This is gonna be one heck of a ride!
The new Audi RS4
The Audi RS 4 – The Sports Car for 365 Days a Year
Taking a new approach, once again clearly proving Audi’s “Vorsprung durch Technik”: quattro GmbH’s new Audi RS 4. An outstanding new saloon boasting numerous innovations for absolute superiority on both road and track. This latest model developed by Audi subsidiary quattro GmbH combines motor sport technology with a high standard of practical value for everyday use. In creating this car, Audi's engineers have succeeded in placing an intelligent all-round concept on the road able to thrill its driver in every situation, whether on the race track or in the big boulevards of the world.
The Audi RS 4 continues the tradition of quattro GmbH in bridging the gap between motorsport and everyday motoring. It is a car which brings together strong emotions and perfect function in an ideal synthesis of both worlds, a car which meets all the demands made by the driver of a premium saloon in general and of the most outstanding Audi in particular in the world of motoring today.
At Audi, the “RS” abbreviation stands for ultimate performance of the highest calibre, supreme technological innovation and truly unique driving dynamics. To quote just two examples, the 420 bhp eight-cylinder is Audi’s first high-speed power unit, and it comes with Audi’s highly innovative FSI technology. A further forte of this exceptional V8 is its extremely compact dimensions. The RS 4 is also the first car to feature Audi’s new generation of permanent four-wheel drive with asymmetric/dynamic distribution of torque, a concept particularly suitable for a sports car of the calibre of the RS 4.
And 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 horsepower.
The RS 4 is a truly unique, intelligent car concept with superior drivetrain qualities offering driving dynamics of a standard not to be found anywhere else in this segment.
Power Unit
FSI for even better power and performance
The engine is crucial to the power and performance of every sports car – which is precisely why quattro GmbH features a compact V8 with direct gaso¬line injection in the new RS 4. Indeed, FSI fuel injection technology now reaches a new level of perfection in this 420 bhp high-speed eight-cylinder, gasoline being injected directly into the combustion chambers of this top-end product boasting a young but already extremely successful technology, creating an absolutely smooth, balanced, and consistent fuel/air mixture in the process. And 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 effective combustion process and an even better power yield all in one. This is borne out in particular by the engine’s even greater responsiveness, the elaborate fuel injection technology further optimising the development of power and performance in every situation on the road.
Audi’s FSI technology is already to be admired in the world’s most successful racing car, the Audi R 8 bringing home victory in the legendary 24 Hours of Le Mans no less than four times in the last five years alone (to mention just some of the car’s outstanding achievements).
Clear facts and figures prove the impressive potential of this outstanding eight-cylinder: maximum output of the 4.2-litre power unit is 420 bhp. Peak torque is 430 Newton-metres at 5500 rpm. And no less than 90 per cent of this maximum torque is maintained consistently throughout a wide range of engine speed from 2250 all the way to 7600 rpm. Performance on the road is naturally equally impressive, the RS 4 accelerating to 100 km/h in 4.8 seconds and reaching 200 km/h in 16.6 seconds. The ongoing surge of power and performance is then gently cut off by electronic control at 250 km/h.
The high-speed engine principle
The RS 4 is Audi’s first car to feature the high-speed engine principle, the power unit reaching speeds of up to 8250 rpm. The significant advantages of this principle are superior power at high engine speeds, consistent and smooth development of power and performance, as well as superior responsiveness throughout the entire speed range. Further fortes are the car’s outstanding agility and fast-revving response as well as an engine sound reminiscent of motorsport ¬ the sound that the driver of such a car simply expects. 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 changes to the body of the car. The camshafts and ancillary units, with the exception of the alternator, are all driven by a chain for easy maintenance. An all-new development, the eight-cylinder powering the RS 4 comes, inter alia, with modified pistons and connecting rods, as well as a new crankshaft together with its bearings and new cylinder heads. A double-chamber exhaust system with extra-large pipe cross-sections helps to boost engine output and performance to an even higher level, these significant improvements all adding up at the end of the day to give this 4163 cc power machine an output per litre beyond the magical 100 bhp limit.
The car’s power-to-weight ratio is equally impressive: 3.93 kg per horsepower is a figure only the most thoroughbred sports cars were able to offer just a few years ago.
It almost goes without saying that the V8 featuring FSI fuel injection technology complies in full with the Euro 4 emission standard.
Drivetrain
New generation of quattro drive
Getting all this power on to the road was of course a significant challenge. And to successfully meet this challenge, Audi – naturally – focuses on quattro permanent four-wheel drive, where 25 years of experience and superior market leadership in the four-wheel-drive passenger car segment give the customer significant benefits. Now, the RS 4 features a new generation of quattro drive with asymmetric/dynamic distribution of engine power and torque.
The Torsen power divider delivers the output and torque of the engine individually to the front and rear axle as required, thus ensuring optimum traction at all times: reflecting even minor changes in road conditions, the flow of power is re-directed immediately as a function of torque, with up to 100 per cent of engine power and torque going to just one axle whenever appropriate. This new distribution of drive power makes the Audi RS 4 an even more dynamic performer on the road. Apart from traction, ease of control, stability, load change and transient behaviour, the car’s agility and steering behaviour in particular have been significantly improved once again, clearly underlining the very sporty performance and character of the RS 4.
