- A coupé with the claim of the Mercedes-Benz S-Class
- Technical basis is the SL series R 107
- Sports versions win honours at many rallies and long-distance events
When the new touring sports car of the R 107 series was presented in April 1971, the issue of whether a new large Coupé should be developed at Mercedes-Benz still remained unanswered. Discussion centred on whether one should additionally, and in the near future, design a four-seater sports coupé based on the R 107 series, or wait for the coming S-Class (116 series) to build it on that basis. But in that case a production model would not have arrived until much later, in the mid-1970s.
Karl Wilfert, then the head of Body Design in Sindelfingen, developed – pretty much on his own authority – a Coupé based on the R 107 and presented it one day to the Board of Management as a “rough draft.” Rejected at first, Wilfert managed to push through his idea of a sports Coupé with the tenacity which was so characteristic of him.
And so six months after its premiere the SL Roadster was followed in October 1971 by a comfortable four-seater Sports Coupé, the 350 SLC, whose unconventional lines also found it many friends around the world in the course of the years. The series was given the internal designation C 107.
The open-top vehicles of the SL series as a basis
The technical basis was the SL series R 107. This touring sports car was a powerful, self-confident and representational open-top vehicle, which had additionally been equipped with an equally successful detachable Coupé roof by its designers. In addition to elegance and safety, the body also exuded safety, since the two-seater’s crash behaviour was already well ahead of its time.
The decision to manufacture the R 107 series (“R” as in Roadster instead of “W” as in Wagen = car) was taken by the Board of Management after intensive debates on 18 June 1968. At dispute was whether there should be a Targa-roof version, i.e., one with a removable roof panel, instead of the fabric-topped variant, because owing to higher safety standards alarming news was to be heard from the USA regarding the licensing of open-top cars. The head of development at the time, Hans Scherenberg, pushed through the decision to go ahead with an open-top two-seater with a fabric roof and an additional removable hardtop.
Up to the windscreen its appearance matches that of the open-top variant; behind the windscreen the overall height and length grows. A flat roof spans the four-seater passenger compartment in a gentle curve, going over into a large and very steep rear window that arches in two directions. The boot lid is slightly convex in shape, unlike that of the SL.
In the side view the length of the Coupé is documented, firstly, by the 360 mm (14 in) longer wheelbase (2820 mm/111 in versus 2460/104 in), secondly by the line of the side windows. Without awkward B-pillars they are completely retractable, as is usual in a Mercedes-Benz Coupé. The SLC’s coefficient of drag is better than that of the SL so that the Coupé attains the same performance despite an added weight of some 50 kilograms (110 lbs).
A particularly noteworthy fact is that it fully lived up to its classification as a “Sports Coupé,” gaining wins for Mercedes-Benz in many rallies and long-distance races.
Béla Barényi’s safety concept with front and rear crumple zones and a rigid passenger cell found expression in the 107 series in a further developed form. The backbone of the R 107 series is not simply a shortened and reinforced Saloon floor assembly, as in the predecessor, but an independent frame-floor unit with a closed transmission tunnel and box-shaped cross and longitudinal members which featured differing sheet metal thicknesses and a resultant carefully defined crumple pattern.
The SL definitely had to be an open-top car, and that being the case the only protection in a possible roll-over would be provided by the A-pillar plus windscreen. They were thoroughly redesigned and had 50 percent more strength to show than in the previously built version. In addition, to enhance its strength the windscreen was bonded into the frame. This resulted in a remarkable power of resistance in the roof-drop test with the result that the open-top car could be licensed for the USA even without a Targa bar. The SLC Coupé also benefited from this design.
In the interior the hard dashboard made way for an ingenious sheet-steel design that yields on impact both in the top section and the knee area and is foam-padded. The switches and levers were recessed. Another new feature: the four-spoke steering wheel based on the latest findings of accident researchers. The proven impact absorber was still in place, but the steering-wheel rim, spokes, padded boss and hub were covered with polyurethane foam. As further safety feature the fuel tank was no longer installed in the rear end but above the rear axle, protected against collision. The anti-lock braking system ABS was available from March 1980.
Like the Roadster, the Coupé met with a very favourable response. Its distinctive front end with the dominant SL face, the wide-band headlamps and grooved indicator covers had a powerful aura; the lines of the low silhouette were harmonious. The wide-band tail lights with their ribbed surface not only were largely insensitive to soiling, but additionally gave the rear end a touch of vigour.
A number of details underscored the car’s safety aspirations. The seats were available from the start with head restraints, and seat belts also were included. Physical well-being and driver-fitness safety were served by the heating system with its very spontaneous response, supported by new air ducting at the doors. Newly developed wind-deflecting mouldings on the A-pillars, which also served to channel off mud-laden water in the rain, and dirt-repelling covers on the exterior mirrors enabled good visibility. They kept the side windows clean even in inclement weather. The windscreen wipers arranged closely to each other in the centre of the car swept a respectable 70 percent of the windscreen area, were always optimally positioned in the flow of air and did not lift off even at higher speeds.