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The SF90 Stradale not only is Ferrari’s first-ever plug-in hybrid, it’s also marks the first Ferrari sportscar to be fitted with all-wheel-drive. (Ferrari)
 

Ferrari reveals SF90, first-ever plug-in hybrid

Storied sportscar-maker Ferrari will produce its first-ever plug-in hybrid-electric vehicle, the company said in announcing its SF90 Stradale, a new model named in reference to the 90th anniversary of Ferrari’s founding. But not only is it the brand’s first PHEV, it’s the most powerful Ferrari production car ever sold.

And for yet another “first,” the SF90 Stradale is the first Ferrari sportscar to be fitted with all-wheel drive (AWD), “a step necessary to allow the incredible power unleashed by the hybrid powertrain to be fully exploited,” Ferrari reported.

 “The new model is extreme on every level and represents a true paradigm shift because it delivers unprecedented performance for a production car,” Ferrari said in a release announcing the car, also confirming that with the inception of the SF90 Stradale, “a V8 is the top-of-the-range model for the first time in the marque’s history.”

The SF90 Stradale combines the output of a 4.0-L (3990-cc) twin-turbocharged V8 (essentially derived from Ferrari’s much-awarded 3.9-L twin-turbo V8) and three electric motors—a motor/generator between the engine and the transmission driving the rear wheels and a motor for each wheel at the front axle, which in true “e-axle” configuration is not mechanically connected to the internal-combustion driveline. The arrangement is central to imparting the sophisticated AWD propulsion that combines control of the two front-axle traction motors with the IC/motor-driven rear wheels.

The SF90 Stradale’s performance is little short of astounding—even by Ferrari standards. The company claims a 0-62 mph (97 km/h) acceleration time of 2.5 s and says the car can hit 124 mph (200 km/h) in 6.7 s, while top speed is a titanic 211 mph (340 km/h).

Despite the added weight of three motors and a 7.9-kWh lithium-ion battery pack—total hybrid system weight is 270 kg (595 lb.)—Ferrari said the 2-seat SF90 Stradale’s curb weight is just 1570 kg (3461 lb.).

Eight cylinders for the primary job
The SF90’s 4.0-L 90-degree V8, developing 769 hp at 7,500 rpm, has the highest output ever for a Ferrari V8, the company said. Although the engine’s bore was increased to 88 mm compared with the original 3.9-L variant, the SF90’s engine has a narrower cylinder head larger intake valves and a 9.5:1 compression ratio. A new direct-injection fueling system with central injectors works at 350 bar (5076 psi) and the company said the intake and exhaust are completely redesigned; redline is 8000 rpm.

The turbochargers now have electronically-controlled wastegates which enhance catalyst heating and new compressor volutes that optimize flow dynamics.

Ferrari claims the 4.0-L V8’s 192.27 hp per liter specific output is the highest in the segment.

Revised gear ratios for the 8-speed automated manual deliver an 8% efficiency improvement in the Worldwide Light Vehicle Test Procedure (WLTP) cycle, Ferrari said, adding that although the transmission adds a ratio, its installed height is 15 mm (0.6 in) lower and overall is 10 kg (22 lb.) lighter, in part owing to the fact that it includes no reverse gear—that function now is provided by the front-axle motors.

Electro-drive tricks
Another new-to-Ferrari curiosity for the SF90 Stradale: when driven exclusively on battery power, the Stradale is a front-wheel drive car.

Top speed exclusively on battery power is 135 km/h (84 mph) and 25 km (16 miles) is the maximum range from the 162 kW (217 hp) of combined power from the three electric motors that also can feed as much as 800 Nm (590 lb-ft) into the propulsion equation.

The hybrid system also plays into another famous Ferrari attribute: braking. Although providing genuine performance “feel” has been difficult to achieve with brake-by-wire systems, the company says the SF90 Stradale has brake-by-wire control that “allows the braking torque to be split between the hydraulic system and the electric motors” and goes on to say the design “actually boosts performance and brake feel rather than compromising them.”

Multi-material body and structure
The new SF90 Stradale stays relatively light with new innovations such as hollow castings in place of conventional ribbed castings. Two new aluminum alloys are used in the car, including a high-strength 7000-series alloy “for some of the sheetmetal,” the company said, and carbon fiber is used for the bulkhead separating the engine from the the cabin. The company said that the SF90 Stradale’s chassis has 20% increased bending stiffness and 40% higher torsional rigidity than previous platforms without any increase in weight.

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