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Tuesday, December 9, 2008

Audi RS 6

Audi RS 6






A second generation RS6 5.0 TFSI quattro (Typ 4F) based on the Volkswagen Group C6 automobile platform was launched at the Frankfurt Motor Show in September 2007. Available in Europe from April 2008, and as of July 2008, it is Audi's single most powerful car ever to be produced by the marque, and positions the car ahead of its main competitors, the BMW M5 and the Mercedes E63 AMG in terms of engine output.

The RS6 Avant will not be available in the U.S. market. However, a saloon (sedan) was unveiled in August 2008, and is likely to be offered in North American markets.

Official performance figures for the Avant: 4.6-second 0-100 km/h (62 mph), 14.9 seconds 0-200 km/h (124 mph), and top speed is electronically governed to 250 km/h (155.3 mph), with a factory option to derestrict the top speed to 274 km/h (170.3 mph). In standard form, CO2 emissions are rated at 333 g/km.

Powertrain

The engine is an all-aluminium alloy 4991 cc 90° V10 twin-turbocharged Fuel Stratified Injection (FSI), with a dry-sump lubrication system, and a unique firing order. It has four valves per cylinder, with twin chain-driven double overhead camshafts, and variable valve timing for both inlet and exhaust camshafts. Charged intake air is cooled with two side-mounted intercoolers (SMIC)s. The engine produces 580 PS (427 kW/572 bhp) at 6,250 to 6,700 rpm, and 650 N·m (479 ft·lbf) of torque from 1,500 to 6,250 rpm. Engine management is by way of Bosch Motronic ME 9.1.2 engine control unit, incorporating two integrated control units which act as "master" and "slave" concepts. It also uses mapped direct ignition with ten individual spark coils, an electronic drive by wire throttle ("Bosch E-Gas"), cylinder-selective knock control, and cylinder bank adaptive lambda control, utilising eight lambda sensors.

A total of seven radiators, and four electric cooling fans are needed to cool the engine and related components under the bonnet of the RS6.

This RS6 overtakes the position (in engine output) from the BMW M5, making about 70 bhp (52 kW) and 150 N·m (111 ft·lbf) more than BMW's naturally-aspirated V10 engine.

Drive passes through a modified six-speed tiptronic automatic transmission (gear ratios - 1st: 4.171, 2nd: 2.340, 3rd: 1.521, 4th: 1.143, 5th: 0.867, 6th: 0.691), with shortened shift times, with "Dynamic Shift Programme" (DSP) and "Sport" mode. It has paddle-shifts mounted behind the flat-bottomed steering wheel, similar in design to the B7 RS4. The gearbox is set by default, in conventional automatic mode, to delay up-changes during acceleration, and change down earlier to maximise engine braking. Downchanges in all modes of operation include the Powertrain Control Module ECU "blipping" the drive by wire throttle, for smoother shift changes. The hydraulic torque converter includes a lock-up function.

Like all Audi RS models, the RS6 is fitted with quattro permanent four-wheel drive as standard; including the latest asymmetric dynamic 40:60 front-to-rear default torque distribution from the Torsen T-3 centre differential. This latest incarnation of the Torsen quattro, first seen in the B7 RS4, can dynamically apportion up to a maximum 100% torque to the rear axle, or up to 80% to the front, dependent on traction conditions.

The front and rear axle final drives are conventional "open" differentials (ratio 3.317), and use the Audi "Electronic Differential Lock" (EDL). EDL is a part, or "function" of the Bosch ESP 8.0 Electronic Stability Programme, which also includes "Anti-Slip Regulation" (ASR) traction control system.

Steering and suspension

Like the previous RS6 and the B7 RS4; this generation RS6 includes Audi's "Dynamic Ride Control" (DRC) Sports suspension system. The system is mainly mechanical; using a pump to provide additional pressure in the diagonally linked shock absorbers during cornering, to counteract rolling and pitching. The system can dynamically adjust the stiffness at each shock absorber constantly to maintain both a comfortable ride and high grip. On this version, it has a three-way level control, selectable from the Multi Media Interface controls.

The steering system includes rack and pinion speed-dependent "servotronic" power steering, with a ratio of 12.5, and a turning circle of 12.2 metres.

Brakes, wheels & tyres

Standard brakes on the RS6 consist of drilled, radially vented and floating iron discs, the front discs sized at 390 mm (15.35 in) in diameter by 36 mm (1.417 in) thick, and the rears at 356 mm (14.02 in) diameter by 28 mm (1.102 in). The front discs are clamped by gloss black 6-piston fixed Brembo monobloc alloy calipers incorporating the "RS" logo, and black single-piston floating calipers, with integrated electro-mechanical parking brake linkage actuating on the rear discs.

Optional "Audi Ceramic" Carbon fibre-reinforced Silicon Carbide (C/SiC) composite front brakes are available, only with 20 in wheels, which use 420 mm (16.54 in) diameter by 40 mm (1.575 in) thick drilled, vented, and floating SGL Carbon discs, with grey painted 8-piston fixed Alcon monobloc alloy calipers. Irrespective of the type of disc constrution, all brake discs are mounted via high strength steel mounting pins which connect the 'working' surface of the disc to lightweight alloy disc hubs.

A "sport-biased" Bosch ESP 8.0 Electronic Stability Programme is standard, and includes Anti-lock Braking System (ABS) and Electronic Brakeforce Distribution (EBD).

Standard road-wheels (in the UK) are 9.5Jx20 inch '5-segment-spoke' design alloy wheels running on 275/35 ZR20 102Y tyres (rated at 850 kg (1,874 lb) per tyre), with a no-cost optional 9.5Jx20 '7-arm double spoke' design (identical style to B7 RS4), or 9Jx19 inch '10-spoke' design alloys with 255/40 ZR19 tyres.

Bodywork and styling

Initially, the new RS6 will only be available as a five-seater, five-door Avant (estate/wagon) version. Constructed from steel in a monocoque (unibody) design, the RS6 uses aluminium for its front wings and bonnet. A four-door saloon/sedan is scheduled to be available from late 2008.

Visually, the RS6 differs from its related Audi S6, having flared front and rear wheel arches, to allow for a wider track, and the deletion of front fog lights to allow for larger frontal air intakes (for the twin side-mounted intercoolers and additional radiators). The ten (per side) front light-emitting diode (LED) daytime running lights (DRLs), found on the S6 adjacent to the fog lamps in the lower front bumper, are now found within the main headlamp housing on the RS6. LED lighting technology is implemented in the rear lights. The new RS6 also includes adaptive headlights, which swivel around corners in conjunction with steering wheel movements.

Luggage capacity in the Avant ranges from 565 litres (L), to 1660 L.

Other notable features

* Electro-mechanical parking brake, which doubles as a full emergency brake whilst in motion (applying maximum braking effort to all four wheels, activating the anti-lock braking system (ABS)),
* Three-stage sports-biased Bosch 8.0 Electronic Stability Programme (ESP) - standard full protection mode, ESPsportmode, ESPoff.
* DAB digital radio tuner with DVD-based satellite navigation and Multi Media Interface (MMI), with optional hybrid digital/analogue TV tuner.

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