The Bugatti Veyron EB 16.4 is the most recent version of a mid-engined full-sized grand tourer developed by the German car-manufacturer Volkswagen and produced by the Volkswagen-brand Bugatti Automobiles SAS at their headquarters in Château St. Jean in Molsheim (Alsace, France), and whose production and development is often credited to Ferdinand Karl Piech. It is named after French racing driver Pierre Veyron, who won the 24 hours of Le Mans in 1939 while racing for the original Bugatti company. It was named “Car Of The Decade” by the BBC television programme Top Gear.
Two hundred and twenty Veyrons are known to have been built and delivered since production began in 2005 and ended in late 2008. Special variants of the Veyron include the Pur Sang, the Fbg Par Hermes, the Sang Noir, the Targa, the Vincero, and the Bleu Centenaire. It will be replaced with the Grand Sport, which is essentially a Veyron convertible.
Key Specifications and Performance
The Veyron features an 8.0 litre W16 engine — sixteen cylinders in two banks of eight cylinders, or the equivalent of two narrow angle V8 engines mated in a “W” configuration. Each cylinder has four valves for a total of sixty four, but the narrow staggered eight configuration allows two overhead camshafts to drive two banks of cylinders so only four camshafts are needed. The engine is fed by four turbochargers and displaces 7,993 cubic centimetres (487.8 cu in), with a square 86 mm by 86 mm (3.4 in × 3.4 in) bore and stroke.
The transmission is a dual clutch Direct-Shift Gearbox computer-controlled automatic with seven gear ratios, with magnesium paddles behind the steering wheel and a shift time of less than 150 milliseconds. This is designed and manufactured by Ricardo of England (and not Borg-Warner who designed the six speed DSG used in the mainstream marques of the Volkswagen Group). The Veyron can be driven in either semi automatic or fully automatic mode. A replacement transmission for the Veyron costs just over $120,000. It also features fulltime permanent four wheel drive, using the Haldex Traction system. It uses special Michelin PAX run flat tyres, designed specifically for the Veyron to accommodate its top speed, which reportedly cost $25,000 US per set. The tyres can only be removed from the rims in France, a service which reportedly costs $70,000. Kerb weight is 2,034.8 kilograms (4,486 lb). This gives the car a power to weight ratio, according to Volkswagen Group’s 736 kilowatts (1,001 PS; 987 bhp) figures, of 446.3 bhp per ton.
The car’s wheelbase is 2,710 mm (106.7 in). Overall length is 4,462 mm (175.7 in), width 1,998 mm (78.7 in) and height 1,204 mm (47.4 in).
The Veyron’s hydraulic rear spoiler in the extended position
The Bugatti Veyron has a total of ten radiators.
- 4 radiators for the engine cooling system.
- 1 heat exchanger for the air to liquid intercoolers.
- 2 for the air conditioning system.
- 1 transmission oil radiator.
- 1 differential oil radiator.
- 1 engine oil radiator.
It has a drag coefficient of 0.41 (normal condition) and 0.36 (after lowering to the ground), and a frontal area of 2.07 square metres (22.3 sq ft). This gives it a CdA ft² value of 8.02.
Engine output
According to Volkswagen Group, the DIN rated motive power output, approved by TÜV Süddeutschland, of the final production Veyron engine produces 1,001 metric horsepower (736 kW; 987 bhp) and generates 1,250 newton metres (922 ft·lbf) of torque. The figure has been confirmed by Bugatti officials to actually be conservative, with the real total being 1020 bhp or more.
Top speed
The top speed was verified by James May on Top Gear for the November 2006 issue, again at Volkswagen Group’s private Ehra-Lessien test track, where the final-production car hit 407.9 km/h (253.5 mph), which equated to almost one-third of the speed of sound at sea level. As the Bugatti Veyron approached the top speed during the test, May said that “the tyres will only last for about fifteen minutes, but it’s okay because the fuel runs out in twelve minutes”. He also gave an indication of the power requirements: at a constant 155 mph, the Veyron is using approximately 270 metric horsepower (200 kW; 270 bhp); the next 100 mph requires an additional 730 metric horsepower (540 kW; 720 bhp). Jeremy Clarkson, driving a Veyron from Italy to London, noted that at top speed, the engine consumes 10,000 imperial gallons (45,000 L) of air per minute (as much as a human breathes in four days). With a 0 to 60 time of 2.4 seconds, the Veyron was the fastest legal street car between the years 2005 and 2007. Once back in the Top Gear studio, May was asked by co-presenter Jeremy Clarkson what the Veyron felt like to drive at 407 km/h (253 mph), May replied that it was “totally undramatic”, and very stable at speed.
