Audi RS 4

The Audi RS 4 quattro is the top tier and highest performing version of some specific generations of the Audi A4 range of automobiles. It is a sports-focusedcompact executive car (often called sport compact in some countries), producedby Audi's high-performance private subsidiary quattro GmbH, in limited numbers, for German car manufacturer AUDI AG, part of the larger Volkswagen Group. It slots distinctly above the Audi S4, as the fastest, most sports-focused model based on the A4's "B" automobile platform. The RS 4 made a comeback in 2012, in Avant form only based on the Audi A4 Avant.

The original B5 version was only produced as a five-door five-seat "Avant", Audi's name for an estate car/station wagon. The second version, the B7, was released initially as a four-door five-seat saloon/sedan, with the Avant following a short while later. A two-door four-seat Cabriolet version was subsequently added. Furthermore, their unique internal combustion engines are all front-mounted, and arelongitudinally oriented. The transmission is mounted immediately at the rear of the engine in a longitudinal orientation, in the form of a transaxle, and contains both a center and front differential.

The "RS" initials are taken from the German: RennSport—literally translated as "racing sport", and is the Audi marque's highest trim level, positioned above the"S" model specification of Audi's regular model line-up. Like all Audi "RS" cars, the RS 4 pioneers some of Audi's latest advanced technology, and could therefore be described as a "halo vehicle". Furthermore, it is only available with Audi's Torsen-based "trademark" quattro permanent four-wheel drive system.

Its main market competitors include the BMW M3, Mercedes-Benz C63 AMG, andLexus IS-F.

Audi RS 4 quattro

Audi RS 4 (B7) quattro Avant
Manufacturer	quattro GmbH, (a private subsidiary of AUDI AG)
Production	B5: 2000–2001 B7: 2006–2008 B8: 2012–
Assembly	Neckarsulm, Germany
Class	Compact executive Sports car
Layout	Longitudinal front engine, quattro permanent four-wheel drive
Platform	Volkswagen Group B platform series
Related	Audi A4 Audi S4

B5 (Typ 8D, 2000–2001) 

The original B5 Audi RS 4 Avant quattro (Typ 8D) was introduced by Audi in late 1999, for main production and sale from 2000, as the successor to the Porsche / quattro GmbH joint venture-developed Audi RS2 Avant. The vehicle, like its RS2 predecessor, was available only as an Avant and was built on an existing platform, in this case theVolkswagen Group B5 platform shared with the A4 and S4. Retail price was around DM 103,584. The RS 4 was available for sale in most of Europe, parts of Asia and in some Latin American countries.

B5 bodywork and styling 

Although related to the Audi B5 S4, many of the outer body panels were altered, with wider front and rear wheel arches, to allow for the wider axle trackon the RS 4. With unique front and rear bumpers and side sills, and the rearspoiler from the S4 Avant, the aerodynamic modifications achieved a drag coefficient of C_d 0.34. Although the B5 S4 came in a saloon car body style, the B5 RS 4 was only available in the Avant version.

Luggage space, measured according to the industry standard VDA method was 390 litres (13.8 cu ft) with the rear seats in the upright position, and 1,250 litres (44.1 cu ft) with the seats folded flat.

B5 powertrain 

The engine was developed from the 2.7 litre 90° V6 'biturbo' used in the B5 S4. It displaced 2,671 cubic centimetres (163.0 cu in) and had five valves per cylinder. The parts code prefix was 078 and the identification codes were: early version, 2000 (EU2 compliant): ASJ, and later version, 2000-01 (to EU3 standard): AZR. This engine was developed and manufactured in the UK by Cosworth Technology (now known as MAHLE Powertrain). It featured enlarged intake and smaller exhaust ports on the two Cosworth cast aluminium alloy ALSi7mgcylinder heads, two parallel BorgWarner K04-series turbochargers, two larger side-mountedintercoolers (SMICs), dished piston crowns, stronger connecting rods, larger intake ducting, enlarged exhaust system, and a re-calibrated engine management system. The modifications increased the engine's output from 195 kilowatts (265 PS; 261 bhp) and 400newton metres (295 lbf·ft) of torque in S4 form to 280 kilowatts (381 PS; 375 bhp) at 7,000 revolutions per minute (rpm) and 440 newton metres (325 lbf·ft) at 6,000 rpm. The engine was controlled by a Bosch Motronic ME 7.1 electronic engine control unit (ECU), using a Bosch 'E-Gas' electronic drive by wire throttle. The engine had multipoint sequential fuel injection, a MAF, six individual single-spark coils and NGK longlife spark plugs. The engine oil was cooled by a dual oil:water cooler and an oil:air cooler.

