The modified V10, whose cylinder head covers are painted red, gives the Audi R8 GT breathtaking performance. The R8 GT sprints from a standing start to highway speed in 3.6 seconds, and from zero to 200 km/h (124.27 mph) in 10.8 seconds. And the thrust does not let up until the top speed of 320 km/h (198.84 mph) is reached.

Changes to the engine electronics coaxed an additional 26 kW from the ten-cylinder, which now produces 412 kW (560 hp) from a displacement of 5,204 cc. The torque curve peaks at 540 Nm (398.28 lb-ft) at 6,500 rpm, 10 Nm (7.38 lb-ft) more than in the production version. The V10 has a specific power output of 79.2 kW (107.6 hp) per liter displacement. Its power-to-weight ratio is 3.70 kilograms (8.16 lb) per kW or 2.72 kilograms (6.00 lb) per hp. The engine redlines at 8,700 rpm.

The long-stroke engine (bore x stroke 84.5 x 92.8 millimeters [3.33 x 3.65 in]), which is hand-built at the factory in Györ, Hungary, features a crankcase made of a aluminum-silicon alloy that is both lightweight and very strong. A bedplate – a frame for the crankshaft bearing bridges – further enhances its rigidity. The complete engine weighs only 258 kilograms (568.79 lb). It is characterized by a cylinder angle of 90 degrees and dry-sump lubrication, which uses a highly efficient oil pump module. Both solutions lower the center of gravity and thus improve driving dynamics.

The crankshaft is designed as a common pin shaft. The connecting rods of the opposing pistons engage a common crankpin, resulting in alternating firing intervals of 54 and 90 degrees. This unique rhythm gives the V10 its fascinating sound – a grand, technical music very much like that in racing. Two flaps in the exhaust system modulate its volume and tone as a function of load and engine speed.

The normally aspirated engine consumes an average of 13.7 liters of fuel per 100 km (17.17 US mpg) – very good fuel economy given the tremendous power. The FSI gasoline direct injection system injects the fuel into the combustion chambers at up to 120 bar of pressure. The turbulent mixture cools the cylinder walls, enabling a compression ratio of 12.5:1. A variable intake manifold and the continuous adjustment of the chain-driven camshafts ensure that the combustion chambers are fully filled. Flaps in the intake ports facilitate the formation of the mixture by inducing a tumbling motion in the inflowing air.

2011 Audi R8 GT Pictures

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