Bugatti Bolide – The new Projectile from Molsheim
Barely two years since the launch of the Bugatti Divo, Molsheim’s 1,500 PS handling masterpiece, the French brand presents the Bolide, a 1,850 PS track-focused hyper sports car, designed with the legacy of the Type 35 and it’s 2,000 victories in mind.
The Bolide is built around the iconic W16. The 8.0-litre W16-cylinder engine with 1,850 PS and 1,850 newton-metres of torque was designed specifically for use on the racetrack. Both the engine and gearbox are optimised for higher engine speeds.
Among other things, this includes dethrottling the intake and exhaust system to achieve an even faster, more spontaneous response. The four newly developed turbochargers are fitted with optimised blades, in order to build up more compression and deliver increased power at higher engine speeds.
For optimum lubrication, even under extremely high centrifugal forces, the oil circuit, oil pressure, check valves, baffles, oil tanks, oil reservoirs and pump design of the dry sump lubrication have all been redesigned, while there have been significant weight savings of the drive system.
Monocoque and design features
But bringing the weight down to 1,250kg (75kg less than a VW Polo) is no easy feat. All the screw and fastening elements of the Bolide are made completely out of titanium. In addition, hollow, thin-walled functional components made of an aerospace titanium alloy are employed in many design features. These components are manufactured using a 3D printer and have a wall thicknesses of up to 0.5 millimetres. Nevertheless, they are very stable and have a tensile strength of 1,250 newtons per square millimetre.
Hybrid components, such as the 0.5- metre-long auxiliary drive shaft, combine wound high-strength and ultra-stiff carbon fibres with 3D-printed titanium end fittings. They can withstand a continuous operating temperature of up to 260 degrees Celsius and lead to a reduction in weight by roughly 1kg. This weight-reduction of the rotating masses, significantly increases the rotational response of the engine.
The forces acting on the front and rear wings are transferred by ultralight, yet very solid titanium elements. They weigh a mere 600 grams at the front and 325 grams at the rear.
A worldwide innovation is the morphable outer skin of the intake scoop on the roof, which provides active airflow optimisation. If the vehicle is driven at a slow speed, the surface of the scoop remains smooth. In contrast, a field of bubbles bulges out when driven at fast speeds. This reduces the aerodynamic drag of the scoop by 10 percent and ensures a 17 percent reduction in lift forces.
Moreover, the flow onto the rear wing is optimised. At 320 km/h, the downforce is 1,800 kilograms at the rear wing and 800 kilograms at the front wing.
As in Formula 1, the Bolide decelerates with ceramic racing brakes. The brake callipers weigh only 2.4 kilograms each. The front forged magnesium rims with central lock weigh 7.4 kilograms, while the ones at the rear weigh 8.4 kilograms – with a very wide tyre size of 340 millimetres on the front axle and 400 millimetres on the rear axle. In comparison, the Chiron has 285 mm at the front and 355 mm at the rear.
A GT/LMP standard compressed-air-driven jack system with four rams makes tyre changing easier, while a quick refuelling system allows pressure refuelling.
Among other things, a push rod kinematics system with horizontal dampers ensures precise handling. The oil reservoirs are arranged inside the dampers, which improves aerodynamics. Weighing only 100 grams, the push-rods are designed as a thin-walled and flow-optimised titanium lightweight construction with a buckling load of 3.5 tonnes, roughly the dry weight of two Chirons.
Finally, The welded control arms are made of aerospace-grade stainless steel, have a tensile strength of 1,200 newtons per square millimetre and are also designed as wing profiles.
The Bugatti team developed a light monocoque made of carbon around the drive. The integral front end flanged to it is also made of high-strength carbon fibres, as are the fully aerodynamically effective underbody and the monocoque itself.
The carbon-fibres used on the Bolide are employed in the aerospace industry and have a single-fibre tensile strength of 6,750 newtons per square millimetre, while the single-fibre stiffness is 350,000 newtons per square millimetre.
The rear frame, designed as a welded steel assembly, offers a maximum tensile strength of 1,200 newtons per square millimetre, despite a wall thickness of only 1 millimetre – this is made possible by the use of high-strength stainless steel, which is otherwise only used in aviation.
