Mercedes-Benz SLR McLaren

The Mercedes-Benz SLR McLaren (C199 / R199 / Z199) is a grand tourer car jointly developed by Mercedes-Benz and McLaren Automotive, built in Portsmouth and the McLaren Technology Centre in Woking, Surrey, England and sold from 2003 to 2010. When it was developed, German manufacturer Mercedes-Benz owned 40 percent of the McLaren Group. SLR stands for "Sport Leicht Rennsport" (Sport Light Racing), homage to the Mercedes-Benz 300 SLR which served as the McLaren's inspiration. Both coupé and roadster versions were offered.

The SLR McLaren was succeeded by the Mercedes-Benz SLS AMG.

History
At the 1999 North American International Auto Show, Mercedes-Benz presented their Vision SLR concept, inspired both by the Mercedes-Benz 300 SLR Uhlenhaut Coupé of 1955, which was a modified Mercedes-Benz W196S race car, and the design of closed-wheel Formula One cars, a field in which Mercedes had prior experience, providing engines for McLaren bodies. The car was presented as "Tomorrow Silver Arrow" in a clear reference to the Silver Arrows of the golden age of Mercedes in competition during the fifties. Later that year, during the Frankfurt Motorshow it was presented the roadster version. The concept car was presented with an AMG 5.5 litre V8 engine supercharged with a mechanical compressor able to deliver 557 HP and 720 Nm at 4,000 rpm, mated with a 5-speed automatic gearbox with Touchshift control.

Wanting to bring the concept to production, Mercedes joined with their Formula One partner, McLaren, thus creating the Mercedes-Benz SLR McLaren. The final production model was presented on 17 November 2003 featuring some minor design adjustments respect the initial design, like a more complex vents in both sides, a redesign of the front part, with the three pointed star plunged in the nose and red tinted rear lights sets.

The Mercedes-Benz SLR McLaren saw a production run of over six years. On 4 April 2008, Mercedes announced it would discontinue the SLR. The last of the coupés rolled off the production line at the end of 2009 and the roadster version was dropped in early 2010. Due to the automatic gear box, front mid-engined arrangement, and its driving characteristics, some commentators classify the SLR McLaren as a GT, whose rivals would include vehicles such as the Aston Martin DBS V12 and Ferrari 599 GTB Fiorano.

Brakes
Mercedes-Benz SLR McLaren ->

The SLR features Sensotronic Brake Control, a type of brake-by-wire system. 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) diameter eight-piston calipers are used. Rear discs are 360 mm (14 in) in diameter with four-piston calipers. During wet conditions the calipers automatically skim the surface of the discs to keep them dry. To improve braking performance an automatic air brake deploys at a 65 degree angle at high speed.

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 a set speed, the spoiler/brake automatically raises to 10 degrees (15 degrees in the 722 edition), when demanded via the driver's switch, the elevation can be increased to 30 degrees (35 degrees in the 722 edition) for increased rear downforce, at the cost of increased steady state drag.

Engine
The SLR McLaren sports a hand-built 5.4-litre, supercharged 626 PS all-aluminum V8 engine

The SLR sports a 232 kg (511 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 mm × 92 mm (3.8 in × 3.6 in). The Lysholm-type twin-screw supercharger rotates at a maximum of 23,000 rpm 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) at 6,500 rpm and maximum torque of 780 N⋅m (580 lb⋅ft) at 3,250 to 5,000 rpm.

The 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 optimised the design of the centre firewall.

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

Performance
The car uses carbon fibre reinforced plastics (CFRP) construction in an attempt to keep the weight low. Despite CFRP materials the total curb weight is 1,750 kg (3,858 lb).

Car and Driver achieved a 0 to 60 mph (97 km/h) time of 3.4 seconds, and a quarter-mile time of 11.2 seconds at 130 mph (210 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 (48-80 km/h) and 50-70 mph (80-113 km/h) 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.

Road and Track tested the car in their July 2005 Road Test and reached 60 mph (97 km/h) from a standstill in 3.5 seconds. The 0 to 100 mph (160 km/h) sprint was achieved in 7.5 seconds and a quarter mile run was completed in 11.5 seconds at 126 mph (203 km/h).

722 Edition
Mercedes-Benz SLR Mclaren 722 Coupe >

A new version was introduced in 2006, called the Mercedes-Benz SLR McLaren 722 Edition. The "722" refers to the victory by Stirling Moss and his co-driver Denis Jenkinson in a Mercedes-Benz 300 SLR with the starting number 722 (indicating a start time of 7:22 a.m.) at the Mille Miglia in 1955.

The "722 Edition" includes an engine rated 650 PS (480 kW; 640 hp) at 6,500 rpm and 820 N⋅m (600 lb⋅ft) at 4,000 rpm. 19-inch light-alloy wheels were used to reduce unsprung mass, while modifications were also made to the suspension, with a stiffer damper setup and 10 mm (0.39 in) lower ride height introduced for improved handling. Larger 390 mm (15 in) diameter front brakes and a revised front air dam and rear diffuser were fitted.

