As a result, the Chiron Pur Sport runs with extreme precision. “The driver knows in advance exactly where the Chiron Pur Sport is going, so only minimum steering movement is required. This precision and predictability make driving easier, significantly increasing driving pleasure,” explains Jachin Schwalbe. Due to the new, softer tires for increased road grip at the limit of driving dynamics, the negative camber, and the significantly higher downforce, the Bugatti engineers decided to limit the top speed to 350 km/h. “In return, the Chiron Pur Sport offers exceptional road grip over the entire speed range,” says Jachin Schwalbe. Of course, this extremely sporty handling has to function on all roads and offer passengers sufficient comfort – whether on the Nordschleife or in city traffic. More than 50,000 test kilometers are required for chassis fine-tuning alone: the Chiron has now completed well over a million test kilometers in total. “The combination of a firmer chassis, shorter gear ratio, more downforce, and the new ESC-Sport+ driving mode is addictive. The Chiron Pur Sport selects the right gear in every situation, no matter how dynamic. It feels like it’s glued to the road. Then you’ve got this tremendous acceleration. The car exceeds the expectations of even the most experienced drivers,” explains Jachin Schwalbe.
15 percent shorter gear ratio
The seven-speed dual-clutch transmission has undergone a radical transformation: the Bugatti engineers shortened each gear and modified many components. All in all the gears have been shortened by 15 percent. The Chiron Pur Sport accelerates from 0 to 100 in 2.3 seconds instead of 2.4 seconds, and from 0 to 200 in 5.9 instead of 6.1 seconds. Moreover, it accelerates in sixth gear from 60 to 120 km/h in 4.4 seconds instead of 7.4. The vehicle's top speed is now electronically regulated at 350 km/h, with a maximum shift speed of 6,900 rpm. In order to align the shift points with the new gear ratios and altered shift speed, the shift strategy was subjected to extensive revision. Upshift and downshift control is perfectly adapted in all gears according to engine speed and load points. “We spent one and a half years developing the control system so as to ensure that every shift really does fit exactly in all driving conditions. First in simulation, then on the test stand and finally on a test and circuit tracks as well as on country roads and motorways,” says Carl Heilenkötter, transmission development engineer at Bugatti. “Now everything is perfect!” Every driver will immediately feel that the engine revs up faster, the gears are closer together and the gearbox shifts more quickly. One particular challenge according to Heilenkötter is to reach maximum shift speed just before the rev limiter intervenes so as to get as much power as possible from the engine to the road, especially in the event of a slip and in all temperatures. Drivers who wish to shift gear themselves will use the easy to grab extended shift paddles behind the steering wheel.
High-revving W16 engine
To ensure the engine and gearbox harmonize perfectly with the modified ratios in all engine speed ranges, Bugatti has also refined the W16 engine with its 1,500 PS and 1,600-newton meters of torque. The 8.0-liter power unit now reaches its rated output between 6,700 and 6,900 rpm – in other words, it revs 200 rpm higher than the engine in the Chiron. The maximum engine speed is now 7,000 rpm. “This nominal output plateau with the extended rev range allows longer availability of maximum power, enhancing the sense of emotion and sportiness. The driver immediately feels the engine speed dynamics with the higher tractive force,” says Michael Gericke, engine developer at Bugatti. The gears are changed at an even faster rate. This is why the four turbochargers have to be accelerated all the time: here the engineers also had to retune the wastegate valves for boost pressure control. The W16 engine has been assigned new values for each of the seven gears. As a result, the Chiron Pur Sport accelerates in sixth gear from 60 to 120 km/h almost three seconds faster than the Chiron – which is already very fast. All in all, elasticity is 40 percent higher than in the Chiron.
Tires with extremely high grip