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 motor sport 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 motor sport 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 sports 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 high point. This is where the experience gleaned in building the equally high-revving race engine from the Le Mans-winning Audi R8 has proved invaluable. The most successful racing car in the world, with which Audi has among other things captured the title in the legendary 24-hour race in four out of the past five years, likewise featured a V8 FSI as an efficient source of propulsion that took it that decisive extra lap.
In this top product of what is an innovative yet already incredibly 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. This further enhances the engine’s efficiency.
Petrol direct injection is in fact the very basis of a more effective combustion process and therefore of improved 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.
The figures illustrate the outstanding potential of the eight-cylinder unit. The V8 revs up to a speed of 8,250 rpm. The 4.2 litre engine already delivers 420 bhp of power output at 7,800 rpm. With its displacement of 4,163 cm3, this sports-car engine breaks through the magic barrier of 100 bhp per litre, a truly outstanding achievement for a production saloon. Peak torque is 430 Newton metres at 5,500 rpm.
And 90 per cent of this maximum torque is maintained consistently throughout an impressively wide engine speed range from 2,250 all the way to 7,600 rpm. The result is excellent pulling power at all times, enabling the driver to drive in a relaxed style without frequent gear changes.
Performance on the road is impressive, too: the RS 4 saloon accelerates to 100 km/h in 4.8 seconds; the RS 4 Avant follows just one-tenth of a second behind, and the Cabriolet likewise reaches the 100 km/h mark after just 4.9 seconds. The speedometer needle touches 200 km/h in 16.6 (Avant 16.9; Cabriolet 17.5) seconds. On all three versions, the speed is gently governed electronically when the needle reaches 250 km/h.
The high-revving principle
Audi has used the high-revving engine principle for the first time in the RS 4. The advantages of this principle are superior power output at high engine speeds, a smooth power flow and 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. The eight-cylinder engine provides maximum propulsion in virtually all driving situations and is equally appropriate for a relaxing driving style with minimum gearshifting and for exploits worthy of the racetrack.
It goes without saying that the free-revving V8 sports engine with FSI technology complies with the Euro 4 standard.
The ultra-compact V8
The V8 power unit is ultra-compact in design, fitting snugly into the engine compartment of the RS 4 without necessitating any modifications to the body. Furthermore, its weight is correspondingly low. The camshaft and ancillaries, with the exception of the alternator, are all driven by a chain for easy maintenance. An all-new development, the eight-cylinder unit powering the RS 4 includes such features as modified pistons and con rods, a new crankshaft together with its bearings, and new cylinder heads. A dual-branch exhaust system with enlarged pipes provides even higher power output.
The power-to-weight ratio is impressive: 3.93 kg per bhp is a figure that only the most thoroughbred sports cars were able to offer just a few years ago. The figure for the Avant is only slightly higher.
Drivetrain: New quattro generation
Getting all this power on to the road was of course a significant challenge. Audi’s answer is - of course - its quattro permanent four-wheel drive system. A quarter of a century’s experience and market leadership in the four-wheel-drive car segment represent genuine benefits for Audi’s customers. The RS 4 features a new generation of quattro drive with asymmetric/dynamic torque distribution.
A self-locking centre differential that operates without any additional sensors or actuating elements directs the power to the front and rear axles in line with demand. Indeed, the RS 4 still achieves surface grip when other drive concepts have long since come up against their limits. In variable road conditions the power can be immediately diverted depending on the level of torque achieved. The new distribution system, which under normal road conditions transmits 40 percent of the power to the front wheels and 60 percent to the rear, makes the Audi RS 4 an even more impressively dynamic drive. Alongside traction, controllability, stability, load reversal and transition response, aspects of agility and steering have also been substantially enhanced, underscoring the highly sporty character of the car.
And the RS 4, in common with all Audi quattro models, of course has four driven wheels in every situation, right up to top speed.
The centre differential is a self-locking worm gear that “senses” how much torque can be transferred. It operates purely mechanically according to the principle of force equals counterforce. If, for instance, the coefficient of friction at one pair of wheels falls, it is no longer possible to transfer as much torque (equivalent to force x lever arm). The internal structure of the centre differential means that the power flow is correspondingly diverted automatically to the other axle.
Thus the locking action is only prompted under the influence of the drivetrain. The transmission permits differences in operating speeds when braking and cornering, and equalises these.
The rear axle differential is fitted with additional cooling fins. This is Audi’s response to the high loads to which the RS 4 may be subjected.
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 gearing provides excellent power yield in practice, conveying the output of the engine to the driven wheels of the car with maximum efficiency.
