The R8 5.2 FSI quattro is a winner – its genes contain the cumulative experience of eight Le Mans triumphs and many other victories achieved by Audi over the past nine years. And the new top-of-the-line version retains these close links to motorsport: Starting in spring, its ten-cylinder engine in virtually unchanged form will display its potential on the racetrack – in the new R8 LMS racing car, which Audi is readying for the customer sports segment in accordance with the GT3 rules.
The V10, which is to a large extent a new development, exploits a total displacement of 5,204 cc and is designed to rev up easily. At 6,500 rpm it delivers 530 Nm (390.91 lb-ft) of torque and at 8,000 rpm it puts out 386 kW (525 hp). Its limit isn’t reached until 8,700 rpm – when each piston travels 26.9 meters (88 ft) per second. The specific power output is 100.9 hp per liter of displacement. And every hp only needs to propel 3.09 kilograms (6.81 lb) of weight, because the high-performance sports car in the version with the manual transmission only weighs 1,620 kilograms (3,571 lb).
0 – 200 km/h: 12.0 seconds
The Audi R8 5.2 FSI quattro provides superior performance. It rockets from zero to 100 km/h (62.14 mph) in 3.9 seconds. In the version with the sequentially shifting R tronic it passes the 200 km/h (124.27 mph) mark in another 8.1 seconds. And its powerful propulsion continues well beyond that, to a top speed of 316 km/h (196.35 mph).
The immense power, the eager response to the gas pedal, the outstanding revving ability, the palpable force of acceleration, and the thrilling sound – all these impressions combine to give a truly thrilling sports car experience. The V10 is a highly sonorous engine with growling bass tones and powerful high notes, which grows into a spectacular fortissimo as the engine revs up. Two sound baffles in the exhaust system that are controlled by underpressure modulate its volume and pitch as a function of the load and the engine speed.
The ten-cylinder layout is the ideal solution for maximum dynamism. Compared to a V8 with the same displacement, a V10 has smaller and lighter pistons and connecting rods, which makes it a free-revving engine. Compared to a V12, on the other hand, it has fewer components, resulting in lower moving masses and less internal friction. And it is very compact – even with all attached components the 10-cylinder engine is only 646 millimeters (25 in) long, 737 millimeters (29 in) wide and 696 millimeters (27 in) high.
V-angle of 90 degrees for a low center of gravity
The V10 is a member of the Audi family of V-engines with a 90 degree cylinder angle. This large cylinder angle results in a low center of gravity. The banks face each other with an offset of 18.5 millimeters (0.73 in), the bore is 84.5 millimeters (3.3 in), the stroke 92.8 millimeters (3.6 in). To achieve maximum rigidity with minimum weight, the crankshaft was designed as a common-pin shaft, which results in alternating ignition distances of 54° and 90°. This ignition sequence is one of the reasons for the racing-like sound of the V10 engine.
The crank case is produced by a low-pressure diecasting method of a hypereutectic aluminum-silicon alloy – a high-tech material that combines low weight with high strength. The high silicon content of this alloy endows the cylinder tracks with the required wear resistance to withstand the very high average piston velocity of up to 26.9 m/s. The entire engine weighs only 258 kilograms (569 lb), just 31 kilograms (68 lb) more than the V8.
The bedplate design – the lower bearing brackets for the crankshaft are integrated into a single frame – provides the crankcase with maximum rigidity and optimum vibration behavior. Integrally cast iron bearing brackets reduce the thermal expansion of the aluminum housing and minimize the play in the main crankshaft bearings. The forged crankshaft and the forged-steel con rods combine high strength with low weight. The pistons are forged of a high-strength aluminum alloy.
The V10 obtains its oil, which is temperature-controlled by dual coolers, from a dry sump – a design that allows the engine to be installed very low. The external container and the oil pump module, which is designed to work very efficiently with several suction levels and pressure levels, ensure lubrication under any conditions – even during the extreme transverse acceleration exceeding 1.2 g of which the R8 5.2 FSI quattro is capable.
The camshafts, as well as the oil pump, the water pump and parts of the accessory subsystems, are powered by maintenance-free chains located on the rear wall of the engine. All four camshafts are adjustable through 42 degrees crank angle, which provides a wide range of control times for the 40 valves, which are actuated by roller-mounted cam followers. The exhaust valves are subject to a high thermal load and are lined with sodium to assist in cooling.
High Cylinder Filling and Perfect Mixture Formation
The induction pipe is made of lightweight plastic and designed for optimized flow conditions through the ports. Integrated in the intake ports are tumble flaps that are controlled by the engine management system. During low-load conditions, these tumble flaps stroke the inducted air inward to impart motion to it, which improves the efficiency of the combustion process. At full load, the tumble flaps adapt their shape to the contour of the intake ports to optimize the flow.
On the exhaust side, the dynamics of the gas exchange are supported by individual elbow joints. They are precisely attuned to the operation of the ten-cylinder engine.
The ten-cylinder engine uses direct injection as per the FSI principle developed by Audi. In the Audi R8 racing car it has impressively demonstrated its superiority in five overall victories in the Le Mans 24 Hours. A common rail system injects the fuel with up to 120 bar of pressure into the combustion chambers through valves placed laterally on the cylinder. This injection strategy causes internal cooling and consequently allows a very high compression ratio of 12.5:1. It contributes both to the high power output and to high efficiency. The engine gets by on an average 13.7 liters of fuel per 100 kilometers (17.17 US mpg).
The V10 is managed by a highly advanced control system that employs two computers in a master-slave arrangement.
The equipment, specifications and prices stated herein refer to the model line offered for sale in Germany. Subject to change without notice; errors and omissions excepted.