A six-speed manual transmission (parts code prefix: 01E, identification code: FDP) (gear ratios—1st: 3.500, 2nd: 1.889, 3rd: 1.320, 4th: 1.034, 5th: 0.806, 6th: 0.684), cooled by aNACA duct in the engine undertray, and Audi's Torsen-based quattro system, using the Torsen T-2 "automatic torque biasing" (ATB) center differential, with a 50:50 default bias were standard. Final drive ratio was 4.111.

Even with a kerb weight weight of 1,620 kilograms (3,571 lb), the RS 4's powerful engine gave it the performance of a sports car. 100 kilometres per hour (62.1 mph) could be reached from rest in 4.9 seconds, 160 kilometres per hour (99.4 mph) in 11.3 seconds, and 200 kilometres per hour (124.3 mph) in 17.0 seconds. Top speed was electronically limited to 262 kilometres per hour (162.8 mph).

B5 brakes, wheels and tires 

Brakes were also developed jointly in house by Audi's quattro GmbH, not by Porsche as with its predecessor, the RS 2. At the front they were radially vented and floating cast iron discs, 360 millimetres (14.2 in) diameter and 32 millimetres (1.26 in) thick, with double-piston floating calipers, and at the rear 312 millimetres (12.3 in) by 22 millimetres (0.87 in) discs with a single-piston floating caliper. The RS 4 needed less than 50 metres (160 ft) to come to a full stop from a speed of 110 kilometres per hour (68 mph).

The standard wheels were 18 inch alloys (8½×18" "9-spoke"), with 255/35 ZR18 high performance tyres. Optional "winter" alloy wheels were also available, at 18 inch (7½J×18"), with 225/40 R18 92V tyres.

B7 (Typ 8E, 2006–2008) 

There was no RS 4 built on the Audi"B6" platform that served as the basis for the Audi A4 between 2001 and 2005. However, after a long hiatus, the second Audi RS 4 quattro (Typ 8E), was built on Audi's "B7" A4 platform, by quattro GmbH in Neckarsulm, Germany. It was unveiled in February 2005 at Audi's 'quattro Night' celebration at the company headquarters in Ingolstadt, Germany.

An Imola Yellow RS 4 saloon came down a replica of a ski jump, then rotated several times on an ice rink, before coming to rest in the centre of the ice. After several minutes to allow the assembled media and guests to examine the car, the RS 4 climbed the ski jump and parked near the top. The ski jump was a homage to an Audi commercial from 1986; where an Audi climbed a ski jump in Finland to showcase its superior traction due to Audi's trademark quattro drivetrain.

The RS 4 became available toEuropean customers in mid-2006. It was introduced at the 2006 North American International Auto Show in January, and arrived in June 2006 inNorth America. The production run of the B7 RS 4 was 2006 to 2008 inclusive, although only 2007 and 2008model year were sold in the United States. To date, approximately 10,000 B7 RS 4s have been built, of which around 2,500 are in the USA.

The B7 RS 4 Cabriolet, available in Europe from late 2006 to 2008, was made available as a model year 2008 vehicle in the USA.

