bursts left (maximum 30).

Generating significantly more downforce than the SF90 Stradale and consequently the SF90 XX Stradale’s braking system was also upgraded. While it retains the Aero callipers at the front, the front discs have been completely redesigned to improve cooling, there are now bigger 390mm-diameter rear discs, and the brake pads are a new design that maximise the contact surface to improve bite on the discs during rapid deceleration.

The SF90 XX Stradale is the most extreme version of the SF90 Stradale; its design criteria are based on a track car, yet it’s been refined and calibrating for exhilarating on road driving. The SF90 XX Stradale is not just a special version: it is the first XX model to pass through the factory gates, to truly encapsulate the very pinnacle of Prancing Horse racetrack technology, aerodynamic efficiency and power, into a road vehicle.

Designed by the Ferrari Styling Centre headed by Flavio Manzoni, the SF90 XX Stradale incorporates the engineering principles that underpinned the SF90 Stradale and pushes them to new extremes. Thanks to the close synergic relationship between the Styling Centre and the Technical Department, significant modifications were carried out, with the aim of increasing the downforce of the original car.

The SF90 XX Stradale’s styling cues are designed to highlight its thoroughbred performance characteristics whilst still retaining the pure lines and forms of its predecessor. Hence the decision not to hide air intakes and vents, a fundamental part of racing cars’ stylistic language. A technical solution that also becomes a signature element: the three louvres on the SF90 XX Stradale’s front wing and on the rear one are an example of this.

There is no doubt that one of the most distinctive characteristics of the SF90 XX Stradale’s design is its rear wing. The tail volume, which has been specifically redesigned with aero in mind, is now sleeker, giving it the long tail silhouette typical of racing cars. The air intakes for the intercoolers are now larger too, channelling the air towards the radiators more efficiently.

The headlights, which now have an even lower upper profile, new and distinctive elements of the front section are the two imposing lower wings that dominate the air intakes, which look as if they are floating, making the SF90 XX Stradale itself seem broader and embedding its grip on the road surface.

The rear of the car is characterised by the trimaran design of the tail. Compared to the SF90 Stradale, the SF90 XX Stradale features more imposing rear vents behind the wheels. The trimaran section also incorporates two central exhausts. Design-wise, the aim here was to visually underscore the impressive width of the rear of the car and this was achieved by drawing on a layering concept.

One of the layers is the fixed rear wing, a solution not seen on a street legal Ferrari since the 1995 F50. The second is the body-coloured profile that wraps around a light-bar, an element that is a complete departure from the twin-taillight concept of the SF90 Stradale. The third layer, already seen on the SF90, is the blown spoiler combined with an active aero concept known as a shut-off Gurney.

Carbon-fibre elements stand out from bodywork colour elements all over the car, but most especially in its lower section, to underscore the car’s technical aspects. Other connotative elements are the air vents in the shape of rounded-off quadrangles on both the front bonnet and rear engine lid, which effectively become a part of the car’s livery. They are designed as touches of colour that coordinate with the end plates on the carbon-fibre rear wing. The car also sports specific star-burst wheel rims with prominent aerodynamic profiles.

The guiding principle of the SF90 XX Stradale’s interior design was highlighting the cockpit’s racing vocation through clever design that would provide significant weight-savings. The main areas were the door panels, tunnel and mats, which are now simpler in terms of their shape and the mainly technical fabrics used, while carbon-fibre was used for functional areas. The upper part of the dashboard is trimmed in Alcantara®, while the lower part is trimmed in technical fabric. Both are inspired by the racing world.

The door panels emphasise the theme seen aboard the SF90 Stradale: the concave sections that converge on the dashboard are highlighted by the colour contrast. The three louvres in the middle zone, on the other hand are a nod to the air vents on the wheel arch, creating an overall dynamic, sculptural effect. The three apertures, which reference the exterior language, also seamlessly integrate both vehicle technical and control functions.

The pared-back central tunnel is dominated by the gear shift gate which is located now centrally and more forward on the tunnel compared to the SF90 Stradale. A specific racing seat with a visible carbon-fibre tubular structure and cushion supports was designed for the car to enhance sporty driving pleasure without compromising on comfort.

The create a seamless visual structure the backrest rake mechanism has been integrated into the seat using elastic trim materials which hide the separation between the backrest and seat squab just like a single-piece seat while also allowing the backrest to be adjusted. Together with the carbon-fibre structure, this feature saved and additional 1.3 kg in weight.

The SF90 XX Spider allowed the Ferrari Styling Centre to use the modifications made to the rear of the car to create an instantly recognisable architecture in which the flying buttress, a much-loved part of Ferrari tradition, seamlessly melds with the arrow theme of the front. The resulting visual effect extends the body forwards and lending it a completely different connotation to the SF90 XX Stradale.

The car’s centre of gravity thus appears to be lower too, particularly from the side. This is not just because of the roof, which has a wraparound windscreen that seamlessly melds with the side windows, but also because the flying buttresses are lower than on the SF90 XX Stradale. Although the rollbars protrude from the rest of the bodywork when the roof is lowered, the fact that they are carbon-fibre means they don’t sully the broad, squat look created by the flying buttresses. This in turn enhances the visual lowering of the car’s volume.

When the roof is up, the rollbars seamlessly connect to and become one with the roof structure. Like the rollbars, the top is carbon-fibre and thanks to the renowned Ferrari Retractable Hard Top (RHT) mechanism, can be opened while the car is moving in a mere 14 seconds at a speed of up to 45 km/h, allowing occupants to enjoy the car to the utmost in all kinds of weather.

Now the difficult choice which one will you choose.