German inspection officials recorded an average top speed of 408.47 km/h (253.81 mph)[19] during test sessions on the Ehra-Lessien test track on 19 April 2005. The Bugatti website still refers to the Veyron as the fastest production vehicle of all time even though this title has since been taken by the SSC Ultimate Aero TT.
The car’s everyday top speed is listed at 350 km/h (220 mph). When the car reaches 220 km/h (140 mph), hydraulics lower the car until it has a ground clearance of about 9 cm (3.5 in.). At the same time, the wing and spoiler deploy. This is the “handling mode”, in which the wing helps provide 3,425 newtons (770 lbf) of downforce, holding the car to the road, and helping the Bugatti Veyron perform 1.34 g forces on a 300 foot skidpad.[13] The driver must, using a special key (the “Top Speed Key”), toggle the lock to the left of his seat in order to attain the maximum (average) speed of 407 km/h (253 mph). The key functions only when the vehicle is at a stop, when a checklist then establishes whether the car and its driver are ready to enable ‘top speed’ mode. If all systems are go, the rear spoiler retracts, the front air diffusers shut and the ground clearance, normally 12.5 cm (4.9 in), drops to 6.5 cm (2.6 in).
Braking
The Veyron’s brakes use cross drilled, radially vented carbon fibre reinforced silicon carbide (C/SiC) composite discs, manufactured by SGL Carbon, which have a much greater resistance to brake fade when compared with conventional cast iron discs. The lightweight aluminium alloy monobloc brake calipers are made by AP Racing; the fronts have eight titanium pistons and the rear calipers have six pistons. Bugatti claims maximum deceleration of 1.3 G on road tyres. As an added safety feature, in the event of brake failure, an anti-lock braking system (ABS) has also been installed on the handbrake.
Prototypes have been subjected to repeated 1.0 G braking from 312 km/h (194 mph) to 80 km/h (50 mph) without fade. With the car’s acceleration from 80 km/h (50 mph) to 312 km/h (194 mph), that test can be performed every 22 seconds. At speeds above 200 km/h (120 mph), the rear wing also acts as an airbrake, snapping to a 55-degree angle in 0.4 seconds once brakes are applied, providing an additional 0.68 G (4.9 m/s²) of deceleration (equivalent to the stopping power of an ordinary hatchback). Bugatti claims the Veyron will brake from 400 km/h (250 mph) to a standstill in less than 10 seconds.
How actually does a Veyron V-16 Works?
The Bugatti Veyron is a car built around an engine. Essentially, Bugatti made the decision to blow the doors off the supercar world by creating a 1,000-horsepower engine. Everything else follows from that resolution.
So let’s start with the engine. How would you begin the design process for an engine this powerful? If you have know how a car engines works, you know that if you want to create a 1,000-horsepower engine, it has to be able to burn enough gasoline to generate 1,000 horsepower. That works out to about 1.33 gallons (5 liters) of gasoline per minute.
How much gas is that?
- 1,000 horsepower is equivalent to roughly 2.6 billion joules per hour. A gallon (3.8 liters) of gasoline contains 132 million joules, so a 1,000-hp engine has to be able to burn just over 20 gallons of gasoline per hour.
- However, car engines are only about one-quarter efficient — three quarters of the gasoline’s energy escapes as heat rather than as power to the wheels. So the engine actually has to be able to burn at least 80 gallons per hour, or 1.33 gallons (5 liters) per minute.
- Let’s convert over to metric. Gasoline requires about 14.7 kilograms of air to burn 1 kilogram of gas. Air weighs 1.222 kilograms per cubic meter at sea level. A gallon of gasoline weighs 2.84 kilograms. So the engine has to be able to process 2.84*1.33*14.7 kilograms of air per minute, or roughly 45 cubic meters of air per minute. That’s 45,000 liters of air per minute.
