Immense power, eager response and powerful acceleration, extraordinarily free-revving and a rousing sound – the R8 Spyder delivers a skin-tingling sports car experience. At idle and when coasting, its 5.2 liter V10 plays a characteristic Audi song – a throaty roar. Growling bass sounds and jubilant trumpets join in as engine speed increases, rising in concert to a crescendo, to a fortissimo.
The V10, which has a displacement of 5,204 cc, has the character of a racing engine. No wonder: With minimal modifications, the engine also powers the GT3 race car, which is based on the closed R8. Its peak torque of 530 Nm (390.91 lb-ft) is available at 6,500 rpm; rated engine speed is 8,000 rpm, where it produces 386 kW (525 hp). The electronic rev limiter does not intervene until 8,700 rpm, when the pistons travel 26.91 meters (88.29 ft) every second.
0 to 60 mph in 4.1 seconds; 0 to 125 mph in 12.7 seconds, top speed of 194 mph
The ten-cylinder has a specific power output of 100.9 hp per liter displacement. Each hp only has to move 3.28 kilograms (7.23 lb) of weight. Equipped with a manual transmission, the open-top high-performance sports car from Audi tips the scales at only 1,720 kilograms (3,791.95 lb). Performance is breathtaking. The Audi R8 Spyder 5.2 FSI quattro launches from a standing start to 100 km/h (62.14 mph) in 4.1 seconds. The version with the R tronic sequential transmission needs only an additional 8.3 seconds to break the 200 km/h (124.27 mph) mark. And the acceleration just keeps coming up to a top speed of 313 km/h (194.49 mph).
Ten cylinders: maximum dynamics
Ten cylinders are the ideal configuration for maximum dynamics. Compared to a V8 with the same displacement, a V10 has smaller and lighter pistons and connecting rods, allowing it to rev easier and higher. Compared to a V12, on the other hand, it has fewer components, which keeps the moving masses and thus internal friction low. The V10 is extremely compact – including all bolt-on parts, it measures only 646 millimeters (25.43 in) long, 737 millimeters (29.02 in) wide and 696 millimeters (27.40 in) tall. Like nearly all V engines from Audi, the ten-cylinder – built by hand at the plant in Györ, Hungary – has a 90 degree cylinder angle. This wide opening results in a low center of gravity. The two opposing banks are offset by 18.5 millimeters (0.73 in). The bore measures 84.5 millimeters (3.33 in) and the stroke 92.8 millimeters (3.65 in). The forged steel crankshaft is configured as a common pin shaft – each set of two opposing connecting rods engage the same crankpin. This design combines maximum rigidity with minimal weight, and ensures that the V10 alternately ignites in 54 and 90 degree intervals, which plays a major role in its goosebump-raising sound.
The crankcase is manufactured using low-pressure die casting, a complex method that ensures a particularly homogenous structure. Its aluminum-silicon alloy combines low weight with high strength. Its high silicon content makes the cylinder barrels extremely resistant to wear. The entire engine weights only 258 kilograms (568.79 lb). The crankcase is configured as a bedplate construction: The lower bearing bridges for the crankshaft are integrated into a common frame for maximum rigidity and optimal vibration behavior. Because they are made of cast iron, they reduce the thermal expansion of the case and thus keep the clearance at the main crankshaft bearings within tight tolerances. The forged crankshaft and the connecting rods of forged steel also combine high strength with low weight. The pistons are forged of a high-strength aluminum alloy.
Oil supply like in motorsport: dry sump lubrication
The V10 features dry sump lubrication – a design that enables a low installation position and a corresponding vehicle center of gravity. The external tank and oil pump, which works with five different suction and discharge phases in the interest of efficiency, ensures lubrication under any conditions. The pump is designed for lateral accelerations of 2 g, as occur in motorsport. It draws the motor oil separately from the crank space, the chain box and the cylinder heads, and two coolers reduce oil temperatures.
The camshafts, as well as the oil pump, water pump and several auxiliaries, are powered by maintenance-free chains located on the rear wall of the engine. All four camshafts can be moved through 42 degrees of crankshaft rotation. This allows for a wide timing range for the 40 valves, which are actuated via roller cam followers. The exhaust valves are sodium-filled, which ensures a better cooling effect.
