What Makes It the Fastest Ferrari Road Car Ever?
“On the road, things happen much faster than on the 488 Pista,” says Raffaele de Simone, test driver for the 2021 Ferrari SF90 Stradale. “Train your neck and your reactions,” he said, hinting. that the new high-tech 986-horsepower hypercar from Ferrari will generate truly prodigious grip levels while feeling as fast and agile as a racing car. “You can cross corners so much faster.”
The SF90 is a benchmark Ferrari. It is the most powerful Ferrari road car to date. It is also the fastest, with an acceleration time from 0 to 60 mph claimed under 2.5 seconds, the sprint from 0 to 124 mph taking only 6.7 seconds. So far, so Maranello … But that’s where it gets really interesting. The SF90 is the first flagship Ferrari since the F40 not to have a V-12 engine. In addition, it is also the very first Ferrari hybrid plug-in, the first Ferrari with all-wheel drive with central engine, the first Ferrari to use wire braking technology and the first Ferrari sports car equipped with electric power steering.
That smell? Tradition, smoldering in a dumpster. It might have the old-fashioned nose-up horse shield on the front fenders and the drive selection buttons arranged in a structure on the center console designed to resemble the iconic metal gearbox, but the SF90 is truly a Ferrari of the here and now, a road car clearly developed by a company whose Formula 1 team is part of its internal expertise in design and engineering and not the result of an expensive sponsorship contract . “It represents the pinnacle of what Ferrari can do,” said Matteo Turconi, SF90 product manager.
Let’s take a closer look.
The Ferrari SF90 Stradale rechargeable hybrid powertrain
The SF90’s hybrid powertrain includes a half-power V8 twin-turbo engine developing 769 hp and 590 lb-ft of torque, three electric motors and a high-voltage half-power battery. An electric motor is mounted between the engine and the new eight-speed dual-clutch automatic transmission and develops 157 hp and 196 lb-ft of torque. The other two electric motors are mounted on the front axle, driving the front wheels, and each develop 97 hp and 62 lb-ft of torque. The liquid-cooled 8 kW-h single module battery weighs just 158 pounds, and allows the SF90 to travel up to 15 miles with pure power, using the front motors, at speeds up to 84 mph.
Although the SF90’s V-8 is part of the F154 family of engines, which debuted in the California T and was used in the 488 and F8 Tributo, it has been significantly improved. The new cylinder heads feature redesigned combustion chambers with centrally mounted injectors that provide a 7% increase in combustion pressure, increasing power. As a result, the capacity increased slightly from 3.9 liters to 4.0 liters.
Other changes include a new crank, new connecting rods, new pistons, new camshafts, a new intake system – the plenums are almost bolted to the heads – and a new exhaust. The turbos are the same size as on the F8 Tributo, but the revised compressor rollers facilitate increased air flow. The new parts reduce the engine weight by 55 pounds and have reduced the overall height by 12 percent, helping to lower the car’s center of gravity.
Nicknamed the “pizza engine” by Ferrari engineers, the main electric motor, called P1, is sandwiched between the rear of the V-8 internal combustion engine and the front of the new eight-clutch dual-clutch transmission. reports. Ferrari says the axial flow technology used in the engine is a world first in terms of the production car. An axial flow motor means that the disc-shaped rotors are mounted coaxially on either side of a flat stator (conventional electric motors have a rotor that rotates inside a tubular stator). In the Ferrari engine, the rotors consist of a stainless steel substrate, an iron laminate and a network of magnets bonded to them. At just 2.8 inches deep and weighing 48 pounds, the P1 electric motor is extremely power dense, capable of producing 157 hp and 196 lb-ft of torque.
The two electric motors driving the front wheels of the SF90, called P4, are of conventional design, with rotors wound in a hairpin rotating inside a fixed stator housing. “It is a relatively proven technology, but which has evolved to allow small diameters and high speeds,” says powertrain director Vittorio Dini. The water-cooled engines weigh only 26 pounds each and will run at 25,000 rpm. They drive the front wheels through what Ferrari describes as “a cascading cylindrical and planetary gear train” that allows the engines to propel the SF90 at 84 mph in pure electric power mode, with each wheel’s torque to vary independently. , and for the two e-motors to be disengaged at speeds above 130 mph. The SF90 is therefore a car with front wheel drive, all wheel drive or rear wheel drive, depending on the driving mode and driving conditions.
