The interior also harbored substantial weight-savings potential. The new, lightweight carpeting accounts for 7.9 kilograms (17.42 lb); the bucket seats with a chassis of glass-reinforced plastic (GRP) account for 31.5 kilograms (69.45 lb). Numerous additional detailed measures targeted the interior, the exterior and the technology, such as higher-grade, lighter steel for the exhaust system's tailpipes.
Even sharper and more effective: the design
The design of the Audi R8 GT is the expression of concentrated power – a beautiful, technical sculpture measuring 4.43 meters (14.53 ft) long, 1.93 meters (6.33 ft) wide and only 1.24 meters (4.04 ft) high. The exterior underwent numerous modifications that further sharpened the appearance. Many of them also reduce the weight and enhance the aerodynamics. The R8 GT produces even more downforce when driven fast than the production model – without any increase in the Cd value (0.36) or frontal area (1.99 m2) (21.42 sq ft).
The frame of the single-frame grille, its struts and the slats in the air intakes are finished in matt titanium gray; the grille is painted matt black. The splitter under the bumper has a double lip and is made of carbon. Slender, curved flics at the corners of the nose increase the downforce on the front axle and are also made of a carbon fiber composite.
One highlight of the R8 GT are the standard LED headlights, which use light-emitting diodes for all functions. They produce bright, homogeneous light, have a long service life and low energy consumption. The headlights also have an attractive and distinctive appearance. The daytime running lights each comprise 24 LEDs and appear as a continuous band. The reflectors are reminiscent of open mussel shells.
The defining element of the side view are the sideblades, which direct air to the engine and in the R8 GT are also made of matte carbon. The same material is used for the reduced-size housing of the side mirrors, which are mounted on an aluminum base. The 19-inch wheels feature an exclusive five twin-spoke Y design in a titanium-look finish. The front fenders sport "GT" badges.
The modifications to the rear of the car are particularly apparent, beginning with the fixed wing of matte carbon. The ventilation louvers on both sides of the rear hatch and the CFRP bumper, which integrates the large, round tailpipes and vents for the wheel wells, have been redesigned. The larger diffuser is made of carbon fiber composite; the license plate bezel and the wide slats at the rear are in matte titanium gray. The tail lights, which also use LED technology, have dark housings with panes of clear glass.
Audi offers the R8 GT in a choice of four body colors: Samoa Orange metallic, Suzuka Gray metallic, Ice Silver metallic and Phantom Black pearl effect.
Breathtakingly powerful: the 412 kW (560 hp) 5.2 FSI
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.
The drivetrain: uncompromising traction
Gear changes in the R8 GT are handled by the R tronic sequential manual transmission. The electrohydraulic clutch and switching unit receive their commands electronically. It changes its six gears much faster than a skilled driver could – within a tenth of a second at high load and engine speed.
The electronic management system offers an automatic mode with the Sport and Normal characteristics, and two manual levels. It is controlled using the short gear selector lever on the center tunnel and two paddles on the steering wheel. Maximum thrust when starting is ensured by Launch Control – a program that manages full acceleration with high engine speed and minimum wheel slip when starting.
quattro permanent all-wheel drive is the ideal technology for a high-performance sports car. The central viscous coupling located at the front differential sends 15 percent of the power to the front axle and 85 percent to the rear axle during normal driving. This split harmonizes perfectly with the Audi R8 GT's 43:57 percent weight distribution. The coupling sends as much as 30 percent of the power to the front wheels within milliseconds, if necessary. A mechanical locking differential at the rear axle further improves traction. It provides up to 25 percent lockup when accelerating and up to 40 percent on the overrun.
Chassis even tauter and more precise
The Audi R8 GT high-performance sports car is a driving machine with breathtaking lateral acceleration and lightning-fast, nearly instantaneous reactions. Its engine is mid-mounted close to the vertical axis; its mass is almost negligible during fast direction changes. The R8 GT is dynamic, precise and stable in almost every situation.
The chassis follows the classic racing design – double wishbones made of aluminum locate the wheels. The hydraulic, power-assisted rack-and-pinion steering has a direct 16.3:1 ratio and connects the driver closely and precisely with the road. A manually adjustable coilover suspension, which lowers the body by as much as 10 millimeters (0.39 in), is standard. Higher front and rear wheel camber rates make the handling a tick more agile than with the standard model.
The 19-inch forged wheels are 8.5 J x 19 up front and 11 J x 19 at the rear, and are shod with size 235/35 and 295/30 tires, respectively. Audi will mount 305/30 tires together with optional wheels on the rear axle upon request. Cup tires, which offer the ultimate in performance on dry roads, are available for racing enthusiasts.
Audi mounts internally ventilated, carbon fiber ceramic brake disks standard. They are extremely durable and abrasion-resistant as well as particularly lightweight. Together they weigh nine kilograms (19.84 lb) less than their steel counterparts of the same size. They measure 380 millimeters (14.96 in) in diameter up front and 356 millimeters (14.02 in) at the rear. The friction rings are bolted to the stainless steel caps via elastic elements. Red anodized aluminum brake calipers – with six pistons up front – are exclusive to the R8 GT.
The ESP stabilization program has been specially tuned to the R8 GT and can be switched into a Sport mode at the push of a button to allow spectacular, but safe, oversteer when accelerating out of a corner. The driver can deactivate the system entirely for a trip to the race track.
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Originally Posted by Ferrer
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