With an overall height of only 995 millimetres, the Bugatti Bolide is exactly the same height as the historic Bugatti Type 35, depending on the steering wheel and truncated windscreen, and about 300 millimetres flatter than the Chiron.
The wheelbase is 2.75 metres and the width 1.99 metres. Like in an LMP1 racing car, the occupants fold up the doors that are hinged at the front at an angle, sit on a sill that is only 70 millimetres wide, as in a Type 35, and then position their feet in the interior. Thanks to a side wall that is about 150 millimetres lower than that of the Type 35, the procedure is quick and easy – for drivers up to a body height of 2 metres!
Safety is ensured, with safety equipment designed in accordance with FIA regulations. These include HANS device compatibility, an automatic fire extinguishing system, a towing device, pressure refuelling with fuel bladder, central locks for the wheels, lightweight polycarbonate windows and a six-point harness system.
The monocoque side floors with integrated carbon coolant pipes are simultaneously designed as side impact structures and structural reinforcement of the monocoque. The driver can see all the relevant data on a motorsport display. For an optimum sitting position, both the pedals and the passenger footrest can be moved by 150 millimetres.
The Design Team
The experimental study of the Bugatti Bolide is also a very special project for Achim Anscheidt, Director of Design at Bugatti. “In my 16 years at Bugatti, I have never worked on a more extreme concept.” The design of the Bolide is radically tailored to the idea of lightweight construction, and the design principle therefore follows on from the overriding goal of achieving a fascinating weight-to-power ratio of 0.67 kilograms per PS.
“It is the very first time that my team had the freedom of creating an absolutely minimalistic design around the W16 engine. The result is the most provocative proportion of a modern Bugatti ever and the distilled quintessence of our Bugatti design ethos that form follows performance,” says Anscheidt. “The Bugatti Bolide, however, is a project more technically driven than shaped by style.”
The stylistic challenge was to transform the unyielding demands of aerodynamics and lightweight construction into an aesthetic that reflects the unique Bugatti DNA, but at the same time illustrates the ambition of an impressive weight-to-power ratio. The overall appearance is dominated by air ducts that are more reminiscent of aerodynamically sophisticated Formula 1 racing cars than classic sports cars. The seemingly filigree and half-open front end is a striking example of the combination of air duct expertise, lightweight construction requirements, and aesthetic dynamics.
The dramatic effect of the overall proportions is made clear by the aerodynamically favourable overall height of only 995 millimetres. The driver’s ultra-sporty seating permits the low-slung shape of an automotive low-flying aircraft. It is therefore not surprising that the appearance of the Bugatti Bolide invokes the so-called X-planes of aviation history and shows a clear X signature from every perspective. It is indirectly reminiscent of the Bell X-1 jet aircraft which was flown by Captain Charles “Chuck” Yeager 1947, the first person to break the sound barrier at Mach 1.06. The Bugatti Bolide “X-periment” has the shape of an aerodynamically optimised, uncompromising racing car and offers ultra-sporty, superlative performance – with no hint of luxury.
As with other Bugatti vehicles, the Bugatti design team also makes use of a colour split in the Bolide. Compared with other models, the share of visible carbon parts is increased by up to 60 percent. Only around 40 percent of the surfaces are painted – in a re-interpretation of the historic French Racing Blue.
“Fifteen years ago, Bugatti succeeded in creating a new segment with the Veyron 16.4: that of the superior hyper sports car. With the Chiron launched in 2016, we systematically developed this segment further. The models bear witness to power and elegance, uniquely combining technology, design, luxury, and quality in a hitherto unknown combination,” explains Anscheidt. “In contrast, the Bugatti Bolide is an absolute rebel. It is clear to see that its only aim is to convey the pure power of the W16 engine in a visually and technically unadulterated form. Reduced, raw, and authentic – like freshly-caught sashimi”.
Bugatti was never a conventional automotive manufacturer. In recent years, the company has progressed along the lonely path of peerless excellence, distancing itself from commercial priorities set by some of the world’s most esteemed supercar brands. The Bugatti Bolide is testament on this commitment and a promise for things to come.