Chassis: In full control at all times
The best drivetrain deserves a corresponding chassis. In the Audi RS 4, quattro GmbH has consistently applied all the benefits of quattro drive and the engine. The standard sports suspension with what is now a hallmark of the RS, the DRC system (Dynamic Ride Control), ensures that the engine’s power is translated appropriately into propulsion.
This superiority is ensured on Audi’s new sports saloon by high-performance aluminium suspension with a four-link front axle and a trapezoidal-link rear suspension. Precise steering, with sensitive feedback, sporty agility and excellent directional stability make the RS 4 the perfect car for both the motorway or country road, and for the racetrack.
Each wheel on the four-link front axle is guided by four aluminium transverse links. The trapezoidal-link rear suspension offers top-class driving dynamics. This torsion-proof and non-flexing trapezoidal link absorbs a large portion of the forces acting on the wheel. Together with the track rod further to the rear, this special configuration defines the elastokinematic behaviour of the rear axle with ultimate precision.
The 30 millimetre lower ride height compared with an Audi A4, the 37 millimetre wider track at the front and 47 millimetre wider track at the rear, as well as the sporty spring and damper settings, help the RS 4 to meet the developers’ ambitious handling objectives and place it in the realm of a genuine sports car.
Dynamic Ride Control
The Audi RS 4 comes with Audi’s DRC Dynamic Ride Control, which featured for the first time in the Audi RS 6. This system reduces the rolling and pitching movements of the vehicle about its longitudinal and transverse axes in a particularly intelligent way.
This is accomplished by interconnecting the dampers diagonally by way of a central valve. Body movements when driving off are largely eliminated in this way, as are pitching movements when braking, or rolling when cornering fast. This has further enhanced the driving dynamics offered by the RS 4.
DRC has already been supremely well received in the RS 6. In the RS 4, quattro GmbH has succeeded in making the system more compact and lighter. Dynamic Ride Control employs no electronics whatsoever.
The combination of quattro drive, DRC and a suspension layout specifically geared to the RS 4 allows this Audi to hold the road safely even in the absolute limit ranges at top cornering speeds, when other drive concepts have long since come up against their limits. It goes without saying that the Audi RS 4 features the latest generation of ESP designed and configured especially for this car. It now intervenes later and for shorter periods. The cut-in point can moreover be shifted even closer to the limit of handling, for operation on racing circuits, for example, or ESP can be shut down altogether.
18-inch wheels as standard
The RS 4 is fitted as standard with 18-inch wheels and 255/40 R18 size tyres. 19-inch wheels are optionally available. For the RS 4, Audi’s designers produced a range of light and attractive cast alloy wheels of five-spoke design. The special manufacturing method used means the wheels are stronger, thinner and lighter. The tyres are size 255/35 19. The 19-inch wheels can also be optionally fitted with Pirelli P Zero Corsa sports tyres, which are specially designed for the RS 4 for racetrack use.
The servotronic steering has been specially tuned to the requirements of the sports saloon. With its direct response and short travel, it is outstandingly well suited to the overall character of the RS 4.
Audi has likewise adapted the six-speed gearbox to the handling requirements of a sports car. With its precision navigating through the shift gate and its short travel, it enhances driving pleasure and prompts the driver to change gear more often than the universally free-revving engine actually needs.
Brakes for the racetrack
The brakes, too, represent new dimensions in their innovation. The 18-inch format provides impressive deceleration. The perforated and ventilated brake discs measure 365 millimetres in diameter at the front and 324 millimetres at the rear. They are designed in a floating arrangement, meaning that the cast-iron friction ring of the brake system is bolted on to the aluminium brake disc cover. The result is a significant improvement in the brakes’ resistance to fading, particularly under extreme loads. A further side-effect of this technology is a reduction in unsprung masses. The specifically flow-enhanced brake ventilation incorporating NACA jets on the underbody of the car ensures optimum cooling of the brakes, however high a load they are subjected to.
Featuring eight-piston fixed callipers originally developed for motor sport on the front wheels (four pistons and two brake pads on the inside and outside of each brake disc) as well as single-piston floating callipers on the rear wheels, the Audi RS 4 offers supreme stopping power and directional stability.
The brake system incorporating the functions ABS, EBD electronic brake-force distribution and ESP electronic stabilisation system has been specifically tailored to the dimensions of the brake system.
The latest-generation ESP 8.0 has been modified specifically for the RS 4, reflecting the particular properties of this high-performance vehicle. It now intervenes later and for shorter periods. It is also possible to disable the ESP in two stages.