The term “Torsen” comes from “torque” and “sense”, which, taken together, quite literally means “sensing the development and build-up of torque”. The Torsen differential is a self-locking worm gear system building up its locking action only under power, while allowing differences in speed both when applying the brakes and in bends.
Ensuring very short gearshift travel, the six-speed gearbox combines compact dimensions with low weight and a high standard of shift comfort. Adapted to the power unit of the RS 4, the individual gear increments provide excellent power yield in practice, conveying the output of the engine to the drive wheels of the car with maximum efficiency.
Chassis and Suspension
Superior at all times
Even the best drivetrain is nothing without the right chassis and suspension.
Which is precisely why quattro GmbH consistently uses the benefits of quattro drive and a supreme engine on the Audi RS 4: The sports suspension featured as standard serves to reliably convey the superior power of the engine on to the road appropriately at all times.
This superiority is ensured on Audi’s new sports saloon by high-performance aluminium suspension with a four-arm front axle and trapezoid-arm rear axle. Precise steering behaviour, sensitive feedback from the steering, sporting agility, and excellent directional stability make the RS 4 the perfect car both for the race track and for the motorway and country road.
Each wheel on the front axle runs on four aluminium track control arms. The trapezoid-arm rear axle, in turn, offers an equally outstanding, first-class potential in driving dynamics, the torsionally and flexurally stiff trapezoid arm taking up most of the forces acting on the wheels. Together with the track arm further to the rear, this special configuration defines the elastokinematic behaviour of the rear axle with ultimate precision.
Dynamic Ride Control
The Audi RS 4 comes with Audi’s DRC Dynamic Ride Control featured for the first time in the Audi RS 6. DRC serves to reduce both body roll and dive along the car’s longitudinally and lateral axes.
This dynamic body control is ensured by the specific flow of oil between the damp¬ers in diagonal arrangement, largely eliminating any movement of the body when setting off (squat effect) and preventing both body dive when applying the brakes and body roll in fast bends. The result, clearly, is an even higher standard of driving dynamics in the RS 4.
DRC has already won over many enthusiasts in the RS 6. And now, introducing the system in the RS 4, quattro GmbH has succeeded in making DRC Dynamic Ride Control even more compact and lighter, the system now not even requiring an electronic control unit. Instead, the individual suspension dampers are connected hydraulically to one another by a central valve, adjusting instantaneously to every driving situation on the road.
The combination of quattro drive, DRC, and the suspension specifically geared to the RS 4 allows this outstanding high-performance Audi to quite literally “run on rails” even at the highest speeds in bends, thus maintaining its superior performance when other drive concepts have long reached their limits. And it almost goes without saying that the Audi RS 4 features the latest generation of ESP stability control designed and configured especially for this car.
18-inch wheels featured as standard
The new Audi RS 4 comes as standard on 18-inch wheels boasting 255/40 tyres. 19-inch wheels are available as an option. Focusing carefully on the RS 4, Audi’s designers have created both light and at¬tractive cast aluminium wheels in five-arm design, a special production process ensuring enhanced stiffness and lower weight on even thinner walls. The 19-inch wheels come on 255/35 19 tyres, and are also available as an option with special Pirelli P Zero Corsa sports tyres made specifically for racing but also suitable for road use. Compared with the “normal” A4, the RS 4 is lowered throughout by 30 millimetres. A further important change is the wider track, up by 37 millimetres at the front and 47 millimetres at the rear. Both the springs and dampers have of course also been adapted to the superior potential of the RS 4 in their dimensions.
The servotronic power steering has likewise been modified to meet the particular requirements of Audi’s new sports saloon, responding directly to the driver’s commands and ensuring short, crisp steering travel most appropriate for the RS 4.
Brakes for the race track
The RS 4 also offers truly outstanding deceleration and stopping power ensured by the 18-inch brake system. Cross-drilled and inner-vented, the brake discs measure 365 millimetres in diameter up front and 324 millimetres or 12.8” in diameter at the rear. They come in floating arrangement, meaning that the cast-iron friction ring on the brake system is bolted on to the aluminium brake disc cover. The result is a significant improvement of the brakes’ resistance to fading, particularly under extreme loads, that is at high operating temperatures. This serves to prevent the so-called “bulging” effect, with the brake discs bulging out and the brake pads no longer coming to rest perfectly on the discs. A further positive side-effect of this technology is the reduction of unsprung masses in the interest of enhanced driving dynamics, which almost completely eliminates any distortion or adverse tension in the materials used.
A further advantage is the optimisation of brake venting geometry by means of Naca jets keeping the brake discs appropriately cool at all times.
Featuring custom-made RS eight-piston fixed callipers on the front wheels (four pis¬tons and two brake pads on the inside and outside of each brake disc) as well as single-piston swing callipers on the rear wheels, the Audi RS 4 offers supreme stop¬ping power and directional stability. The ESP 8.0 stabilisation program, electronic brake-force distribution EBD, and the ABS anti-lock brakes have all been tailored to the specific dimensions of the brake system.
An additional safety feature offered by ESP is the dry braking function: In bad and wet weather the system regularly applies the brake pads to the discs in a pro¬cess virtually unnoticeable to the driver, thus removing water from the brake discs in the interest of enhanced stopping power. Further features included in the ESP stability program are the electronic differential lock, anti-spin control, and the ABS anti-lock brakes.
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