|Porsche 909 Bergspyder|
The fierce rivalry between Porsche and Ferrari has its roots in the 1960s. Even though the two companies founded at about the same time and competed in many of the same races during the 1950s, they rarely crossed swords. It was only when Porsches started to vie for outright victories that the two legendary manufacturers became direct competitors.
The epic fight between the Ferrari 512s and Porsche 917s in the 1970 and 1971 editions of the 24 Hours of Le Mans is well documented. These firmly established Porsche as the new dominant force in endurance racing, a position Ferrari held for nearly two decades.
Ironically it was a fight between the two that did not take place, which resulted in one of the most extreme competition Porsches ever built. Known as the 909 Bergspyder (berg is German for mountain), it was constructed specifically for the 1968 edition of the much coveted European Hillclimb Championship.
Late in 1967 Ferrari had announced and even tested a purpose-built hillclimb racer. Powered by a Formula 1 derived flat-12 engine, it could be a very serious challenger for Porsche in the prestigious hillclimb championship.
In previous years Porsche used adapted versions of the latest sports prototypes but the company's development chief Ferdinand Piech feared that this approach would not suffice against the new Ferrari. The grandson of Ferdinand Porsche, commissioned the construction of, very literally, a no-compromise racing car.
From the start of the 1967 season the European Championship was disputed under Group 7 regulations. These stipulate mandatory road car equipment like fenders and two seats but no minimum weight. The ferocious Can-Am cars were built following the exact same rulebook. The one major difference was a 2-litre displacement limit for the hillclimb cars.
Due to the nature of the sport this placed all emphasis on keeping the weight down. Based on the 910/8 sports racer, the first Porsche Group 7 hillclimb car already weighed 420 kg (926 lbs). Piech nevertheless believed he required an even lighter car to fend off the Ferrari.
It was Lotus' Colin Chapman who famously coined this phrase, but Porsche's engineers turned this into a science. During the 1960s few manufacturers could rival Porsche's knowledge of lightweight metals, alloys and glass-reinforced plastics.
Like its predecessors, the 909 Bergspyder used an aluminium spaceframe chassis. The exotic material titanium was used for various suspension components, including the four coil springs. The engineers even experimented with alloy steering arms but these proved too fragile. The disc brakes available underlined to which extremes Porsche was ready to go to get the desired results.
First used on the 910/8 Spyder, they were cast in the rare earth metal beryllium. One-fourth the weight of conventional cast iron discs, they resulted in a 14 kg (31 lbs) cut. The drawback was the steep price ($1000 per disc) and toxicity of the inevitable beryllium dust. As a result only five examples were available, usually fitted on the car of the fastest driver. The discs were chrome plated to contain the poisonous dust.
A unique feature of the 909 was the fuel tank. At 16 litre, it could hold just enough fuel for one run up and back down the mountain. All 1.7 kg (3.8 lbs) of the fuel pump were saved by using a nitrogen pressurised sphere. The 'Kugeltank' consisted of a titanium exterior shell with a rubber bladder inside, which contained the fuel. Before the start nitrogen was fed into the space between the shell and the bladder to get the pressure needed to send the fuel to the engine.
The one constant in the Porsche hillclimb program was the Type 771 engine. Developed in conjunction with the Type 753 Formula 1 engine in the early 1960s, the horizontally opposed eight cylinder engine gave Porsche the final push up the ranks.
Although it had twice as many cylinders as the four cylinder engines used before it, the Type 771 incorporated many of the same design ideas. Needless to say the engine was air-cooled with forced cooling provided by a fan mounted on top of the magnesium alloy crankcase. To further aid cooling, each bank featured four separate finned cylinders and heads.
Also typically Porsche were the shaft-driven overhead camshafts, originally developed by Ernst Fuhrmann for the four cylinder engines. The shafts were driven from the middle of the crankshaft at half speed through bevel gears. Fuhrmann's original design used a single shaft per bank but for the new eight cylinder engine two were used; one for each of the four camshafts. By placing the valves at a 90° angle, the largest valves possible could be fitted.
Each of these each eight-cylinder engines took a staggering 220 hours to build. Using four Weber carburettors, the Type 771 produced 210 bhp at its 1962 debut. By 1968 the Webers had been replaced by fuel injection, which saw the power rise to its ultimate figure of 275 bhp at 9200 rpm.