In the first stage only the traction control (ASR) function is disabled; the other ESP functions remain fully active. In the second stage the ESP is completely deactivated, including the traction control. All electronic control then ceases.
An additional boost to safety is provided by the ESP, with its dry braking function. When the road is wet the system lightly applies the brake pads to the discs at regular intervals, to sweep water from them and so improve braking response. The ESP also incorporates the EDL electronic differential lock, traction control, electronic brake-force distribution and ABS.
Design: Self-confidence and functionality
The design of every Audi RS 4 combines functionality with aesthetics. All three models outwardly embody the ultimate in uncompromising sportiness. In particular, an RS 4 demonstrates its enormous performance potential where such qualities really count, boasting features such as:
- Flared wheel arches
- Bumpers in RS design with the trim grille in diamond look
- Flared side sills as well as door cut-out trim strips matched to the sills
- A rear spoiler integrated into the boot lid and side panels
- A twin-chamber exhaust system with oval tailpipes
- Aerodynamically optimised twin-arm design RS exterior mirrors in aluminium look
- Newly designed 18-inch five-spoke alloy wheels (and optional 19-inch wheels of 7 twin-spoke design)
- RS 4 badging at front and rear and on the side rubbing strips
- Trim strips in matt aluminium.
The sporty look is combined with an equally high level of functionality. The large inlets on the front end of the RS 4 guarantee optimum cooling of the V8 FSI engine. Flared wheel arches offer plenty of space for the 18-inch or 19-inch wheels. With enlarged tailpipe cross-sections, the twin-chamber exhaust system provides for significantly reduced exhaust gas counterpressure. The 30 millimetre lower suspension not only provides a sporty look, but is also a major factor in delivering the outstanding levels of driving dynamics the car offers.
The distinctive single-frame radiator grille and the sweeping outline of the headlights, borrowed from the Nuvolari prototype, underscore the family heritage of the three RS 4 versions.
The three RS 4 models are available in nine exterior colours. The range extends from the subtle Avus Silver to the luminous Imola Yellow. And through Audi’s customisation programme, quattro GmbH offers even the most discerning customer a virtually unlimited range of individual colours and combinations.
Interior: The premium sports car
There are countless echoes of motor racing around the interior of the RS 4 models. These include the extensive use of carbon fibre and aluminium. The moment you climb in, it is clear you are taking a seat in a sports car. The engine is started at the push of a button.
Every detail of the interior exudes the premium quality so typical of Audi, coupled with RS-specific sportiness.
In the saloon and Avant, the front passengers are accommodated on sports bucket seats. With their high side sections, these provide maximum support even when the car is driven energetically, for instance round a racetrack. On these seats, the width of the seat base and seat back can be adjusted electrically as preferred. Even greater lateral support can be obtained by pressing the Sport button.
As well as calling up a modified, more progressive engine response with greater spontaneity of throttle response and an even more sporty sound from the exhaust system, this function inflates the seat side sections, supporting the driver even more securely. The RS bucket seats are available either in full leather throughout or in a combination of leather and cloth. Sports seats are available as an option.
The Cabriolet is equipped with leather-upholstered sports seats, which likewise provide very good support but also take the higher comfort requirements of Cabriolet drivers into account. Here too, RS bucket seats are available as an option.
Attention to detail is demonstrated in the choice of materials and the craftsmanship applied in processing them. Leather, aluminium and carbon fibre are the predominant materials in the interior. The flat-bottomed RS steering wheel, developed exclusively for the Audi RS 4, is covered in perforated leather. Carbon-fibre trim inside the car serves to additionally accentuate the sporting qualities of the RS 4. A range of further trim options are also available: Piano finish black, Fine grain myrtle nutmeg and Aluminium matt. A further detail is the design of the milled aluminium door openers, echoed also on the gear lever and steering wheel. The gear knob, handbrake lever and steering wheel are also covered in perforated leather. The aluminium pedals are a further echo of the motor sport world, and also help to save weight.
The driver information system welcomes the driver upon entering the car with the exclusive RS welcome logo. An oil temperature gauge as well as a stopwatch with lap timer function have also been incorporated into the typical RS-design cockpit. Useful extras for those special track days so beloved of RS 4 drivers.
Safety: Superior traction in every situation
The safety package Audi has put together for the RS 4 is both comprehensive and highly sophisticated. Driving safety was a major priority in the development process. The quattro permanent four-wheel drive system already offers more traction than conventional drive systems in critical driving situations. Its variable distribution of power across the two axles now also provides even greater benefit.