- If a V-8 engine is turning at 6,000 rpm, it can inhale a total of 24,000 cylinders’ full of air per minute. If it needs to inhale 45,000 liters of air per minute, it works out to roughly 2 liters per cylinder-full. That’s a 16-liter engine.
We need a 16-liter engine to burn 1.33 gallons of gas per minute. That actually makes sense — the engine in the Dodge Viper is 8.0 liters in displacement and produces 500 hp.
But there’s a problem: A 16-liter V-8 engine would be very large. And the pistons would be massive, so there would be no way it could turn at 6,000 rotations per minute (rpm). It might turn at a maximum of 2,000 rpm, meaning that you would need an immense 48-liter engine to generate 1,000 hp. Clearly an engine that big is impossible in a passenger car.
So how did Bugatti fit 1,000 horsepower into a passenger car?
Bugatti did two things to create a compact engine capable of producing 1,000 hp.
The first and most obvious thing is turbocharging.
The Bugatti Veyron’s 16-cylinder monster engine produces 1,001 horsepower for a top speed of more than 250 mph. And it’s a passenger car. Check out the Bugatti. Amazing isn`t it? If you have know how a turbocharger works, you know that one easy way to make an engine more powerful without making the engine bigger is to stuff more air into the cylinders on each intake stroke. Turbochargers do that. A turbo pressurizes the air coming into the cylinder so the cylinder can hold more air. If you stuff twice as much air in each cylinder, you can burn twice as much gasoline. In reality, it’s not quite a perfect ratio like that, but you get the idea. The Bugatti uses a maximum turbo boost of 18 PSI to double the output power of its engine. Therefore, turbocharging allows Bugatti to cut the size of the engine from 16 liters back down to a more manageable 8 liters. To generate that much air pressure, the Bugatti requires four separate turbochargers arranged around the engine.
The second thing Bugatti engineers did, both to keep the RPM redline high and to lower lag time when you press the accelerator, was to double the number of cylinders.
The Bugatti has a very rare 16-cylinder engine.
There are two easy ways to create a 16-cylinder engine.
- One way would be to put two V-8 engines in-line with each other. You connect the output shaft of the two V-8s together.
- Another would be to put two in-line 8-cylinder engines beside one another.
The latter technique is, in fact, the way Bugatti created its first 16-cylinder cars in the early 20th century.For the Veyron, Bugatti chose a much more challenging path. Essentially, Bugatti merged two V-8 engines onto one another, and then let both of them share the same crankshaft. This configuration creates the W-16 engine found in the Veyron. The two V’s create a W.
Special Features
The special features of the Bugatti W-16 engine are amazing. For example:
- The engine has four valves per cylinder, for a total of 64 valves.
- It has a dry sump lubrication system borrowed from Formula 1 race cars, along with an intricate internal oil path to ensure proper lubrication and cooling within the 16 cylinders.
- It has electronically controlled, continuously variable cam timing to create optimal performance at different engine rpm settings.
- It has a massive radiator to deal with all of the waste heat that burning 1.33 gallons of gasoline per minute can generate.
Everything about the engine is superlative.And it is remarkably compact. It measures just 710 mm (27 inches) long, 889 mm (35 inches) wide and 730 mm (28.7 inches) high. This is the beauty of Bugatti’s W-16 approach — the engineers managed to fit 1,000 hp into a reasonably sized package.
Transmission
The transmission is unique, in particular because it has to harness about twice as much torque as any previous sports-car transmission. It has:
- Seven gears
- A dual clutch system
- Sequential shifting
- A paddle-driven, computer-controlled shifting system
This computer-controlled system is identical to the sort of system found in a Formula 1 car or a Champ car. There is no clutch pedal or shift lever for the driver to operate — the computer controls the clutch disks as well as the actual shifting. The computer is able to shift gears in 0.2 seconds. It would be almost impossible for all of the torque available from the W-16 engine to flow out to just two wheels without constant wheel-spin. Therefore, the Veyron has full-time all-wheel drive. By applying the engine’s power to all four wheels through a computer-controlled traction-control system, the car is able to harness all of the engine’s horsepower, even at full acceleration.
Body Design
According to one of the Veyron’s designers, the biggest challenge in creating the Veyron was the aerodynamics. 
How do you keep a 250-mph passenger car on the road?