In 2 and 2.2 litre trim, the Type 771 propelled the Porsche works cars to many victories, including the manufacturer's maiden victory in the Daytona 24 Hours in 1968. Dan Gurney used the Type 753 engine to win the 1962 French Grand Prix; Porsche's first and only Formula 1 win as a manufacturer.
In addition to the extreme weight saving measures, the 909 Bergspyder's packaging also broke new ground. It was the first time the Porsche engineers could design a chassis to suit the particular needs of a hillclimb course. This resulted in a shorter wheelbase and wider tracks compared to its predecessors. The wheels were literally mounted on each of the four corners of the car.
The quest for the perfect weight - however little there was of it - balance, led to the engine being pushed very far forward. The specifically developed five-speed gearbox was mounted between the engine and the differential. This novel approach ensured that all the mass was held within the wheelbase. Over the next years, this configuration would become common practice.
With the engine mounted so far forward in the chassis, the space for the driver was heavily compromised. He was forced to sit virtually between the front wheels, with his feet well ahead of the axle. There was so little room up front that the anti-roll bar had to be mounted ahead of the dashboard, between the steering wheel and the instruments.
The fuel tank, dry-sump oil tank and oil cooler were all mounted on the left hand side of the engine. The space on the right was reserved for the electric systems and the battery. Copper was considered too heavy so for the entire wiring loom silver was used. Further weight was saved by using balsa wood for the ignition system's two ballast resistors.
The rolling chassis was very tightly wrapped in a fibreglass body that was not particularly pleasing to the eye. The round nose sported two circular holes to cool the front brakes. Small dive-plains were mounted on the edge of the nose and the rear end featured two small, adjustable wings.
The result of the laborious work was a car that weighed just 375 kg before adding fuel and driver. That was an improvement of 45 kg (99 lbs) over the previous year's car. Illustrative of his obsessive approach was the method by which Piech made sure that the mechanics had not used a single steel screw or nut; he went over the entire car with a magnet.
Two cars were completed but they were not ready in time for the start of the season. This proved to inconsequential as Gerhard Mitter more than held his own in the rebuilt 910/8s. The Ferrari threat proved hollow as nothing was seen or heard of the flat-12 engined special, at least in 1968.
Although Mitter had dominated the opening rounds of the championship, it was far from a happy campaign for Porsche. Mitter's team-mate Rolf Stommelen broke his arm when his 910/8 left the road and new signing Lodovico Scarfiotti fatally crashed at the same event. Remarkably the popular Italian was the first driver to die at the wheel of a Works Porsche. His death cast a deep shadow over the rest of the year.
With two of the seven rounds to go, the 909 Bergspyder finally made its debut at the Gaisberg climb. Mitter decided to carry on with the 910/8 and won both rounds. Stommelen used the much anticipated new car and finished third at its debut. He had suffered fuel-feed problems and a more conventional electric pump was fitted for the final climb at the legendary Mont Ventoux. It helped him secure second behind his team-mate.
With six wins out of seven attempts, Mitter won his third championship in a row. Despite his injury, Stommelen had secured enough points for second in the standings. With little more to prove, Porsche ended the hillclimb program. The 909 Bergspyder was not used again.
In Porsche's absence, the Ferrari 212E Montagna did make its belated appearance at the start of the 1969 season. Whether it would have been enough to take on the Porsche Works team, we will never know. What is irrefutable is the unbeaten winning record of the Ferrari that season, which showed Piech fears were certainly not unfounded.
With a third and second place finish the 909 Bergspyder had a brief and hardly convincing racing career. Many of the lessons learned during the car's development were applied to later and very successful Porsche racing cars. Particularly the 908/3 owes much to the innovations made on the 909. This compact machine was driven to victories in the World Championship on demanding tracks like the Nurburgring and the Targa Florio.
The 909 Bergspyder remains as one of the most extreme Porsches ever constructed. Many cars have since emerged from Weissach that were more powerful and inevitably much faster. Very few of these were however the result of such an obsessive approach.
Article by Wouter Melissen, last updated on May 18, 2012
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