Porsche 917/10

The Porsche 917/10

The Porsche 917 is considered by collectors to be the most sought-after racing car the brand has ever built and has been fetching top prices for two decades, regardless of market conditions. The reason for this is obvious: the 917 represented the culmination of a development that began in 1966 with the 906 model and ushered in a new era of Porsche racing cars. Although the 908 with its three-liter engine won the world championship in 1969, Porsche feared that its performance would not be enough to achieve overall victory at Le Mans – a goal that was just as important to the manufacturer as triumphing over the Ford GT40, Lola T70, and the expected McLaren Group 4 Coupé. When the FIA lowered the production requirements for Group 4 five-liter sports cars from 50 to 25, Porsche saw its chance and the 917 was born. Based on the 908 chassis, the 4.5-liter 12-cylinder 917 with aluminum tubular frame was unveiled at the Geneva Motor Show in March 1969. On May 1, after 25 units had been built, the FIA homologated the 917 as a Group 4 sports car. Despite its enormous performance, the 917 was not a success at first. Its demanding handling deterred many factory drivers, who preferred the more manageable 908. During practice runs at Le Mans in 1969, drivers reported that the car was unstable at speeds of over 200 mph on the straights. But, the 917 almost won on its debut there – impressive proof of its extraordinary power and speed.

Nevertheless, the 917 achieved its first victory in August 1969 in Zeltweg, Austria, with a short-tail coupé version. Over the winter, the John Wyer Racing Team (JW Racing) took over the 917 from the factory. Wyer had the rear end of the car redesigned—it was modeled on the Lola T70 coupe—which immediately improved the car's previously critical handling characteristics. Under the leadership of Wyer's Gulf Oil-sponsored team, the 917 won the World Manufacturers' Championship in 1970 and 1971 before being banned again due to a rule change in favor of three-liter prototypes. Porsche's first overall victory at Le Mans was achieved by a 917K entered by the Porsche Salzburg team. In total, the 917 won 15 of 24 World Championship races in those two years – 11 of them with Gulf-Wyer cars. Looking at this race car's impressive track record, it is clear that the 917 is one of the five most significant sports prototypes in history. No other two-seater race car has achieved more success in the World Championship, the Can-Am series, and the Interseries. Its greatest triumphs include victories at the 24 Hours of Le Mans, the 24 Hours of Daytona, the 12 Hours of Sebring, and the 1000-kilometer races at Monza, Spa, and the Nürburgring. No matter which race track you name, the 917 was there and dominated it.

As was so often the case, the decisive driving force behind the multi-million dollar development of the 917 was the desire to win the legendary 24 Hours of Le Mans race. But, typical for Porsche, it didn't stop there: the company also set its sights on the prestigious American Can-Am racing series. After all, around half of Porsche's total production at that time went to the United States – with further growth potential in sight. Porsche had already designed and tested the first open-top versions of the 917 specifically for the Can-Am series in 1969. This championship featured vehicles with enormous engine power that could only be mastered by drivers with exceptional stamina, determination, and driving skills. It was in this environment that the talented Swiss racing driver Jo Siffert entered the scene – a driver who had the ideal prerequisites to successfully drive the 917 in this demanding racing series.

Jo Siffert was the most important driver in the Porsche factory team at that time. Not only had he proven time and again that he was one of the fastest drivers of his generation, he also showed remarkable loyalty to Porsche. Born in Fribourg, Switzerland, Siffert began his motorsport career on two wheels and enjoyed early success in motorcycle racing before entering Formula 1 as a privateer in 1962. He later raced for the Swiss team Scuderia Filipinetti and, from 1964, for Rob Walker Racing, where he achieved victories and gained international fame with his thoughtful driving style and distinctive helmet bearing the Swiss cross. In 1969, Siffert competed as a semi-official Porsche driver in the North American Can-Am series, where he drove the open-wheel 917 PA (Porsche-Audi). The following year, he took on a special role: he appeared in the legendary Steve McQueen film Le Mans. The 1970 24 Hours of Le Mans race also served as the setting for the film's shooting – and the Porsche 917 in Gulf livery shown in the film, driven by the main character Michael Delaney, was actually driven by Jo Siffert and Brian Redman. Steve McQueen, who was a close friend of Siffert, drew heavily on him for inspiration when portraying his film character Michael Delaney – right down to details such as the racing suit and wristwatch, which matched Siffert's personal style.

