The story begins in Detroit, at the North American International Auto Show 1999, where Mercedes-Benz presented the Vision SLR concept, which was inspired by the 300 SLR Uhlenhaut Coupé from 1955. Presented as “Tomorrow’s Silver Arrow”, based on the nickname of The already mentioned racing car, which was driven by drivers such as Sir Stirling Moss or Juan Manuel Fangio, met with a positive response from the public, so that a few months later the car manufacturer launched a roadster Version and finally decided to continue to start limited production.
At the time, Mercedes owned 40% of the McLaren Group, a partnership in which the two companies won the Formula 1 constructors ‘and drivers’ championships in 1998 and 1999, so the British manufacturer also took part in the SLR project.
Under the direction of the design team of McLaren F1 creator Gordon Murray, the Vision SLR has been extensively redesigned to be more aerodynamically efficient and technologically advanced.
The power plant was the brainchild of the experts from AMG. It started as a 5.4 liter M113 K V8 with slight modifications to the concept vehicles and was extensively improved for the final production versions and received the M155 SLR engine code.
It retained the all-aluminum construction, displacement and SOHC Three-valve-per-cylinder configuration of the unit that powers the 55 AMG performance flagships at the time, but has many exclusive upgrades. Most noticeable is the heavily reinforced closed-deck engine block, which was fundamentally different from the open-deck design of the M113 K. In addition, the compression ratio has been slightly reduced from 9: 1 to 8.8: 1 thanks to newly designed forged pistons and high strength forged connecting rods. The speed limit has also been improved to 7,000 rpm compared to 6,500 rpm.
Other notable improvements included more aggressive camshafts, an optimized exhaust system, a larger 80 mm (3.14 inch) throttle body or a dry sump lubrication system. Combined with the engine’s inherently compact size, the latter allowed Murray and his team to mount it in a lower position entirely behind the front axle, greatly improving weight distribution and balance.
The twin screw compressor of the Lysholm type was optimized for a maximum speed of 23,000 rpm and generated a boost pressure of 13 psi (0.9 bar). The compressed air was then cooled by two large charge air coolers, each with its own water pump.
With all of these upgrades, the M155 SLR produced 617 hp (460 kW) and 780 Nm of torque, which is sent to the rear wheels via an AMG SPEEDSHIFT R five-speed automatic, a version of the 5G-Tronic transmission from Mercedes specially built for this exclusive Grand Tourer.
After four years of hard development work, the series-ready Mercedes-Benz SLR McLaren was presented on November 17, 2003, followed by the 2006 722 Edition, an enhanced 641 hp version, the Stirling Moss’ 1955 Mille Miglia-winning 300-honored SLR. A year later, the SLR Roadster was presented together with the 722 S Edition.
The most exclusive and breathtaking version of the SLR was the Stirling Moss presented at the North American International Auto Show 2009. The speedster was designed by the Korean designer Yoon Il-hun and was the ultimate homage to the legendary British driver. It featured the most powerful iteration of the M155 SLR engine, which developed 651 hp (485 kW) and accelerated the car from standstill to 100 km / h in 3 seconds. It was produced in 75 units and was only available to existing SLR owners at a cost of over $ 1,000,000.
This model also marked the end of SLR production after a total of 2,157 units, all assembled at McLaren’s Surrey plant in the UK.
While the Mercedes-Benz SLR McLaren became one of the most popular supercars of the 2000s, its bespoke, handcrafted AMG engine will be remembered as one of the best supercharged V8s ever developed in Europe, not to mention one of the most best sounding all the time.
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