General Information |
Vehicle Type: |
2-door convertible, race car |
Price: |
$---,--- |
Miles Per Gallon: |
--/-- mpg |
Drivetrain |
Configuration |
Front Engine/RWD |
Engine: |
Inline-8 |
Displacement: |
2982 cc |
Horsepower: |
310 bhp @ 7400 rpm |
Torque: |
234 lb-ft @ 5950 rpm |
Max RPM: |
7800 rpm |
Transmission: |
5-Speed Manual |
Dimensions |
Weight: |
1986 lbs |
Height: |
43.3 in |
Length: |
169.3 in |
Width: |
68.5 in |
Wheelbase: |
93.3 in |
Track: |
f: 52.4 / r: 54.3 in |
Performance |
0-60 mph: |
-.- sec |
0-100 mph: |
--.- sec |
Quarter Mile: |
--.- sec @ --- mph |
Top Speed: |
186 mph |
Lateral Acceleration: |
.--g |
Braking, 60-0 mph: |
--- ft |
Slalom Speed: |
--.- mph |
Nürburgring Lap Time: |
--.- minutes |
|
Behind the development of the 300 SL between 1951 and 1954 and the construction of the successful 300 SLR racing sports car was the inspiration of a man who was to become known as the technical brains behind the Silver Arrows: Rudolf Uhlenhaut.
Uhlenhaut was an engineer with petrol in his blood, but was also a skilled driver. For example, during chassis testing with the Formula 1 racing car at Hockenheim in 1954, he bettered Fangio’s best time by 3.5 seconds. However, he never really considered driving in the races himself, instead preferring to direct operations behind the scenes. In addition to his specialist expertise, Uhlenhaut was frequently called on to display a well-honed talent for improvisation.
Development
The development of the racing sports car was heavily influenced by the Mercedes 300 SL with striking gullwing doors, which first lined up at the start of the Mille Miglia in 1952 and a road-going version of which made its debut in February 1954. It was this famous model which provided the basic concept for the new racer, featuring a lightweight but high-strength tubular steel frame supporting an aluminium body. However, the 300 SLR also stood out with a host of individual characteristics very much its own. These included a five-speed transmission, 16-inch wheels and larger brakes.
Above all, though, the racing sports car developed far greater output than its “little brother” the SL – an eight-cylinder engine with petrol direct injection and dual ignition, essentially the same unit which powered the 1954 Formula 1 racing car, saw to that. The “Monoposto” and “Stromlinie” open-top body variants of the W 196 R Silver Arrow had chalked up numerous victories in international events, including the French Grand Prix, the Nürburgring race, the Italian Grand Prix, the Avus race in Berlin and the Argentinean Grand Prix.
The displacement of the Formula 1 eight-cylinder power unit was increased from 2.5 litres to 3.0 litres for use in the 300 SLR racing sports car. This boosted out-put to as much as 310 hp at 7400 rpm, depending on the intake manifold. Maximum torque of 317 Newtonmetres at 5950 rpm ensured quite majestic pulling power. The hugely powerful engine was mounted longitudinally in the front section of the car at an angle of 33 degrees and supplied with a high-octane fuel mixture of low-lead petrol (65 percent) and benzol (35 percent). In some races, alcohol was also used to push performance up to even greater heights. As a rule, the racing sports car roared off the starting line with 167 litres of fuel and 35 litres of oil on board. However, Moss and Jenkinson began their assault on the 1955 Mille Miglia with as much as 265 litres of fuel in the tank.
The Stuttgart-based engineers organised a series of uncompromising test runs in order to establish the durability of the eight-cylinder unit. It was put through its paces over a distance of more than 10,000 kilometres at race speed, before being subjected to a 32-hour non-stop test rig examination. These were merciless tests of endurance, but they were still not enough to break the W 196 S engine.
The Air Brake
In addition to an anti-lock braking aid designed for emergency situations – which worked by injecting oil onto the surface of the brakes – and the hydraulic brake booster, Mercedes-Benz started the Le Mans 24-hour race in June 1955 with an ingenious piece of technology in tow. An air brake fitted to the rear of the 300 SLR could be raised using a hydraulic pump. With a surface area of 0.7 square metres, the light-alloy wing had a significant braking effect as well as enhancing the car’s handling around corners.
The idea for this “wind brake” was dreamt up by director of motorsport Alfred Neubauer, who was looking to develop an assistance system to help take the strain off the wheel brakes and tyres during endurance tests such as the races at Le Mans and Reims. Neubauer wanted to use the decelerating properties of the car’s aerodynamics at Le Mans in particular, as the French track forced the drivers hard onto the brakes lap after lap in order to bring the car down from its maximum speed to as little as 40 km/h.
Mercedes-Benz enjoyed incredible success in 1955, but the brand’s winning run was overshadowed mid-way through the season by a tragic accident during the Le Mans 24-hour race. Forced off the track as it approached the pit lane, one of the 300 SLR racing sports cars was unable to stop and careered into a spectator grandstand. In all, 81 people were killed in what was an appalling disaster. Mercedes-Benz immediately called all its cars into the pits and retired them from the race.
The SLR racing sports cars lined up again at the start of the last major race of the 1955 season, the Swedish Grand Prix. And the head-turning air brake was to prove its value once again. Juan Manuel Fangio took the chequered flag with an average speed of 161 km/h.
The End of a Legend
Uhlenhaut’s plans to build on the success of the 300 SLR in 1955 with the coupé version the following year were to hit the buffers: in October 1955, shortly after Stirling Moss/Peter Collins and Juan Manuel Fangio/Karl Kling had completed a one-two victory in the season-ending Targa Florio, the Daimler-Benz Board of Management took the decision to withdraw from motor racing. There had certainly been no plans to bow out with the brand at the peak of its powers, but circumstances dictated that there was no other reasonable course of action. The Mexican government had cancelled the 1956 Carrera Panamericana for safety reasons, and the shock of the Le Mans tragedy of June 11, 1955 was still very keenly felt. A period of reflection away from the motorsport hot-house therefore appeared to be the best move at the time. Nobody could have imagined for a second that it would be decades before Mercedes eventually made a return to the track.
Rudolf Uhlenhaut refused to express his personal disillusionment with the absence of his company from international motor racing, presenting instead a typically resolute public face. However, saving his Coupé from the ravages of time was beyond even him – Mercedes’ motorsport comeback was just too far away. In 1959 Uhlenhaut took over as the head of passenger-car development at Mercedes-Benz and continued to define the technology and character of the brand’s cars until his retirement in 1972. Rudolf Uhlenhaut died on May 8, 1989 just short of his 83rd birthday.
Uhlenhaut’s legacy will live on into eternity. As the technical inspiration behind the Formula 1 Silver Arrows and the SLR racing sports car, as well as the creator of the 300 SL Gullwing, he has gifted a global army of fans some very special cars. The “Uhlenhaut Coupé” of 1955 was without doubt one of the outstanding super sports cars ever produced by Mercedes-Benz. For experts and motor racing enthusiasts alike, its name is a byword for all-round technical genius, driving pleasure and reliability.