|22 May 2000
The RS4 by quattro GmbH
The RS4, a high-performance vehicle with uncompromising sports character in terms of both technology and visual appearance, is being launched on the market by quattro GmbH. quattro GmbH has designed the RS4 on the basis of the Audi S4 Avant as the supreme model in the A4 series and developed it in conjunction with AUDI AG.
The RS4, which, like its predecessor the RS2, is to be produced exclusively as an Avant model, will impress discerning customers who favour sports-style driving, thanks to its superlative performance. Such qualities are assured by a 280 kW (380 bhp) V6 biturbo engine, permanent four-wheel drive, overtly sporty suspension tuning and a high-tech brake system to suit the engine's high performance.
The RS4 has cast off the visual understatement which typifies the S4: the strikingly flared wheel arches, the 18-inch alloy wheels, the front apron extending well down, with its large air inlets, the aerodynamically styled tail and the side sills harmoniously integrated into the body line unmistakably emphasise the character and performance of the RS4. The RS4 is entirely geared up for sheer sports performance, without losing sight of the need for everyday suitability.
Engine and transmission
As on the S4, a 2.7-litre biturbo V6 engine with five valves per cylinder gets to work under the hood of the Audi RS4. Audi's engineering experts have taken what was already a very high-performance engine and given even more power and torque to the version used on the RS4.
Instead of 195 kW (265 bhp) in the S4, the RS4 engine develops a permanent peak output of 280 kW (380 bhp) at between 6,100 and 7,000 rpm. The V6 biturbo's peak torque of 440 Newton-metres is available throughout an extremely wide speed range from 2,500 to 6,000 rpm.
The Audi six-cylinder engine has all the trappings of an out-and-out powerhouse: five valves per cylinder, the two separate turbochargers on each bank of cylinders, the hydraulically adjustable intake camshafts, the single-spark ignition coils and the modern engine management system - the Bosch Motronic ME 7, with boost pressure, knock and exhaust-gas temperature control.
In conjunction with the British company Cosworth Technology, which has been part of the Audi Group since 1999, the cylinder head has been redesigned and produced using a specially developed casting technique. The admission and exhaust ports have been modified in line with the engine's higher performance, and the cross-section of the air ducts at both the intake and thrust side enlarged. The turbochargers have moreover been enlarged and the boost pressure has been increased compared with the S4. Thanks to the use of larger charge-air coolers with less pressure loss, efficiency has been clearly enhanced further. The engine cover on the Audi RS4 is made from carbon-fire composite material.
The engine's efficiency is also boosted by the new dual-branch exhaust system developed by quattro GmbH, with backpressure-optimised middle and rear silencers, larger-section pipes, and primary and main catalytic converters with a metal base.
The six-speed manual gearbox with ratios made even sportier especially for the RS4 (the third and fourth gear ratios have been reduced by seven percent), together with permanent four-wheel drive, converts the high torque of the biturbo V6 into propulsion and traction effectively and with excellent directional stability. The RS4 sprints from 0 - 100 km/h in 4.9 seconds; it takes 17.0 seconds to reach a speed of 200 km/h from a standstill. Its electronically governed top speed is 250 km/h.
In keeping with these superior performance data, the RS4's brake system has been completely redeveloped. Much larger composite-type brake discs have been fitted on both the front and rear wheels. This technology, adopted from the world of motor sport, involves fixing the cast friction ring to an aluminium brake-disc chamber by means of 14 pins. This "floating" arrangement significantly improves the stability and shielding of the brake discs, particularly when exposed to extreme loads and at high disc temperatures. The weight reduction is a further advantage.
The diameter of the ventilated brake discs is 360 mm on the front axle and 312 millimetres at the rear. There is a dual-piston floating caliper on the front axle, and a single-piston floating caliper on the rear axle. The parameters of the ABS system and the electronic brake-force distribution system have been specifically modified to reflect the increased dimensions of the brake components.
The 18-inch wheels provide space for the RS4's more voluminous brake system. The 8.5 J x 18 cast aluminium wheels with a new nine-spoke design have 255/35 ZR 18 tyres at front and rear. The 7.5 J x 18 winter wheel with five-spoke design is fitted with tyre size 225/40 R 18 M+S.
The vehicle body has been lowered by around 20 millimetres compared with the A4. The control arms of the four-link front suspension and the swivel bearings are of aluminium. The spring/shock absorber units and elastokinematics have been retuned to suit the modified axle weights and axle geometry. Rack-and-pinion steering with a direct ratio also contributes towards the vehicle's distinctly sporty handling.
