September 12, 2005
Source: Audi AG
The new Audi RS 4 from quattro GmbH breaks new ground in every respect, impressively demonstrating the leading-edge engineering embodied in the “Vorsprung durch Technik” slogan. The saloon features numerous innovations, delivering top performance whether on the road or on the track. This latest model developed by Audi subsidiary quattro GmbH combines motorsport technology with a high standard of practical value for everyday use. In creating this car, Audi’s development engineers have succeeded in placing a sporty all-round concept on the road which is capable of thrilling its driver in every situation, whether in everyday motoring or on the race track.
The Audi RS 4 continues the tradition of quattro GmbH in bridging the gap between motorsport and everyday motoring. It is a car which combines emotion and functional perfection, meeting all the demands made by the driver of a high-performance car in general and an Audi in particular in today’s motoring world.
At Audi, the “RS” abbreviation stands for unmatched performance, technological innovation and unique driving dynamics. To quote just two examples, the 420 bhp eight-cylinder engine is Audi’s first high-revving power unit, and also features its innovative FSI technology. A further forte of this exceptional V8 is its extremely compact size. The RS 4 for the first time features the latest generation of the permanent four-wheel drive system with asymmetric/dynamic torque distribution, under normal driving circumstances transferring 40 percent of the power to the front wheels and 60 percent to the rear. It is particularly well suited to a sport car of the calibre of the RS 4.
With each and every component of the new car being checked for minimum weight, the result of the consistent weight reduction process is a power-to-weight ratio of 3.93 kg per bhp.
The RS 4 is a truly unique, intelligent vehicle concept with superior drive train qualities, offering driving dynamics unmatched by any other car in its segment.
Engine: FSI delivers even better power and performance
The engine is key to the quality of any sports car. In the new RS 4, quattro GmbH has placed its trust in a compact V8 unit featuring petrol direct injection. In the 420 bhp high-revving eight-cylinder engine, FSI technology has reached a new highpoint. In this top product of what is a still young yet already highly successful technology, the petrol is injected directly into the combustion chamber, resulting in a uniform fuel/air mixture. Thanks to the cooling effect of the directly injected fuel, Audi’s development engineers have at the same time been able to increase the engine’s compression ratio.
The result is an even more efficient combustion process and, consequently, an even higher power output. This is demonstrated most clearly in the engine’s more spontaneous responsiveness. Thanks to this technically highly sophisticated injection method, optimum power output is produced in every driving situation.
FSI technology is already deployed in the world’s most successful racing car, the Audi R8, winner of the legendary Le Mans 24 Hours race no less than four times in the last five years alone (to mention just some of the car’s outstanding achievements). The figures illustrate the outstanding potential of the eight-cylinder unit. At 7,800 rpm the 4.2 litre engine delivers 420 bhp of power output. Peak torque is 430 Newtonmetres at 5,500 rpm. And no less than 90 per cent of this maximum torque is maintained consistently throughout a wide range of engine speed from 2,250 all the way to 7,600 rpm. Performance on the road is naturally equally impressive: the RS 4 accelerates to 100 km/h in 4.8 seconds and reaches 200 km/h in 16.6 seconds. At 250 km/h the vehicle’s speed is smoothly limited by an electronic control system.
The principle of the high-revving engine
Audi has deployed the high-revving engine principle for the first time in the RS 4. The maximum engine speed is 8,250 rpm. The significant advantages of this principle are superior power output at high engine speeds and a smooth, eager responsiveness all across the revs range. Further fortes are the car’s outstanding agility and fast-revving response as well as the kind of racing-style engine sound drivers of such cars expect. As a result of these qualities, the eight-cylinder power unit provides maximum thrust and performance in virtually all driving situations.
The ultra-compact V8
The V8 power unit is ultra-compact in its dimensions, fitting snugly into the engine compartment of the RS 4 without requiring any modifications to the body. The camshaft and ancillaries, with the exception of the alternator, are all driven by a chain for easy maintenance. An all-new development, features of the eight-cylinder unit powering the RS 4 include modified pistons and conrods, a new crankshaft together with its bearings, and new cylinder heads. A twin exhaust system with enlarged pipes provides even higher power output. These extensive measures enabled the 4,163 cc engine to break through the magical 100 bhp per litre barrier.
The car’s power-to-weight ratio is also impressive: 3.93 kg per bhp is a figure only the most thoroughbred sports cars were able to offer just a few years ago.
It goes without saying that the V8 featuring FSI technology complies with the Euro 4 emissions standard.