The Mercedes-Benz SLR McLaren is an impressive testament to the competence and experience of Mercedes-Benz and our Formula 1 partner McLaren in the development and production of high-performance sports cars. The two-seater, with its striking swing-wing doors and styling elements borrowed from the Formula 1 Silver Arrows, builds on the legacy of the famous SLR race cars of the 1950s.
The 21st-century Gran Turismo is made almost entirely from carbon fibre composite. This lightweight yet extremely rigid material originated in the aeronautical and space industries and has also proven its benefits in today's Formula 1 race cars. The weight advantage of the high-tech material over steel is around 50 percent, and the carbon fibres, on impact, are characterised by four to five times higher energy absorption than steel or aluminium. Mercedes-Benz exploits these qualities by incorporating two 620-millimetre longitudinal members made from carbon fibre in the front structure of the new SLR. High-strength bonding and riveting techniques are used to connect the individual carbon components of the chassis and the bodyshell. The aluminium engine mounts are bolted to the carbon bulkhead and also bonded in place. The carbon structure includes integral metal link points for the aluminium and steel rear axle.
In the interests of optimum dynamic handling and high stability on braking, the new Mercedes-Benz SLR McLaren has a front mid-engined design. The high-performance V8 engine, mounted on a robust aluminium frame, is installed at a low level which allows a low centre of gravity for agile handling. With its 5.5-litre displacement, the supercharged engine develops a peak output of 460 kW/626 hp and delivers its maximum torque of 780 Newtonmetres from 3250 rpm a figure which remains constant across a broad engine speed range of up to 5000 rpm. This means that the SLR 8-cylinder is among the most powerful engines currently available in a series-produced roadgoing sports car. This high-performance car takes just 3.8 seconds to sprint from 0 to 100 km/h, it passes the 200 km/h mark after 10.6 seconds, and from a standing start it takes just 28.8 seconds to reach 300 km/h. The top speed is 334 km/h. To ensure good cylinder charging, the engine has a mechanical compressor with two screw-type aluminium rotors which, in the interests of low friction losses, are Teflon-coated. The charger is so compact that the engine specialists were able to install it between the two cylinder banks of the V8 powerplant. Despite the space-saving design, its innovative technology allows a significantly higher charge pressure than conventional mechanical chargers because the two rotors achieve a top speed of around 23,000 revs per minute, forcing air into the air inlet of the 5.5-litre powerplant at a maximum pressure of 0.9 bar. Water-type charge-air cooling, dry sump lubrication and four metal catalytic converters are further special features of this powerful engine an engine which already meets stringent EU 4 exhaust gas regulations which are not due to come into force until 2005.
The SLR's high-performance engine draws its fuel from two interconnected aluminium tanks. They are installed at a relatively low level to the left and right of the rear axle in order to keep the centre of gravity as low as possible to further enhance dynamic handling. The tanks, which have an overall capacity of 97.6 litres of which twelve litres form the reserve are equipped with two integral high-pressure fuel pumps. These are controlled by the engine management system and ensure that the fuel supply matches the engine speed and load.
The 5-speed automatic transmission, fitted as standard, is also designed for high performance. It allows the driver to choose between three programs with different shift characteristics. When "Manual" is selected, the five gears can either be shifted using buttons on the steering wheel or using the selector lever's Touchshift function. In this mode the driver can also select between three shift stages "Sport", "SuperSport" and "Race" significantly shortening the shift times still further for an even sportier drive.
Aluminium was the ideal material for the developers of the new Mercedes-Benz SLR McLaren's chassis. The wishbones are made from forged aluminium, while the wheel mounts are cast in aluminium. In addition to a whole series of other advantages over conventional steel designs, the lightweight nature of the material allows the chassis to react significantly faster and to respond more sensitively. The axle design bears the signature of experienced racing car developers, with double wishbone suspension at the front and rear. The lower struts are arranged so that, as the springs compress and when cornering at speed, the wheels have a negative camber. This ensures the best possible contact with the road in every situation. At the same time the axle technology prevents the front of the car from diving when braking heavily and the rear from diving when accelerating. Springing/damping combinations at the front and rear axle and a stabiliser at the front complete the chassis structure. The stabiliser is positioned above the front axle and as in Formula 1 is controlled via rocker arms.
The speed-sensitive rack-and-pinion power steering also corresponds with the intelli-gent lightweight concept. In comparison with other steering systems, this design is characterised by a significantly lower weight. Thanks to its low installation position in front of the engine and the gear ratio of 12.6, the steering system responds directly to the driver's commands and carries them out with high precision.
The electrohydraulic braking system, Sensotronic Brake Control (SBC), a milestone in car technology, forms part of the standard equipment of the Mercedes-Benz SLR McLaren. It processes data from various sensors regarding the current status of the vehicle and can use this to calculate and apportion the optimum brake pressure for each wheel at lightning speed. Mercedes-Benz has optimised the outstanding properties of the Sensotronic Brake Control system in the new SLR with a braking system which also marks a technological high-point in a high-performance car: at the front and rear axle of the cutting-edge swing-wing door vehicle, brake discs made from fibre-reinforced ceramic ensure reliable deceleration.
At the rear of the SLR an adaptive spoiler provides additional downforce. From a speed of 95 km/h, it automatically adopts a 10-degree position, increasing the contact pressure at the rear axle. The spoiler also doubles as an airbrake: when the driver brakes heavily, it rises to an angle of 65 degrees, not only ensuring increased aerodynamic drag but also shifting the aerodynamic centre further towards the rear.
Equipped with cutting-edge race car technology and ground-breaking new Mercedes developments, designed to ensure a high standard of safety and suitability for day-to-day use, the new SLR creates a distinctive image for itself as a 21st-century Gran Turismo a thrilling synthesis of tradition and innovation.
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