History
The Mercedes-Benz SLR McLaren is 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 will cease production of the SLR. The last of the coupes rolled off the production line at the end of 2007 and the roadster version is due to be discontinued in early 2009.Brakes
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 (14.6 in) in diameter. 8 piston calipers are used. Rear discs are 360 mm (14.2 in) in diameter with 4 piston calipers. During wet conditions the calipers automatically skim the surface of the discs to keep them dry.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 ~25%.
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.Engine
The SLR sports a 232 kg (171 lb·ft) hand-built 5.4-litre (5,439 cc (332 cu in)), supercharged, all-aluminum, 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 produces 0.9 bar (13 psi) of boost, the turbine rotates at 23000 revolutions per minute, and the air is cooled via two intercoolers. The engine generates a maximum power of 460 kW (617 hp) at 6500 revolutions per minute and a maximum torque of 780 N·m (575 lb·ft) at 3250 revolutions per minute.[4]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.
Performance
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 1,768 kg (3,898 lb). The following tests have proven that the SLR can achieve a 0-100 km/h (62 mph) in times less than the claimed 3.8 seconds and reach a top speed of 334 km/h (208 mph)[5].Car and Driver achieved a 0-60 mph (100 km/h) time of 3.6 seconds, and a quarter-mile time of 11.6 seconds at 125 mph (201 km/h) C&D suggests the times may be even lower if temperatures were lower. 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 0.97 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 3.5 seconds. The 0 - 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).
In June 2004 the SLR was tested at Nardo and performed the 0-100 km/h (62 mph) exercise in 3.8 seconds, 0-200 km/h (124 mph) in 11.5 seconds and 0-300 km/h (186 mph) in 30.4 seconds.[citation needed] Their 400 meter and kilometer times were 11.5 seconds at 122 mph (196 km/h) and 20.6 seconds at 278 km/h (173 mph) respectively. They also reached its claimed topspeed 334 km/h (208 mph).
Comparison
Despite its near 2-ton weight, the fuel economy is generally better than the lighter Lamborghini Murciélago, and even its lighter, less expensive, less powerful sibling, Gallardo.[6] Still, on the Episode 1 from Season 11 of BBC car show Top Gear the Lamborghini Murciélago performed better than the SLR during a race on the track. Also, the same show put the SLR and the Porsche Carrera GT on its track, and after multiple attempts, the Porsche beat the SLR-McLaren by just over a second (1:19.8 vs. 1:20.9[7]). However, on a separate race around their short track, the SLR was fractionally quicker than the Carrera GT. In a straight line, the SLR is quicker throughout the range.
Variants
722 Edition
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" boosts power to 650 PS (478 kW; 641 hp) and 820 N·m (605 lb·ft) of torque at 4000 rpm, posting a top speed of 337 km/h (209 mph) (just 3 km/h faster than the standard SLR). 19-inch light-alloy wheels were used to reduce unsprung weight, while modifications were also made to the suspension, with a stiffer damper setup and 10 mm (0.4 in) lower ride height introduced for improved handling. Larger 390 mm (15.4 in) diameter front brakes and a revised front air dam and rear diffuser were fitted.[8]
Exterior changes, other than the larger 19-inch (480 mm) black light-alloy wheels, include red "722" badging, hearkening back to the original 722 racer.
The SLR 722 can go from 0 to 100 km/h (62 mph) km/h in 3.6 seconds, 200 km/h (124 mph) in 10.2 seconds and 300 km/h (186 mph) in 21.4 seconds and can reach a top speed of 337 km/h (209 mph).
Roadster
A roadster version of the SLR went on sale in September 2007 for £350,000 ($711,065 U.S.). 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 332 km/h (206 mph) and enable 0-100 km/h dash time of 3.8 seconds.[9] However, being a convertible the roadster will have to be burdened with extra weight and this will affect performance and handling. The Roadster's roof, however, is made from a "newly developed material" and hence will not take the form of a folding metal arrangement, as is now common on many modern cars. Following a manual unlatching, it takes a mere 10 seconds to fold away electrically. According to an official document from Mercedes, the cabin of the roadster is capable of allowing conversation between driver and passenger up to a speed of 124 mph (200 km/h) with the roof retracted. It is unsure if McLaren will release another version of the roadster like it did with the SLR 722 version. This roadster is aimed to compete against other sports cars such as the Pagani Zonda F Roadster.[10]722 GT
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 inch 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 and reduced its dry weight to 1,300 kg (2,866 lb) . The engine remains in relatively stock specification but now produces 680 PS (500 kW; 671 hp) and 830 N·m (612 lb·ft) at 1.75 bar (175 kPa) boost. Inside, the car is stripped out with only the essential functions being controlled from a carbon fiber binnacle. New carbon fiber 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, for €795,000 (1.2 million USD).[11]
Stirling Moss
To conclude its collaboration with McLaren, Mercedes Benz released a speedster edition of the SLR, named SLR Stirling Moss, with production from July to December 2009. Inspired by the legendary 300 SLR, the Stirling Moss will have gullwing doors, no roof and no windows. The car will be approximately 200 kg (440 lb) lighter than the regular model. The top speed is higher than the standard car at 217 mph and will go from 0-60 in 3.5 seconds. The production run is limited to 75 pieces.[12]sumber: http://en.wikipedia.org/wiki/Mercedes-Benz_SLR_McLaren
0 comments:
Post a Comment