Unique Porsche 917 K81 taken from museum to be returned to 24 Hours of Le Mans years later.
Porsche 917 K81, the latest modification of the legendary racing prototype, was exhibited at the Retro Mobile Motor Show in Paris. The 917 won the 24 Hours of Le Mans twice, in 1970 and 1971, but the 1981 version built by the Kremer team was not successful. But still it is a historically valuable car – and it is now for sale.
French exotic and racing car dealer Ascott Collection has brought a Porsche 917 K81 racing car to the Retromobile showroom in Paris. We decided to tell you about the intricate fate of this unique car.
Living legend
The Porsche 917 itself is a true motorsport legend. Sports prototypes with a 12-cylinder engine from 1969 to 1974 were noted with great success in long races around the world. During this time, factory and semi-factory team drivers won two 24 Hours of Le Mans and 24 Hours of Daytona, brought Porsche two titles in the World Championship for brands and two times became champions in the prestigious American Can Am series.
The development of the racing car was led by the legendary engineer Ferdinand Piech, who in those years headed the advanced development department at Porsche, and later became the head of the Volkswagen concern. In its original form, the Porsche 917 was a streamlined coupe with an aluminum or magnesium tube space frame and fiberglass exterior panels. But later, open modifications were created for the Interseries and Can Am races.
Destructive force
The main distinguishing feature of the entire 917 family was a huge 12-cylinder air-cooled boxer engine. Even the very first modifications of 4.5 liters developed 540 horsepower, but their power was quickly increased to 580 horsepower. The maximum speed even then, in 1969, was about 320 kilometers per hour! In the future, the working volume was increased to 4.9 liters, then to 5.0 and even 5.4 liters: in the last iteration, the “opposite” developed 660 forces.
The sports career of this supercar was extremely successful, but very short-lived. He made his debut in racing in 1969, and already at the end of the 1971 season, he was actually banned – in the 24 Hours of Le Mans, as in the entire World Championship for brands, the engine capacity was limited to three liters.
But this spurred the second career of the “nine hundred and seventeenth” – overseas. Especially for the American Can Am series, the Germans, together with the Penske team, redesigned the car, turning it into an open spider, and equipped the 12-cylinder engine with a turbocharger. It was one of the world’s first experiences with a turbo engine in motorsport – and extremely successful! George Vollmer took the title in 1972, Mark Donoghue in 1973. After that, the series was waiting for a quick decline, and the Porsche 917 was nicknamed “the car that killed Can-Am.”
What does “K” mean?
A few years later, German racing driver Erwin Kremer stumbled upon a Porsche 917 in the English Midlands Motor Museum, owned by the legendary Mexican sportsman Pedro Rodriguez. The Kremer Racing team he and his brother Manfred owned successfully raced Porsches, mostly in their own turbocharged 935 coupe. The highest achievement was the victory at the 24 Hours of Le Mans in 1979.
Erwin Kremer had a plan: to bring the well-deserved sports car to modern standards – since the 12-cylinder engine remained powerful and reliable.
The fact is that in the early eighties, sports car racing was just entering a period of change. The three-liter cars of groups 5 and 6 were about to be banned, and the new group C sports prototypes were not yet ready. And to fill the resulting vacuum, the organizers of the 24 Hours of Le Mans introduced a new set of temporary technical requirements in 1981. The large-capacity motor from the Porsche 917 fit perfectly into them.
“For two years we were buying parts from a Porsche 917,” said Erwin Kremer, “and when we had enough, I contacted people from Porsche. They liked the idea, so they helped us with chassis drawings, buying additional parts, and building two motors for us.”
The Le Mans organizers from the ACO club were completely delighted: a shortage of participants was expected in the race, and here is a strong German team with a legendary car! The project was supported by a large real estate agency Malardeau, paying for the participation of two local riders – along with Bob Vollek, Guy Chassel and Xavier Lapeyre were supposed to go.
New wine in old wineskins
In the twelve years since the debut of the original Porsche 917, tire traction has improved a lot. Therefore, the new spatial frame was made much stronger, based on increased loads. The thicker tube frame with additional diagonal braces weighed 65 kilograms (+15 kg). But even with a stronger frame, the car remained light – 893 kilograms (the original Porsche 917 weighed from 850 to 900 kilograms). Powerful brakes borrowed from the Can Am series turbocharged spider. From him they took a gearbox with only four steps.