Exterior changes, other than the larger 19-inch (480 mm) black light-alloy wheels, include red "722" badging, harking back to the original 722 racer, and slightly different tail lights and headlamps.

The SLR 722 can accelerate from 0 to 100 km/h (62 mph) in 3.6 seconds, 200 km/h (124 mph) in 10.2 seconds and 300 km/h (186 mph) in 27.6 seconds, and can reach a top speed of 337 km/h (209 mph) faster than the standard Mercedes-Benz SLR McLaren.

Roadster
Mercedes-Benz SLR Mclaren 722 Roadster > A roadster version of the SLR went on sale in September 2007. It uses the same supercharged V8 AMG power plant as its coupé siblings, developing 626 PS (460 kW; 617 hp), to propel it to a top speed of 334 km/h (208 mph) and a 0 to 100 km/h (62 mph) acceleration time of 3.1 seconds.

However, as a convertible the roadster was burdened with extra weight, which affected performance and handling. The Roadster's roof is made from a "newly developed material" and does not take the form of a  folding metal arrangement, as is common on many modern cars. Following a manual unlatching, it takes ten seconds to fold away electrically. According to an official Mercedes document, the cabin of the roadster is capable of allowing conversation between driver and passenger up to a speed of 200 km/h (120 mph) with the roof retracted. This roadster is aimed to compete against other sports cars such as the Pagani Zonda F Roadster.

Roadster 722 S (2009)
Mercedes-Benz SLR Mclaren 722 S > A limited edition (150 units) of the 722 coupé. It can reach 100 km/h (62 mph) from standstill in 3.6 seconds and has top speed of 334 km/h (208 mph). The model went on sale in January 2009.

722 GT (2007-)
One of 21 SLR 722 GTs at the Goodwood Festival of Speed

The 722 GT is a tuned version of the SLR 722 which is developed for a one-make racing series. The cars are built by Ray Mallock Ltd. with approval from Mercedes-Benz. The car features new wider bodywork to accommodate 19 in (483 mm) OZ racing wheels. The front grill vents are removed and larger, free flowing air extractors sit on the hood and flank the side of the car. The rear now has a racing wing and diffuser.

Under the body, the car has shed 398 kg (877 lb) and reduced its dry weight to 1,300 kg (2,900 lb). The engine remains in relatively stock specification but now produces 690 PS (510 kW; 680 hp) and 868 N⋅m (640 lb⋅ft) at 1.75 bar (175 kPa) boost. Inside, the car is stripped out with only the essential functions being available, controlled from a carbon fibre binnacle. New carbon fibre door panels and full roll cage complete the transformation.

RENNtech announced 21 SLR McLaren 722 GT would be available to the North American market exclusively through RENNtech.

Stirling Moss (2009)
Mercedes-Benz SLR Stirling Moss -->

Named after the British racing driver of the same name, the SLR Stirling Moss is a limited edition (75 vehicles) of the series, which uses a speedster styling that does not include roof or windscreen. The design is inspired by the 300 SLR race car, and the exterior was designed by Korean designer Yoon Il-hun, the interior by Dutch designer Sarkis Benliyan. It was to be the last series of the McLaren SLR built under the partnership between Mercedes-Benz and McLaren, until McLaren announced their own final edition of the SLR in late 2010.

The supercharged V8 engine is rated 650 PS (480 kW; 640 hp). The car's top speed is 350 km/h (220 mph) with acceleration from 0 to 100 km/h in less than 3.5 seconds. The car is approximately 200 kg (440 lb) lighter than the regular model.

The SLR Stirling Moss began production in June 2009, after SLR Roadster's production ended in May 2009. All 75 cars were produced by December 2009. The SLR Stirling Moss was available only to SLR owners.

The vehicle was unveiled at the 2009 NAIAS.

McLaren Edition (2011)
In December 2010, more than a year after the SLR was discontinued, McLaren announced a final body conversion of the supercar. The 25-unit limited McLaren Edition is based on any earlier variant of the SLR besides the Stirling Moss and includes revised bodywork (front and rear bumper, grille, top shell, side grills, rear diffuser, rims) and interior parts, along with upgraded steering and suspension components and a new sports exhaust.

Sales
Total sales were 615 units in 2005, 261 units in 2006, and 275 units in 2007, falling well below Mercedes-McLaren's goal of selling 500 units annually.

When the SLR was first announced, Mercedes said total production would be limited to 3500 units. 1400 units had been sold by the end of 2007. The factory confirmed that production would halt at the end of 2009.

A total of 2,157 SLR McLaren's were produced.

Motorsports
Spencer Pumpelly entered an SLR McLaren in the Speed World Challenge GT class, driving for TRG Motorsports.