Reduced Weight Makes Super-Performing Audi R8 GT

Since it introduced the first R8, Audi has made waves not just in supercar circles, but also in racing where the R8 LMS won 23 races in its first season.

Capitalizing on that progress, the new Audi R8 GT is a higher performance version of the R8 V-10 with the power output increased to 560 bhp, and the weight reduced by 220 lb (100 kg).

Sounds good, except that despite its aluminum frame, the Audi R8 is not that light at 3,583 lb (1,625 kg). Audi is producing a limited run of 333 R8 GTS.

Lighter, but not very light

True, the car does have Audi's quattro four-wheel drive system, which increases the weight, but this is about 500 lb (227 kg) more than the Lamborghini Gallardo LP 570-4, which also has four-wheel drive and an aluminum frame.

Nevertheless, the Audi R8 GT is an extremely fast car, accelerating to 60 mph in 3.3 seconds, which is extremely quick, and can reach 198 mph (320 km/h).

Extra 35 bhp, and a bit more torque

The power output has been increased by 35 bhp to 560 bhp at 8,500 rpm, while maximum torque has gone up from 390 lb ft (530 Nm) to 398 lb ft (540 Nm) @ 6,500 rpm, the increase being more significant at the top end than in mid-range power, which is what you would expect. The power output is just 10 bhp less than in the Lambo, and results from changes to the engine management system.

The engine is, of course, basically the same as that used by Lamborghini, but it is produced in the Audi plant in Hungary. This latest version has direction injection, variable valve timing and variable-length intake manifolds to combine good top end power with reasonable low-speed torque and smooth running at low speeds. It is a dry-sump unit, which helps keep the center of gravity low.

Viscous coupling center differential

In the R8 GT, the quattro four-wheel drive system is controlled by a viscous coupling center differential, which is actually mounted at the front axle, to help give the front:rear weight distribution of 47:53, pretty near ideal. 

Normally, only 15% of torque goes to the front axle, with 85% to the rear, which ensures sporty handling. If tire slip occurs at the front, up to 30% of torque can be sent there in an instant. There is a mechanical limited slip differential, which allows up to 25% slip on drive, and 40% on over-run, at the rear.

The 19-inch forged wheels are 8.5-inch section at the front and 11-inch at the rear, and are shod with 235/35 and 295/30 tires, respectively, and owing to the wider rear tires, the car is slightly wider than the other R8s. Buried in the wheels are the carbon-ceramic brake discs. At the front, these are 15-inch (380 mm) diameter, and at the rear they are 14-inch (356 mm) diameter.

To reduce weight by 220 lb, the Audi engineers made changes to many components, from the brakes through the body to the battery. Here are a few changes:

• Battery, 21 lb (9 kg) lighter;
• Seats, 70 lb (32 kg) lighter;
• Carpet, 17 lb (8 kg) lighter;
• Rear hatch above the engine, 15 lb (7 kg);
• Rear bumper, 11 lb (5 kg) lighter.

As on other R8s, there is a stability control, and this one has a sport mode, and can be turned off for racing. Also, there is a Racing Pack for customers who want to race the Audi R8 GT.