The aerodynamic design was completely redesigned: the clearance was reduced, instead of roundings along the bottom of the body, a pointed “skirt” was launched, and most importantly, a hefty wing was hoisted onto the engine compartment cover. In the classic “short-tailed” form, the Porsche 917 was not equipped with a full-size rear wing – however, it was installed on the streamlined 917 LH coupe and the turbocharged 917/10 and 917/30 Spyders of the American Can Am series. In the end, almost everything was redone. The car of the Kremer brothers retained only the doors and the windshield from the source – the rest of the details of the plumage were original.
A funny episode: on the eve of the race, the car had to be urgently redone. At the technical commission, it turned out that the coupe does not qualify for the GTP class in terms of the distance between the windshield pillars. Of course, there could be no talk of serious alterations. And then the car … was turned into an open spider of group 6. Of course, purely formally – for this it was enough to cut a narrow longitudinal slot in the roof.
At first, observers highly appreciated the potential of the car – they considered it almost the favorite of the race: a powerful and reliable engine, a chassis that had been worked out over the years, an experienced and competent team, an excellent pilot Bob Vollek spoke in its favor …
But everything turned out not so rosy at all. They simply didn’t have time to carry out any finishing work with the car – no tests on the race track, no tests in the wind tunnel. The car was presented to the public at the Nurburgring, just a few days before Le Mans.
And already in France it turned out that the car was sorely lacking in maximum speed. And this is on the Sarte ring, famous for its huge straights! Let me remind you that even the early versions of the Porsche 917 developed 320 kilometers per hour, and the streamlined “longtail” with a 4.9 engine in 1971 accelerated to 386 kilometers per hour. But the car of the Kremer brothers barely reached 300 kilometers per hour. For comparison: in the same 1981, the factory Porsche 936 spider produced up to 355 kilometers per hour.
According to estimates, the car had to pass a circle on the Sarte ring in 3 minutes and 30 seconds. But in reality, Bob Wollek was able to show only 3 minutes and 46 seconds in qualifying – the 18th time … Changing the gear ratios in the gearbox greatly improved the situation, but aerodynamic resistance remained the main problem. A hefty rear wing stabilized the car remarkably and improved cornering behavior, but critically reduced top speed.
The situation in the race was also so-so: Bob Wollek was able to get into the top 10 at first, but gradually the car lost momentum, his shifters fell to 20th place, then he almost ran out of gas, in the evening Xavier Lapeyre turned around and injured his back car – it took half an hour to repair. But in the end, at the eighth hour of the race with an oil leak, the engine “ran out”. Infamous finish…
A swan song
But that was not all. The 1981 season was coming to an end, and the Kremer brothers decided to give the “nine hundred and seventeenth” one last chance – after all, the next year the car could no longer be exhibited due to a change in the rules.
The team announced for the last race of the season – “Brands Hatch 1000 kilometers” – a duo of two French aces, Bob Vollek and Henri Pescarolo.
The track at Brands Hatch is much more twisty than Le Mans with its straights, and here the lack of maximum speed did not interfere at all: Wollek qualified third and fought confidently in the leading group, at some point even leading the race.
“Brilliant Bob” literally flew along the track. “I was behind Manfred Winkelhock on the latest Ford C100 prototype. I sat on his tail circle after circle. The car was good: it was easy to handle, it was perfectly balanced, with good grip on the wheels and a responsive engine, ”Vollek recalled.
While on lap 52 in the Dingle Dell turn, the car did not turn around. “The motor was running and I put in first gear to continue the race. But the steering wheel did not turn – the suspension broke, although I did not hit anything, ”said the pilot.
“When I got to the pits on foot, Manfred Kremer was furious – they say I was driving too fast and broke the car. “It’s impossible to drive the 917 at such a speed as to keep up with Winkelhock in a new car,” he said.
But it was not a pilot error: apparently, the breakdown happened from metal fatigue. Bob Wollek later said: if the engine had not “run out” at the 24 Hours of Le Mans, the suspension could have broken at that race – and then the consequences would have been much more tragic.
This is how the last race of the last Porsche 917 happened. After that, the unique car was kept by the Kremer brothers, and as a result was sold to a private collection. The current owner bought it in 2011 to compete in historic competitions like the Le Mans Classic.
The racing fate of this Porsche 917 K81 was not a happy one – but the car will definitely be remembered by everyone for its incredibly bizarre biography …