Audi factory numbers indicate that the B7 RS 4 saloon can accelerate from 0 to 100 kilometres per hour (0 to 62.1 mph) in 4.8 seconds, and arrive at 0 to 200 kilometres per hour (0 to 124.3 mph) in 16.6 seconds.Most European magazines recorded results in line with the November 2009 comparison of "ultimate sedans", in Road & Track, which recorded a 0 to 60 time of 4.5 seconds. This is consistent with the pattern of conservatism that is usually found in Audi's official performance numbers. For the Avant, 0 to 100 kilometres per hour (0 to 62.1 mph) is reached in 4.9 seconds. Top speed for all variants is "officially" electronically limited to 250 kilometres per hour (155.3 mph), though some owners have reported that the speed limiter is rather "liberal", conforming to the pattern of previous Audi "RS" cars, with genuine top speeds of 270 kilometres per hour (170 mph) being recorded.

B7 bodywork and styling 

The B7 RS 4 is an almost complete departure from previous Audi "RS" cars, as it was initially available as a four-door five-seatsaloon/sedan; with a five-door five-seat Avant (estate/wagon), and two-door four-seat Cabriolet (convertible) versions arriving later. Only the Audi RS 6 had taken this similar route (saloon and Avant) before; the previous RS 4 and RS 2 were available exclusively as Avants.

Constructed from fully galvanised steel in a monocoque (unitary/unibody) design, the B7 RS 4 uses lightweight aluminium for its front wings (fenders) and bonnet (hood). The saloon version features a drag coefficient (C_d) of 0.31, from a frontal area of 2.17 m².

Like its B5 predecessor, visually, the B7 RS 4 differs from its related B7 S4, by having even wider flared front and rear wheel arches (fenders), to allow for a wider axle track. Over the B7 A4, it also includes two larger frontal side air intakes (for the two additional side-mounted coolant radiators). The trim on the saloon and roof rails on the estate are chrome as standard but can also be found in black with the addition of the Optic Pack which includes a black front grill, all exterior trim and black roof rails on the estate version. The B7 RS 4 also includes an optional adaptive headlights to complement the standard "Xenon Plus"(Bi-Xenon arc) High Intensity Discharge (HID) headlamps, which swivel around corners in conjunction with steering wheel movements. Also standard are daytime running lights (DRLs), found within the main headlamp housings, identical to its related B7 A4 and S4, and use a conventional tungsten filament bulb. An acoustic parking system with front and rear sensors is also a standard fitment. Unique carbon fibre interior trims, along with a lap timer within the central Driver Information System (DIS), aluminium pedal caps and footrest, and RS 4 logos complete the look.

In the saloon, luggage space, measured according to the VDA 'block method', is 460 litres (16.2 cu ft) with the rear seats in the upright position, and 720 to 833 litres (25.4 to 29.4 cu ft) with the seats folded flat (dependent on specification). For the Avant, 442 litres (15.6 cu ft) is available with the seats upright (under the retractable load cover), and 1,354 litres (47.8 cu ft) being available with the rear seats folded flat (loaded to the roofline). Kerb weight of the saloon variant starts at 1,650 kilograms (3,638 lb) (dependent on specification).

A BOSE ten-speaker sound system, with 190 watt output and automatic dynamic noise compensation (which replaces the 'GALA' found on earlier units), with "Concert II" radio and single CD player is standard in car entertainment (ICE) equipment. Factory fitted ICE options to complement the standard BOSE include the "Symphony II" system which features twin radio tuners, a single-slot loading six-CD changer and a cassette player all integrated into a double-DIN sized unit. Navigation option is the RNS-E "Audi Navigation System plus" DVD-ROM GPS satellite navigation, which includes a folding widescreen 6.5-inch screen, two SD-memory card readers, and MMI-like logic control.

B7 interior safety 

o achieve maximum body stiffness with controlled deformation crumple zones, the B7 RS 4 features laser beam welding of major seams of the high-strength steel body shell, which helps improve overall structural rigidity, particularly in the "passenger cell", over traditional spot welding methods.