The V10 is managed by a sophisticated engine management system that operates with two computers in a master-slave configuration. Its direct fuel injection system operates according to the FSI principle developed by Audi. It is the ideal solution for the road and for motorsport, where it has long proved its superiority: The Audi R8 racing car won the 24 Hours of Le Mans race in four of five starts with FSI power. A common rail system is responsible for distributing the mixture. It injects the fuel into the combustion chambers at up to 120 bar of pressure through nozzles located in the side of the cylinder head. The fuel mixture is swirled intensely and thus cools the walls. This enables a very high compression ratio of 12.5:1, which contributes to the high performance and very good efficiency. Mated to the R tronic, the ten-cylinder consumes an average of 13.9 liters of fuel per 100 km (16.92 US mpg). The 80 liter (21.13 US gallons) tank provides for a long cruising range.
The air induction path has been optimized for low losses. The intake manifold, which is made of a lightweight plastic, is characterized by its flow-optimized geometry. Tumble flaps controlled by the engine management system are integrated into the intake ports. At low load and engine speed, they cause the aspirated air to move with a roller-like motion (“tumble”), which further increases the efficiency of the combustion process. On the exhaust side, a low backpressure and a sophisticated manifold ensures gas exchange with maximum dynamics. Two vacuum-controlled sound flaps in the exhaust pipe modulate the volume and timbre of the V10 as a function of load and engine speed.
At only 215 millimeters (8.46 in) in diameter, the intermediate plate clutch in the R8 Spyder 5.2 FSI quattro is very compact, which is also necessitated by the low installation position of the engine. A six-speed manual transmission comes standard. The lever moves precisely and easily with short throws through a lavish, open stainless steel gate – typical Audi.
Audi also offers the R8 Spyder with an optional high-tech transmission – the sequential R tronic. With the short selector lever and the aluminum-look paddles on the steering wheel, it conveys an authentic racing feeling. Shift speeds vary as needed: The change of gears is comfortable during moderate driving; at higher engine loads and speeds, gear changes are completed within a tenth of a second. The driver’s commands are transmitted electrically. The gearshift unit has its own hydraulic fluid loop, which is pressurized to between 40 to 50 bar. The hydraulics manage the clutch and change the gears.
The R tronic is a versatile system, offering both a manual and a fully automatic operating mode. In both cases the driver can choose from two programs. The R tronic is most comfortable in the “Automatic Normal” mode, and offers the greatest dynamics in “Manual Sport” mode.
The standard launch control feature permits rocket-like starts. It is activated by a simple and exciting procedure: Select S mode, turn off the ASR anti-slip control, put the car in gear, step on the brake, floor the accelerator and wait until a constant engine speed is established. When the driver then releases the brakes, the launch control manages the engagement of the clutch within milliseconds, and the V10 delivers all of its power to the road with ideal tire slip. The Audi R8 is the only vehicle for which Audi offers this function with a manual transmission.
More grip: quattro permanent all-wheel drive
The extra bit of traction that allows the R8 Spyder 5.2 FSI quattro to pull away from its rivals is provided by the quattro permanent all-wheel drive – the superior technology for a high-performance sports car, in particular. Four powered wheels find more grip at the exit from a curve than two, enabling the driver to accelerate sooner again. Lateral dynamics and stability also benefit from quattro all-wheel drive. The R8 Spyder handles safely and reliably.
The mid-engine concept of the R8 model series necessitates a special layout for the quattro drivetrain. One drive shaft runs from the gearbox, which is mounted transversely behind the V10, through the engine to the front differential, where a viscous coupling distributes the power between the axles. In regular operation, it sends roughly 85 percent of the torque to the rear axle and can send up to 30 percent to the front within milliseconds, if necessary. A mechanical locking differential at the rear axle further improves traction. It provides a locking value of up to 25 percent when accelerating and up to 40 percent on the overrun.
The mid-engine concept is the ideal solution for the Audi R8 Spyder 5.2 FSI quattro high-performance sports car. It enables an axle load distribution ratio of 43:57 between the front and back, and packs the engine in the middle of the car, close to the vertical axis. This nearly eliminates the inertia of the engine mass during fast changes of direction. The fuel tank is located close to the engine, in the crash-protected area behind the seats. The amount of fuel has hardly any effect on axle load distribution.
The R8 Spyder 5.2 FSI quattro is an integrated system of speed and highly concentrated emotions embedded in perfect technical expertise. The high-performance sports car from Audi turns spontaneously, almost immediately, into corners and handles them with stoic aplomb, precisely guided by its responsive steering.