The SF90’s eight-speed dual-clutch transmission is brand new and will eventually appear in the Ferrari lineup. It was designed to allow the engine to sit lower in the chassis than the seven-speed used in the F8 Tributo and can support 96 lb-ft of additional torque. Larger eighth gear reduces fuel consumption by 5%, and a dry sump oil system that allows one oil to be used for lubrication and hydraulic actuation instead of the two oils used in the seven speeds, reduced it by 3 percent. The new transmission is also 15 pounds lighter overall than the old seven-speed, but Ferrari has reduced it by an additional 6 pounds in the SF90 by removing the reverse play; select reverse and the front electric motors push the car back.
In addition to a new transmission, the SF90 launches a digital dashboard and a driver interface that will also appear in future Ferraris. The centerpiece of the system is a fully configurable digital dashboard on a 16-inch full HD curved free-form screen. An industry first, explains Maximilian Romani, head of HMI and ergonomics at Ferrari. The screen is flanked by pods that are within easy reach of the steering wheel. The touch controls on the right module regulate the HVAC functions; those on the left pod are for the light and the exterior mirrors. A head-up display, the smallest ever developed for a sports car, says Ferrari, projects information in high resolution on the windshield.
“Eyes on the road, hands on the wheel.” This is the mantra behind the development of the new driver interface system, says Ferrari, and a new steering wheel with capacitive touch switches and a small touchpad is an integral part of the system. There is no on / off button. Just double-tap the icon above the third spoke, and the SF90 is ready to slide on its electric motors, with hybrid mode being the default driving mode. Romani says that compared to an 812 Superfast, the new interface reduces the time it takes the driver to look away from the road and the time it takes to complete a task by 36%.
The now familiar Ferrari driving mode switch Manettino is in its usual place, just at the bottom right of the steering wheel boss. But the PHEV powertrain on the SF90 adds an extra layer of complexity and capacity to the menu. These additional modes are controlled by a group of touch switches just below the steering wheel boss nicknamed eManettino.
The eDrive mode of the SF90 means that the Ferrari will only run on the front electric motors. Hybrid mode is the default setting, with computers switching power flows between the V8 biturbo and electric motors as appropriate. Performance mode keeps the internal combustion engine running at all times to keep the battery charged and electrical power instantly available. And the qualification mode will ensure that the powertrain provides the full power of 986 hp as long as there is a charge in the battery. That’s good for about six or seven laps of the Ferrari Fiorano test track or a lap of the 12.9-mile Nürburgring Nordschleife, says Stefano Varisco, responsible for vehicle dynamics.
Aerodynamics and SF90
To optimize the shape of the SF90 not only for performance, but also for the operation of hybrid and electric motors and to assist in the thermal management of the PHEV powertrain, Ferrari spent 50% more time in the wind tunnel perfecting the aerodynamics than with the LaFerrari. “It is the most aerodynamically efficient car in the Ferrari range,” explains Matteo Biancalana, aerodynamics manager. At the front, the central intake cools the front electric motors, while the inlets on each side are for cooling the V-8 engine. Borrowing from F1 experience, the front floor has been raised by 0.6 inches to accommodate larger vortex generators under the car, increasing the downforce on the front axle by 30%.
The most innovative aerodynamic element is at the rear of the car. In normal low-drag mode, air flows over the cabin and exits through a vent between the rear lights. In high downforce mode, the central element of the wing descends and stops this flow, creating a giant Gurney flap. The patented system would develop 860 pounds of downforce at 186 mph. Replacing the center element for low-drag mode requires less effort, says Ferrari, because it essentially floats on the air flow and the engineers were able to reduce the weight of the actuators by 66%.