Two-stage driver and front seat passenger frontal airbags are standard,as is Audi's "sideguard" head protection curtain airbag system. This latter system completely covers all of the side windows, from the front 'A pillar' to the rear "C-" or "D pillars". The body-hugging Recaro shell-type RS race bucket seats (not available in North American markets), complete with electrically inflatable upper and lower side bolsters and adjustable lumbar support, are constructed so as not to need lower side airbags to comply with European crash safety standards. In North America, the only front seats available are the more traditional Recaro seats (identical to those in the B6 and B7 S4), which include lower side airbags; these were also available as a no-cost option in other markets. Lower side airbags are optional for the standard-fit Recaro rear seats. Front, and outer rear seatbelts include pyrotechnic belt pretensioners, whilst all belts include an excess load limit function.

B7 powertrain

The engine of the B7 RS 4 is started by an "Engine Start" button on the centre console and is based on the existing all-alloy 4.2 V8 from the B6 S4, and shares many parts, and Fuel Stratified Injection, with the 4.2 FSI V8 engine in the Q7. The engine includes new cylinder block construction, and is a highly reworked, high-revving variant (redline at 8,000 rpm; rev limit of 8,250 rpm).

The engine has increased crankcase breathing, a low-pressure fuel return system and a baffled oil sump, to prevent engine lubricant cavitation at high engine speeds and high-G cornering. It has four valves per cylinder (instead of five on the earlier variant) and two overhead camshafts on each cylinder bank (so it is 'quad cam') and these are driven by roller chains with variable valve timing  for both inlet and exhaust camshafts, along with a cast magnesium alloy fixed tract length intake manifold with adjustable tumble flaps (to improve low engine speed combustion). On 98 RON (93 AKI) Super-Unleaded petrol it produces 309 kilowatts (420 PS; 414 bhp) at 7,800 rpm  giving it a specific power output of 74.2 kW (100.9 PS; 99.5 bhp) per litre. Based on a kerb weight of 1,680 kilograms (3,704 lb), this results in a power-to-weight ratio of 184 watts per kilogram. This engine also produces 430 newton metres (317 lbf·ft) of torque at 5,500 rpm, 90 percent of the total torque being available between 2,250 and 7,600 rpm. (Using lower 95 RON (91 AKI) standard unleaded fuel slightly reduces engine output, and therefore performance, and slightly worsens fuel economy). Exhaust gas escapes through two '4-into-2-into-1' fan-branch alloy steel exhaust manifolds and four high-flow metallic sports catalytic converters,into twin oval tail pipes with integral dynamic silencer/muffler valves. The engine is controlled by two Bosch DI-Motronic MED 9.1electronic engine control units (working as 'master' and 'slave', because of the high-revving nature of the engine), and uses Bosch 'E-Gas' electronic throttle control (also known as drive by wire), comprising throttle device, accelerator-pedal module, and ECU. Theignition system uses eight individual single-spark coils, using mapped direct ignition, with Bosch single iridium electrode or NGKtriple-electrode long-life spark plugs. Ignition timing is monitored with the aid of four knock sensors. The engine complies with the Euro4European emission standards. The saloon version produces 322-329 grams of CO₂ per kilometre (g/km), and the Avant starts from 324 g/km.

A six-speed Getrag manual gearbox (parts code: 0A3, identification codes: HLD, JHM) is the only transmission available. The gear ratios are 1st: 3.667, 2nd: 2.211, 3rd: 1.520, 4th: 1.133, 5th: 0.919, 6th: 0.778.

The Audi B7 RS 4 was the only "RS" Audi powered by a naturally aspirated engine until the Audi RS5 was presented at the 2010 Geneva Motor Show. The RS5 also uses a 4.2 litre high revving V8, which puts out 450 horsepower, however the RS5 engine is based on the 5.2 liter V10 in the R8, and is not related to the RS4 engine.. The RS5 also dropped the Getrag 6-speed manual in favour of a 7-speed "S tronic" dual clutch semi-automatic.