Based on the existing mid-engine R8 V10 and incorporating aerodynamic, weight-saving and mechanical developments used by the company's R8 LMS GT3 race car, Ingolstadt will build just 333 copies of the new 560-hp four-wheel-drive performance flagship.

Pricing has not yet been revealed, but given the extent of the changes to the new two-seater, buyers should expect a hefty premium over the R8 V10's $147,000 price tag when the GT goes on sale in North America. Audi of America has not yet confirmed U.S. plans, but the car is likely to appear here in spring 2011 as a 2011 model.

Although not originally planned to form part of the R8 lineup, Audi's decision to introduce the low-volume GT stems largely from customer requests for a more narrowly focused version of the mid-engine coupe, along the lines of the Porsche 911 GT3 RS--a car suitable for track days and club competition events but still legal for road use.

Key to the GT's increased performance is a series of detailed modifications that cut curb weight by 200 pounds to 3,362 pounds. It's still about 300 pounds heavier than the 911 GT3 RS and more than 400 pounds chunkier than the recently introduced Lamborghini Gallardo LP570-4 Superleggera, with which the R8 GT shares much of its driveline. However, Audi says a combination of weight reduction and increased power will provide the car with added straight-line speed and, in combination with modifications to its aluminum intensive chassis, sharper handling.

Among the changes aimed at slashing weight is a carbon-reinforced plastic liftback, fixed rear wing, modified brake calipers, reduction in sound-deadening material within the engine bay and a thinner windshield. Glass in the liftback has been replaced by polycarbonate.

At the heart of the R8 GT is a modified version of the R8 V10's naturally aspirated 5.2-liter direct-injection engine--essentially the same unit used by the Gallardo LP570-4 Superleggera, but with a different exhaust system. Distinguished by unique red cylinder heads, it has been tuned to deliver an additional 35 hp, and an extra 7 ft-lb of torque, to 398 lb-ft.

Power is channeled to the wheels via a beefed-up version of Audi's six-speed R-tronic manual gearbox and a viscous coupling that provides a nominal 15:85 front-to-rear apportioning of drive. When added front-end traction is required, the viscous coupling opens to provide a split of up to 30:70 front to rear. Audi also equipped the GT with a standard mechanical locking differential.

Audi says the R8 GT will hit 62 mph from standstill in just 3.6 seconds--0.3 second faster than the R8 V10 and 0.4 second quicker than the official time of the 911 GT3 RS. Top speed also extends by 2 mph to 199 mph, 6 mph faster than the 911 GT3 RS.

Along with the enhancements to the driveline, Audi reworked the R8's underpinnings, giving the GT firmer springs and dampers that lower it by 0.4 inch, and altered camber rates both front and rear for what Audi describes as "added agility." The stability control was recalibrated and gains a sport mode that delays the threshold of intervention, or the stability control can be switched off completely. Standard wheels are 19 inches, 8.5 inches wide in front and 11.0 inches wide at the rear, with standard 235/35 and 295/30 tires front and rear. Cup tires are an option.

Additional weight savings comes from carbon-ceramic brake rotors fitted with red anodized-aluminum six-piston calipers in front and four-piston calipers out back.

The R8 GT gets a series of subtle exterior styling upgrades aimed at increasing downforce, including a prominent splitter and a fixed rear wing, all made of carbon fiber. The chrome features are finished in matte gray. Four body-color schemes will be offered: Samoa orange, Suzuka gray metallic, ice silver metallic and phantom black pearl effect.

Inside, there are unique R8 GT instrument graphics, a special shift lever, a liberal splashing of Alcantara and unique door sills. As optional equipment, buyers can order the GT with a bolt-in roll cage, four-point belts, fire extinguisher and a kill switch for the battery.