The FXX K is the successor to the Ferrari FXX (based on the Enzo Ferrari), with the "K" representing the kinetic energy recovery system (KERS). While based on the LaFerrari, Ferrari claims that the FXX K is a completely new model.
Although it is based on the LaFerrari, the folks from Maranello consider the FXX K to be its own model. The XX designation is more than a car, it’s a program that enables owners to race their cars at exclusive events with full factory support. The K is for the KERS system that contributes 187 additional electrical prancing horses to the total output of well over 1,000 hp. To keep the FXX K stable, it is capable of creating more than half a ton of downforce through its active-aero systems; the coolest of which are the winglets that are joined by a rear spoiler that raises on vertical stabilizers. Is it the ultimate Ferrari? If going five seconds faster than the LaFerrari at the (Fiorano) test track is a measure, well… what do you think?
— Forzamotorsport.net description for Forza Motorsport 6
The 6.3L (6,262 cc) naturally aspirated V12 engine, codenamed F140 FE, now pumps out 848 hp (860 PS; 632 kW). The HY-KERS unit has also been tuned to produce 187 hp (190 PS; 139 kW). In total, the FXX K produces a massive power output of 1036 hp (1050 PS; 773 kW), but otherwise still has the LaFerrari's 664 ft·lb (900 Nm) of torque. The FXX K is capable of creating more than 1190 lb (540 kg) of downforce at 224 mph (360 km/h) thanks to its improved active aerodynamics. It features winglets joined by a rear spoiler that raises on vertical stabilizers.
The Ferrari FXX K is currently the best-performing pre-tuned Ferrari car in the series, capable of outstanding handling that surpasses those of most other cars, quick acceleration (0-100 mph in 4.5 seconds), and excellent braking. The FXX K doesn't suffer from a lot of wheelspin when accelerating from a stop at full throttle, allowing better launches than most rear-wheel-drive cars.
It creates so much downforce it sticks to corners easily and doesn't require a lot of time and distance to brake to low speeds. The FXX K's biggest disadvantages, on the other hand, are its slow acceleration to speeds beyond 174 mph (280 km/h), especially in the highest gear, and its above-average top speed. In Forza Horizon 3, the FXX K can hit a top speed of only 214 mph (344 km/h).
Because of these drawbacks, despite the FXX K's superb handling and braking, it is unable to beat cars like the Koenigsegg One:1 or Ultima Evolution Coupe 1020 on medium/long-length tracks due to both cars having the ability to reach 200 mph (322 km/h) much faster. Strangely, only because of its better braking, the FXX K can outlap the McLaren P1 GTR, contradicting what is expected of these two cars if the McLaren P1 can beat the Ferrari LaFerrari. The FXX K, in summary, is the fastest non-racing Ferrari and is suited for tracks with many complex corners and with a lack of long straights.
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