The Audi RS4 is equipped with the electronic stability program ESP as standard. This combines the established functions of ABS with Electronic Brake-force Distribution (EBD), Electronic Differential Lock (EDL) including manipulation of the brakes, Anti-Slip Regulation (ASR), engine drag torque control (MSR) and the higher-level yawing moment controller.
In keeping with the strict quality specifications of AUDI AG, quattro GmbH has subjected the RS4 to rigorous vehicle testing. As well as numerous everyday tests in extreme climatic conditions and road endurance tests covering several 100,000 kilometres, the RS4 also completed two extensive endurance tests on the racetrack: one over 8,000 kilometres on the North Loop of the Nürburgring and one over 26,000 kilometres on the high-speed test bowl in Nardo, Southern Italy.
The Audi RS4 is outwardly very different from the A4 on which it is based. The suspension tuning and the wide 18-inch tyres are not the only evidence of this Avant model's sporting constitution. The RS4's body has undergone a whole range of specific modifications, resulting in shapes where the principle of "form follows function" invariably applies and giving this high-performance estate car the dynamic charisma of a top athlete.
On the RS4, the 18-inch alloy wheels are housed inside redesigned wheel arches, flared at both their front and rear edge by 35 millimetres. The broadening of the rear side section continues in the contours of the rear doors. The decision to omit side rubbing strips has also resulted in clearly distinct driver and front-passenger doors. Sills accentuate the sporty side-on appearance.
The front end of the RS4 is dominated by three large air intake ducts: the central aperture is for the water and oil cooling, and those on the left and right are for the charge-air cooling.
The exhaust air from the intercooler escapes through two vents in the sides of the front apron. The trim grilles on the air intake apertures and radiator are aerodynamically optimised, of a honeycomb pattern. The fog lights are integrated into the two outer air intake shafts.
The rear apron echoes the design principle of the front end with its three small, visually identical grille inserts. The exhaust gas emerges through two oval tailpipes beneath the left-hand "aperture". There is a spoiler on the roof edge of the tailgate, for additional downforce. All add-on components are of plastic.
Six exclusive paint colours underline the RS4's sporting flair: customers can choose from Avus Silver, Misano Red, Imola Yellow, Nogaro Blue, Goodwood Green and Brilliant Black. The standard roof rails, roof trim strips, window capping strips, door mirrors and radiator grille frame have a matt aluminium finish and are as such among the more restrained external features of this, the most powerful A4; this can also be said for the RS4 logo on the radiator grille, tailgate and sill strips with RS4 lettering.
The interior of the Audi RS4 is characterised by sports appeal combined with individuality and exclusivity. The individual interior equipment features, made from choice materials, are visually coordinated to produce a harmonised overall appearance in which the colour Onyx pre-dominates.
The Recaro seats for driver and front passenger in a design specific to the RS4 are a standard feature, providing stability, optimum lateral support and ample comfort, however long the journey may be.
Three different types of seat upholstery are available, again as standard: black Valcona leather, silver satin-effect nappa leather and a leather/fabric combination. With this latter option, the side sections and the head restraints are in black pearl nappa, whereas the centre panel of the seat is in textile with a woven-in aluminium thread.
The range of door panel inserts in leather reflects the options for the seat upholstery. The trim strips in the doors, centre console and instrument panel are available in a choice of black piano varnish or carbon. The steering wheel rim and gear lever knob are trimmed with perforated leather. As an option, the rim of the sports steering wheel and the gear lever knob can also be supplied in black or silver Alcantara, to match the leather seats. An eye-catching aluminium ring adorns both the airbag unit in the steering wheel and the knob of the redesigned gear lever. Instead of chrome, the inside door handles, the release button on the handbrake and the gearbox gate ring are made from matt black anodised material.
The standard equipment specification of the RS4 includes significantly more features than that of the S4: in addition to the Recaro seats and the leather seat upholstery, heated seats and the "concert" radio with a 170 Watt Bose sound system are available at no extra charge. It goes without saying that the diverse products in quattro GmbH's customisation range are also available for the Audi RS4.
The safety equipment of the RS4 includes driver and passenger airbags, side airbags at the front, and - optional - Audi's SIDEGUARD head airbag system.
The Audi RS4 is the first model to have been created by quattro GmbH in its own right and developed in conjunction with Audi AG. Together with its special model series, the customi-sation range, exclusive accessories and lifestyle articles, the RS model series is a further significant product range of this Audi subsidiary.
The RS4 is being built jointly by the Ingolstadt plant and quattro GmbH in Neckarsulm. Final assembly and finishing are carried out by hand at quattro GmbH, at the rate of no more than a few cars each day.
The Audi RS4 is scheduled for market launch in mid-2000.