Performance Under PressureMercedes-Benz Kompressor
- June 20, 2017
- Posted by CCW
Performance under pressure. Over the decades, the qualities of sportiness and performance have been associated with one particularly resonant name at Mercedes and Mercedes-Benz: Kompressor.
Origins in aircraft engine technology.
Sportiness has become epitomised in the brand name Mercedes, which the Daimler-Motoren-Gesellschaft (Daimler Motor Corporation) began using in 1902. At the turn of the 20th century, Emil Jellinek, the first major customer of Daimler automobiles, registered the vehicles for races in Nice under the pseudonym of “Mercédès”, the name of his daughter. The name of the race-winning cars was soon adopted as the new brand name.
The ‘Kompressor’, or supercharger technology which made the Mercedes models unique around 20 years later, was introduced by Paul Daimler, a son of the company’s founder Gottlieb Daimler. Since 1909, the Daimler-Motoren-Gesellschaft had also been building aircraft engines.
In 1918 they began to install Roots-type blowers – originally patented in the USA in 1860 to generate wind for blast furnaces – to compress the thin air at altitude and produce a combustible mixture for the engines. In 1919, Paul Daimler, in his role as a technical director at the company, began to test whether air compressors could also be used to increase the power output and elasticity of motor vehicle engines. Daimler showcased production-ready models at the Berlin motor show in September 1921.
Mercedes cars with supercharging compressors were already being put to the test in motor racing before the new models went into series production. In April 1922, Mercedes entered two models equipped with the new technology at Targa Florio, the challenging endurance race in Sicily. A six-cylinder Mercedes 28/95 hp – the top Mercedes model of the day dating back to 1914 – had been retrofitted with a compressor. Also on the starting grid were two completely new four-cylinder racing cars with 1.5-litre supercharged engines based on the standard passenger car unit and now capable of generating 65 hp. The photo shows one of the four-cylinder models, with drivers Paul Scheef and Jakob Krauss.
Four cylinders plus supercharger.
Series production of the first Mercedes models in which a supercharger forced compressed charge air into the carburettor began in 1922. Two models with four-cylinder engines were available: a 1.6-litre unit delivering up to 40 hp and a 2.6-litre engine with an output of up to 65 hp. A limited run of only 18 cars also included the particularly sporty 6/40/65 hp (the model designation shows the taxable horsepower as well as the actual power output without and with the supercharger).
Mercedes, or Mercedes-Benz after the merger in 1926, was the first brand of car anywhere in the world to use supercharged engines and has continued to apply the technology throughout two eras of the brand’s history. The potential of the 6/40/65 hp to perform successfully in motor racing was realised by Rudolf Caracciola. When this photo was taken in 1924 he was 23 years old and recording his first victories with the supercharged car.
Two-and-a-half years after the supercharged cars first went into production, Mercedes revamped its model range: production of the four-cylinder mid-range models was stopped and almost at the same time two newly developed six-cylinder cars were introduced into the higher and luxury segments. As the inflation of 1923 had seriously weakened the economy, these new model types were the only ones Mercedes would have on offer until the merger with Benz two years later.
The 15/70/100 hp model type had an engine capacity of four litres, while the 24/100/140 hp was powered by a unit with a capacity of 6.3 litres. A sporty variant of the larger model was developed with a shorter wheelbase in 1926. With a top speed of 145 km/h the K model (the K stands for “kurz”, the German word for short, not for “Kompressor”) was the fastest touring car in the world. It was also used in motor racing both by private and works drivers and was soon causing quite a stir.
The arrival of a legend.
The legendary supercharged sports cars of the Mercedes-Benz S series caused a real stir from 1927. The S for Sport says it all. With their 6.8-litre (increased to 7.1 litres from 1928) six-cylinder supercharged engines, these racing and touring cars were invincible at many racing events. But the model types S, SS (Super Sport, from 1928) and SSK (Super Sport Kurz, also from 1928) were not pure racing cars: they were actually a part of the official product range offered by Mercedes-Benz.
Though customers weren’t able to buy the performance-boosted racing models, they could still enjoy up to 200 hp of driving performance – quite a sensation in those days. Only the limited-edition 300 hp SSKL of 1931 was used exclusively for racing and not made available for general sale.
To many observers, the 500 K launched in 1934, and later superseded by the more powerful 540 K in 1936, is one of the most sublime models of the period – particularly the roadster variant. In 1934 there was a dividing of the ways between racing cars and customer vehicles. The Mercedes-Benz Silver Arrows began their triumphant dominance of Grand Prix racing in the 750-kilo category. Customers in search of a high-performance vehicle could buy an eight-cylinder supercharged 500 K with a 5-litre engine capable of generating up to 160 hp.
The model was initially launched as the “500 with compressor”. The additional description was needed because Mercedes-Benz also had a “500 Nürburg” in its range (without a compressor). Adding the letter K to the name made the distinction clear and its use became official with the launch of the successor model, the 540 K (5.4-litre engine, up to 180 hp). With these two models the K now stood for “Kompressor”; previously it had only been used to denote models with the short (“kurz”) wheelbase.
Where state vehicles are concerned it’s unusual to talk about performance. It’s something you take for granted. This is also true for the 770 model type launched in 1930 and known as the “Grand Mercedes”. The carriage of choice for heads of government and captains of industry is one of the supercharged models that have made a lasting contribution to the reputation of the Mercedes-Benz brand. Although the 7.7-litre eight-cylinder engine of the 770 (W07) model type was in fact also available without a supercharger from 1930 to 1938, only around ten per cent of customers opted for that variant. The successor, launched in 1938 with the same name (W150), was only available with the supercharged engine delivering up to 230 hp.
The outbreak of the Second World War brought an end to the further development of supercharged cars at Mercedes-Benz. The last type 770 vehicles were produced in 1943. Only a few prototypes were made in 1941 of the limo with a 6-litre, V12 engine (W157), shown here as a design model. Only a few prototypes were made in 1941 of the limo with a 6-litre V12 engine (W157), shown here as a design model. This model and a variant with a shorter wheelbase were being developed to succeed the 770 and 540 K model types.
New beginnings: the C-Class and SLK, openings at AMG.
Over 50 years later a Mercedes-Benz model once again bore the legendary “Kompressor” badge, clearly visible and written in full on the boot lid. In September 1995 Mercedes-Benz updated the C-Class 202 model series, causing something of a stir with its supercharged model type, the 230 Kompressor. It was manufactured with one eye already on the compact Mercedes-Benz SLK roadster, which would be launched six months later. At the same time, a smaller two-litre supercharged engine went into production, initially for models for export and later used in all markets
By contrast to the traditional supercharger, the technology was now applied to give smaller capacity four-cylinder engines greater torque over a wider engine speed range and therefore an even delivery of power. The aim was to produce no negative impact on fuel consumption and emissions despite the higher power output. The supercharger design was a success and was used in the C-Class model series 202, 203 and 204, the SLK 170 and 171, the E-Class 210 and 211 and the CLK 208 and 209.
Into the new millennium as before, Mercedes-Benz compressor technology continued to pursue the aim of making large-volume engines even more powerful. AMG, which has been a member of the Daimler Group since 1999 as Mercedes-AMG GmbH, offered a number of Mercedes-Benz models under the “55 AMG” label with supercharged 5.5-litre V8 engines generating around 500 hp of power. The last AMG supercharged model was the G 55 AMG, which was available until 2012. Since then, Mercedes-Benz and Mercedes-AMG have turned to the more efficient turbocharger technology where increased power output is desired, and this has superseded the supercharger since 2011.
Report by mercedes-benz.com