Chassis 917/10-002

In 1971, Jo Siffert went one step further: for the Can-Am season, he acquired a specially built Porsche 917/10 Spyder with an aluminum chassis – a unique model with the chassis number 917/10-002, which is one of the most sought-after examples today. The vehicle was completed in July 1971 and subsequently completed just 24 test laps on the in-house Can-Am track in Weissach. It was equipped with a 4.5-liter engine and weighed just 733 kilograms. The very next day, the car was shipped by air freight to Watkins Glen in the USA. There, the 917 was given a new identity – shaped by Siffert's entrepreneurial spirit and creativity. As an experienced racing driver and astute businessman, Siffert secured a sponsorship deal with STP shortly before training began at Watkins Glen. Overnight, the car was repainted from its original white to a striking fluorescent red and adorned with a large STP logo – a visually and marketing-wise striking appearance. Siffert's team consisted of two talented Swiss racing mechanics: Edy Wyss and Hugo Schibler. Both were instrumental in the development and construction of the vehicle, which was completed in less than four weeks at Plant 1 in Zuffenhausen. Together, they formed a well-coordinated unit that made the Porsche 917/10 Spyder an icon of the Can-Am era.

The race weekend at Watkins Glen took place from July 23 to 25, 1971, and featured a very interesting duel between the 917K and the 917/10. It is noteworthy that a six-hour FIA World Championship race was held at Watkins Glen that same weekend, in which Siffert also competed. His best time in the 917K was 1:08.510, compared to 1:08.640 in the 917/10. This clearly showed that the barely mature, brand-new /10 was just as fast as the mature, factory-supported 917K. Perhaps most impressive, however, is the fact that Siffert finished second in the FIA race and achieved a very respectable third place in the first Can-Am race for chassis 10-002. After its debut at Watkins Glen, Jo Siffert, his team, and the 917/10 Spyder remained in the US for the rest of the season to compete in further rounds of the Can-Am series. The team achieved a series of impressive results:

Mid-Ohio – 2nd place
Elkhart Lake – 2nd place
Donnybrook – 5th place (after the car ran out of fuel)
Edmonton – 4th place
Laguna Seca – 5th place

At the end of the season, Jo Siffert finished fourth overall with the 917/10 – an outstanding achievement, especially considering that he had only competed in six of ten possible races with the 917/10-002 chassis. Tragically, this success story came to an abrupt end when Jo Siffert was killed in a Formula 1 racing accident in October 1971. His death was a great loss not only for Porsche, but also for the entire motorsports world, which lost one of the most talented and charismatic drivers of his time. 

After Siffert's death, the Porsche 917/10 was sold to Willi Kauhsen from Aachen. Kauhsen was a close confidant of Siffert and had close ties to the Porsche factory team, for which he worked as an independent test driver. Due to his intensive work with the 917 cars, he is probably considered the driver with the most kilometers ever completed in a Porsche 917 – proof of his enormous experience and technical understanding of this complex racing machine. Chassis 917/10-002 then returned to the factory racing department in Zuffenhausen, where it was extensively reworked and prepared for use in the European Interserie. This racing series was essentially the European version of the Can-Am series and served as a successor platform for the powerful sports prototypes after the regulations of the World Championship for Makes had changed. In the wake of this restructuring, numerous 917 models took part in the Interserie, which soon became a popular venue for the most spectacular and powerful racing cars of their time. The 917/10-002 continued the model's impressive success story there – now under the leadership of one of the most experienced Porsche drivers ever.

Willi Kauhsen achieved remarkable success with the 917/10-002 chassis and became a fixture in the Interserie. He fought thrilling battles with Leo Kinnunen, who competed in a factory-supported 917, as well as with numerous former Can-Am cars – including McLarens, BRMs, and Lolas, which were being used on European race tracks for the first time. After the first three races, Kauhsen had his car fitted with a turbocharged engine in order to outperform the growing competition. The conversion made the 917/10-002 a serious contender against the most powerful cars of the time. Kauhsen competed in nine races during the 1972 season, achieving seven podium finishes and finishing the championship in second place overall – an extraordinary result and an impressive continuation of the legendary 917's success story. 