An F-1 car or a Champ car can travel at 250 mph or more, but they have a uniquely designed body, a single driver lying in a reclining position, just an inch or so of ground clearance and an aero-package made up of large wings to generate massive downforce. The Bugatti, on the other hand, is trying to look like a normal car and seat two passengers. The Veyron’s dimensions help to some extent. The car is 79 inches (200 cm) wide, 176 inches (447 cm) long and only 48 inches (122 cm) high. Keep in mind that a Hummer 2 is 81.2 inches wide. The Bugatti is extremely wide for its height. The underside of the Veyron, like an F-1 car, is streamlined and venturi-shaped to increase downforce. There is also a wing in the back of the Veyron (see below) that extends automatically at high speed to increase downforce and keep the car glued to the road. According to Popular Science: Hypercar, “With the moving tail spoiler we’ve got enough downforce now, about 100 kg (221 pounds) at the rear and 80 kg (177 pounds) at the front at top speed.”
The Veyron uses two snorkel-like devices one on either side of the engine to manage airflow. The Veyron has three reasons for managing airflow:
- At maximum power, the engine is consuming 45,000 liters of air per minute.
- At maximum power, the engine is burning 1.33 gallons of gasoline per minute and needs to dissipate all of that heat through its radiators.
- When stopping, the brakes need to dissipate heat ?- especially important when rapidly accelerating and braking on twisty road courses.
The engine of the Veryon sits behind the driver, so roof-mounted snorkels, the rear-deck vents and side-mounted scoops bring air to the engine and rear brakes.
The size of the engine and transmission, along with the four-wheel-drive system and the four drive shafts, along with the opulence of the passenger compartment (discussed in the next section) and the car’s oversized dimensions, all add weight. Even though the body is sculpted in carbon fiber to minimize its mass, the car weighs in at about 4,300 pounds (1,950 kg). For comparison, a Dodge Viper weighs about 1,000 pounds (454 kg) less.
Tires and Interior
Even the tires for the Veyron are unique. They’re specially designed by Michelin to handle the stress of driving at 250 mph. The tires need to be sticky like a race car’s and able to handle 1.3 G’s on the skidpad. However, they also need to last longer than the 70 or so miles of a typical race tire.
Michelin therefore created completely new tires to handle the Veyron’s unique requirements. In the rear, the tires are 14.4 inches (36.6 cm) wide. Specifically, the tires measure 245/690 R 520 A front and 365/710 R 540 A rear, where 245 and 365 are the width in millimeters (9.5 and 14.4 inches respectively). The rims are 520 mm and 540 mm in diameter (approximately 20 inches). These tires, in other words, are massive — the rears are the widest ever produced for a passenger car.
The tires use the Michelin PAX system. Their pressure is monitored automatically, and they can run flat for approximately 125 miles (201 km) at 50 mph (80 kph). According to Michelin, the run-flat detection system “plays an integral role in active safety in PAX System. Its role is to inform you of a loss of pressure, either gradual or sudden.” Once warned of an air leak by the PAX system, you can reduce your speed and head toward a tire repair center.
One advantage of the PAX system and its run-flat ability is that it eliminates the need for a spare tire.
The Interior
The Veyron seats two in lavish style. The interior is swathed almost completely in leather — the dash, seats, floor and sides are all leather. Only the instruments and a few metal trim pieces interrupt the leather experience.
The car also surrounds its occupants with every sort of electronic nicety, including a remarkable stereo system, navigation system, etc.
Is all of this worth a million bucks? Who knows. But regardless, the Veyron represents a remarkable technological achievement.
The Veyron is also likely to represent the far end of the automotive performance spectrum for some time to come. To create a car much faster will require adding even more weight, and delivering even more power to the wheels. The added weight means diminishing returns in the power-to-weight domain. Additional power means more wheelspin.
Look at a Champ car and consider how radical its appearance is compared to a passenger car. Consider also that a Champ car does not go much faster than the Veyron. The Veyron probably approaches the outer limits of the passenger car envelope, and we are unlikely to see much beyond the Veyron in terms of performance.
This is, in other words, as good as it gets.
Well, here is a video of how fast the Veyron can actually fly.
References: http://en.wikipedia.org/wiki/Bugatti_Veyron
http://auto.howstuffworks.com/bugatti.htm
