Mercedes-Benz SLR McLaren

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Mercedes-Benz SLR McLaren

Manufacturer	McLaren Automotive
Production	2003–2010
Assembly	Woking, Surrey, England, UK
Successor	Mercedes-Benz SLS AMG
Class	Grand tourer
Body style(s)	2-door coupé 2-door roadster
Layout	Front mid-engine, rear-wheel drive
Engine(s)	5.4 L supercharged V8 (M115 ML55)
Transmission(s)	5-speed automatic
Wheelbase	2,700 mm (110 in)
Length	4,656 mm (183.3 in)
Width	1,908.5 mm (75.14 in)
Height	1,261 mm (49.6 in) 2006–08: 1,252 mm (49.3 in)
Curb weight	1,768 kg (3,900 lb)

The Mercedes-Benz SLR McLaren is an Anglo-German grand tourer jointly developed by Mercedes-Benz and McLaren Automotive, built in Portsmouth and the McLaren Technology Centre in Woking, Surrey, England. At the time Mercedes-Benz owned 40 percent of the McLaren Group.
Due to the presence of the automatic gear box, front mid-engined arrangement, and its driving characteristics, some commentators classify the SLR McLaren as a GT whose rivals would be vehicles like the Aston Martin DBS V12 and Ferrari 599 GTB Fiorano.
SLR stands for "Sport, Leicht, Rennsport" (sport, light, racing). Mercedes-Benz stated that they would build 3,500 SLRs over a span of seven years, with an annual production of 500 cars.^[1] The car's base price, GB£295,337 (approx. US$450,000, €351,269, CHF 500,000 or C$ 499,999c. 2009),^[2] made it the ninth most expensive street legal car in the year 2008.^[3]

History

The Mercedes-Benz SLR McLaren was inspired by the Mercedes-Benz 300 SLR of 1955, based on the W196 F1 car, yet named after the road-going 300SL Gullwing. On 4 April 2008, Mercedes announced they would cease production of the SLR. The last of the coupes rolled off the production line at the end of 2007 and the roadster version was discontinued in early 2009.

Technical highlights

Brakes

The SLR features Sensotronic, a type of brake-by-wire system.^[4] The brake discs are carbon-ceramic and provide better stopping power and fade resistance than steel discs when operating under ideal working temperature. Mercedes-Benz claims these discs are fade resistant to 1,200 °C (2,200 °F). The front discs are internally vented and 370 mm (15 in) in diameter. 8 piston calipers are used. Rear discs are 360 mm (14 in) in diameter with 4 piston calipers. During wet conditions the calipers automatically skim the surface of the discs to keep them dry.

Rear view of the SLR McLaren Roadster

To improve braking performance there is an automatic air brake, when engaged the rear elevation angle of the rear spoiler is set to 65 degrees. The additional rear downforce in addition to the markedly increased aerodynamic drag increases peak deceleration ~90%.

[edit] Aerodynamics

The SLR features active aerodynamics; there is a spoiler mounted on the rear integral air brake flap. The spoiler increases downforce depending on its angle of elevation (angle of attack). At speeds above 95 km/h (59 mph) the spoiler/brake automatically raises to 10 degrees (15 in 722 edition), when demanded via the driver's switch, the elevation can be increased to 30 degrees (35 in 722 version) for increased rear downforce, at the cost of increased steady state drag, also when the driver applies the brakes the spoiler raises.However if the driver does not apply the brakes the spoiler will not raise.

Engine

The SLR McLaren sports a hand-built 5.4-litre, supercharged V8 engine.

The SLR sports a 232 kg (510 lb) hand-built 5,439 cc (5.439 L; 331.9 cu in), supercharged, all-aluminium, SOHC V8 engine. The cylinders are angled at 90 degrees with three valves per cylinder and lubricated via a dry sump system. The compression ratio is 8.8:1 and the bore and stroke is 97 millimetre (3.82 in) and 92 millimeters (3.62 in), respectively. The Lysholm-type twin-screw supercharger rotates at 23000 revolutions per minute and produces 0.9 bar (13 psi) of boost. The compressed air is then cooled via two intercoolers. The engine generates a maximum power of 626 PS (460 kW; 617 hp)@6500rpm and maximum torque of 780 N·m (580 lb·ft)@3250-5000rpm.^[5]
Unlike most of its contemporaries, its engine is front-mid mounted. McLaren took the original concept car designed by Mercedes and moved the engine 1 metre (39.4 in) behind the front bumper, and around 50 centimetres (19.7 in) behind the front axle. They also optimized the design of the center firewall.

Transmission

The SLR uses AMG SPEEDSHIFT R 5-speed automatic transmission with 3 manual modes. For durability Mercedes selected a 5-speed transmission rather than their 7-speed gearbox which was more complex and used more parts.

] Performance

A Mercedes-Benz SLR in motion

	Mercedes-Benz SLR McLaren 722 Mercedes-Benz SLR McLaren 722 at Goodwood Festival of Speed 2009
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The car uses carbon fibre for its entire body construction in an attempt to keep the weight low. Despite CFRP materials the total curb weight is 1,750 kg (3,858 lb). McLaren claims a 0-100 km/h (62 mph) of 3.8, with a top speed of 334 km/h (208 mph)^[6].
Car and Driver achieved a 0-60 mph (100 km/h) time of 3.4 seconds, and a quarter-mile time of 11.2 seconds at 130 mph (209 km/h) C&D suggests the times may be even lower if temperatures were lower. Motor Trend tested the SLR and achieved a 0-60 mph time of 3.3 seconds in April 2006. Car and Driver achieved top gear acceleration 30-50 mph and 50-70 mph times of 1.7 and 2.4 seconds, which are the fastest ever recorded by the magazine in a production car. The SLR also pulled 1.13 g on the skidpad.January 2005
Road and Track tested the car in their July 2005 Road Test and reached 60 mph (97 km/h) from a standstill in 3.4 seconds. The 0 - 100 mph (160 km/h) sprint was achieved in 6.6 seconds and a quarter mile run was completed in 11.1 seconds at 132 mph (212 km/h).
In June 2004 the SLR was tested at Nardo and performed the 0-100 km/h (62 mph) exercise in 3.2 seconds, 0-200 km/h (124 mph) in 9.6 seconds and 0-300 km/h (190 mph) in 24.8 seconds.^{[citation needed]} Their 400 m (0.25 mi) time of 11.0 seconds at 133 mph (214 km/h) and 1 km (0.62 mi) time of 19.2 seconds at 282 km/h (175 mph) respectively. They also broke its claimed top speed of 334 km/h by reaching 339 km/h (211 mph).