The limit is extremely high and is very easy to manage, and all four wheels claw back into the asphalt at an early stage when exiting the curve. The quattro all-wheel drive literally meshes the car with the road.
Yet the chassis is surprisingly comfortable over long distances. The double triangular wishbones at all four wheels – a classic principle in motorsport – are forged aluminum to reduce the unsprung masses. Rubber-metal bearings dissipate lateral forces into the body with carefully defined precision, while at the same time ensuring good longitudinal elasticity and filtering a majority of the undesired vibrations away from the road. The track measures 1.64 meters (5.38 ft) up front and 1.60 meters (5.25 ft) in the back.
The hydraulic rack-and-pinion power steering with its highly differentiated, sensitive feedback makes a major contribution to the feeling of uncompromising precision when driving the vehicle. It features a sporty and direct 16.3:1 ratio. Audi fine-tuned the chassis and its setup over 9,000 test kilometers in the toughest laboratory in the world – the North Loop of the Nürburgring race track.
Sophisticated damping: Audi magnetic ride
The R8 Spyder 5.2 FSI quattro comes standard with another high-end feature – Audi magnetic ride continuously adapts the function of the chassis to the profile of the road and the driver’s style. The controller, which receives signals from a sophisticated system of sensors, continuously computes the optimal values for each individual wheel. When the R8 Spyder steers into a curve, the damping force on the outermost wheel is increased, which reduces the tendency of the body to roll and the reaction becomes even more spontaneous. The driver can choose between two base characteristics – normal mode and sport mode.
A synthetic hydrocarbon oil containing tiny magnetic particles between 3 and 10 thousandths of a millimeter in diameter – one tenth the thickness of a human hair – circulates in the shock absorber pistons.
When a current is applied to a coil, a magnetic field is generated in which the particles realign so as to be perpendicular to the flow of the oil in the piston channels and thus prevent it from flowing through. This process is completed in just a few milliseconds, much faster than with conventional adaptive damping.
The R8 Spyder 5.2 FSI quattro rolls on 19-inch, forged alloy wheels with an attractive 10-spoke Y design. The tires measure 235/35 up front and 295/30 in the back, and a control function monitors the tire pressure. The Audi exclusive line includes wheels of the same size featuring a five-twin-spoke design and a titanium gray or high-gloss, polished surface.
Incredible performance: the brakes
Extreme power necessitates uncompromising stopping power – the R8 Spyder has a powerful brake system on board. Eight-piston aluminum brake calipers are mounted up front, with four-piston calipers mounted in the back.
To dissipate the heat as quickly as possible, the discs are internally ventilated and perforated. The discs measure 365 millimeters (14.37 in) in diameter at the front and 356 millimeters (14.02 in) at the rear. Each disk comprises a steel friction ring and an aluminum cap; the two components are connected by stainless steel pins to prevent the transfer of temperature peaks.
Audi will mount an exclusive technology upon request – perforated ceramic brake discs painted Anthracite Gray. On duty up front are six-piston monoblock calipers of aluminum and 380 millimeter (14.96 in) discs, with floating calipers and 356 millimeter (14.02 in) discs in the back. The calipers are painted Anthracite Gray and are bear the lettering “Audi Ceramic.” The ceramic disks are extremely lightweight, together weighing nine kilograms (19.84 lb) less than their steel counterparts. They can also easily handle the loads of more aggressive driving and are always free of corrosion.
The base material for the ceramic discs is silicon carbide, an extremely hard, abrasion-resistant material with a diamond-like crystal structure. Embedded in it are high-strength carbon fibers that absorb stresses. The complex geometry of the cooling ducts ensures that heat is rapidly dissipated. The friction ring is bolted to the stainless steel cap via ten elastic elements.
The Audi R8 Spyder 5.2 FSI quattro brakes with aplomb – strongly, precisely and stably. A specially configured stabilization system monitors the vehicles dynamic driving limits. At the touch of a button, the driver can activate a sport mode that permits spectacular but safe oversteer when the gas is applied while exiting a curve. The ESP together with the anti-slip control can also be completely deactivated for dynamic driving situations such as a trip to the race track. The hill-start assist, a sub-function of the system, makes it easier to start off on grades by maintaining the brake pressure for a brief period after the brake pedal is released.