Every RS 4 features a tyre pressure monitoring system as standard. The sensors located in the wheels continually measure the tyre pressure at three-second intervals. In the event of an acute loss of pressure, the driver information system gives the driver both a visual warning sign and an acoustic alarm.
Passive safety of the highest standard
A rigid body, comprehensively coordinated deformation properties, state-of-the-art restraint systems - such as the two-stage front airbags - and, last but not least, the sideguard head airbag system provide an exemplary level of occupant protection. This head-level side airbag system covers virtually the entire side window area, from the A-post to the C/D-post. The airbags themselves are inflated by a hybrid gas generator, which maintains the airbag pressure for several seconds to provide ongoing protection.
This means sideguard provides full protection even in a secondary collision such as when the car rolls over following initial impact. And the new RS bucket seats, in conjunction with the belt system, offer additional safety and restraint in the event of a side-on collision so that the RS 4 does not even require side airbags in order to meet the stringent crash test requirements.
Equipment: Light and comprehensive
Although weight was one of the main considerations in the development of the Audi RS 4, the car boasts an extensive range of equipment. Standard features include a deluxe automatic air conditioning system, as well as the concert radio system. Central locking and electric windows are also featured as a matter of course in a car of this class.
The acoustic parking system at the front and rear protects against irritating dents and scratches when parking. The high-intensity xenon plus headlights provide optimum visibility.
The RS logo is worked into the flat-bottomed leather sports steering wheel as well as in the seat upholstery and door sills. Two of the functions controlled directly from the ergonomically designed RS sports steering wheel are the lap timer and the Sport button.
Dynamic Ride Control (DRC) provides sporty, dynamic handling by significantly reducing body roll and pitch. All RS 4 models come with 18-inch cast aluminium wheels of 5-spoke design. As an optional extra, there are 19-inch wheels of 7 twin-spoke design. Here, too, weight saving is combined with sporty design.
Audi offers an extensive range of optional extras for the RS 4. They include the navigation system plus, the symphony radio system, additional exterior mirror versions (optionally also folding), as well as the sports suspension plus. The comfort package comprises features such as cruise control as well as heated front seats.
For customer preferences above and beyond this range, quattro GmbH, which is also responsible for the “S line” range of optional equipment and for “lifestyle articles” at Audi, offers an extensive customisation service that goes by the name of Audi exclusive.
RS Models
The new Audi RS 4 is the latest offspring of the RS family from quattro GmbH. The debut of the first RS 4 in 1999 - at the time the first high-performance model independently produced by the Audi subsidiary - attracted lots of admiring looks. At the same time it redefined the concept of a high-performance vehicle. In a truly impressive manner, the first RS 4 demonstrated the immense future potential of Audi’s sporty models.
And Audi’s first RS model also impressed its fans right from the off. The RS 2 Avant amazed the motoring world with its performance. This five-cylinder turbo model entered the market in 1994 and was built for a little over a year. Its engine delivered 262 kW (315 bhp). 2,881 customers opted for this sports car, which was based on the Audi 80 Avant. The RS 2 has long since become a sought-after classic with a loyal fan club.
The first-generation RS 4 demonstrated what still singles out every RS vehicle to this day: an uncompromising combination of emotion and functionality.
The very first Audi RS 4 Avant attracted customers thanks to its outstanding combination of family practicability and everyday motoring qualities blended with driving performance, something that had previously been the exclusive preserve of thoroughbred sports cars.
Its success was impressive: although the RS 4 remained in production for just 14 months, more than 6,000 customers opted for this sports car in its Avant body style during that time.
And the RS 6 that succeeded it rapidly attracted an enthusiastic fan club of its own. Towards the end of its production run the limited-edition 480 bhp RS 6 plus also appeared on the market. The RS 6 was the first RS model to be sold both as a saloon and an Avant. Altogether over 8,000 examples of the RS 6, including the RS 6 plus, were sold worldwide.
By creating the new Audi RS 4, quattro GmbH has proved once again that there is no need for compromise in developing a sports car fully suited to everyday motoring. Indeed, the RS models highlight the engineering and technological expertise of Audi more than virtually any other car.
The RS models from quattro GmbH are emotionally exciting sports cars which have to date attracted a large and enthusiastic fan base. That success will continue with the new RS 4.
RS drivers have already grown accustomed to these perfect, highly emotional driving machines that are eminently suitable for everyday driving. As a result, these cars have attracted an enthusiastic following. And they will go from strength to strength with the three new RS 4 versions.
[source: audi-press.com]
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