But the year ended tragically: in September 1972, Kauhsen suffered a tire blowout at the Nürburgring, damaging the 917. Fortunately, Kauhsen himself escaped with minor injuries. Despite the accident, he decided to keep the car. The damaged race car was eventually stored in his brother's possession for 25 years – a silent testimony to the eventful history of one of the most fascinating Porsche race cars of all time.

In 1998, the Porsche 917/10-002 underwent a comprehensive restoration. The vehicle was completely rebuilt – by the same Porsche experts who had been involved in its original development at Porsche in the early 1970s. This authentic restoration ensured that every detail of the car corresponded to its condition at the time of delivery, both technically and visually. After completion of the work, the project was inspected and officially approved by Porsche itself. This is documented in a letter from Klaus Bischof, a long-time Porsche employee who was responsible for chassis 002 on behalf of Willi Kauhsen at the time. In the letter, Bischof, former director of the Porsche Rolling Museum, confirmed the authenticity and factory conformity of the restoration carried out in accordance with the condition of the car in 1972.

The reconstruction of the Porsche 917/10-002 was based on the original Porsche design drawings and the original chassis fixtures, which were in the direct possession of Porsche AG. This enabled the reconstruction to be carried out with the utmost precision and authenticity – entirely in line with the original factory standards. The engine and transmission, both original components from the 917 era, were completely overhauled by renowned 917 engine specialist Gustav Nietsche. Nietsche, who is considered one of the leading experts on the complex twelve-cylinder engines of these vehicles, ensured that the drive and technology once again corresponded exactly to the specifications of the Can-Am racing version of the time. The body was manufactured in accordance with the 1971 Can-Am specifications and then painted in the characteristic STP red – the iconic color scheme that made Jo Siffert's 917/10 world famous during his American racing season. The result is a vehicle that represents an authentic resurrection of the legendary 917/10-002, not only technically but also visually. After completion of the extensive restoration, the fully reconstructed Porsche 917/10-002 was returned to its intended purpose – driving. Willi Kauhsen himself presented the vehicle at various demonstration and classic car events, including prestigious appearances at the Goodwood Festival of Speed and the AvD Oldtimer Grand Prix at the Nürburgring. These appearances impressively demonstrated that the 917/10 is not just a museum piece for collectors, but remains a fully functional racing car of extraordinary fascination and performance.

The next chapter in the history of 917/10-002 took place in the USA, where the car was exhibited in a renowned private collection for over eight years. In 2008, it was purchased by a German collector, who kept the car until 2012. Another change of ownership followed at the end of 2012, and the 917 found its new home in an extraordinary Porsche collection in Monaco. After acquiring the Porsche 917/10-002, the new owner had the car restored to its original delivery appearance—the white paintwork that the vehicle had when it was originally shipped to the United States. At the same time, the previously distinctive, angular bodywork was replaced with a more rounded body shape that corresponded to the late stages of development of the 917. In this configuration, the car was driven by racing legends Jürgen Barth and Gérard Larrousse at the Dix Mille Tours at Circuit Paul Ricard in 2015 – a symbolic appearance that impressively underscored the historical significance of the 917/10. In 2017, the owner decided to restore the 917/10 to Jo Siffert's legendary STP livery – the iconic fluorescent red that is inextricably linked to the Can-Am era and Siffert's performances. The remaining, previous bodywork was also remounted on the car during this process. In addition, the vehicle was equipped with headlights to enable it to compete in the Peter Auto CER (Classic Endurance Racing) series. This marked another milestone in the eventful history of this unique Porsche racing car.

Over the past few years, the car and its owners have participated in numerous historic motorsport events, underscoring the endless possibilities this racing legend offers its future owner. 

2024 Spa Classic
2019 Techno Classica
2018 Spa Classic
2018 Espiritu de Montjuic
2015 Dix Mille Tours
2013 Dix Mille Tours
2009 Goodwood Festival of Speed

Today, this Porsche 917/10 is back on the market after being purchased by our company. A unique opportunity for any high-caliber Porsche collection. Our sales staff is available at any time to answer your detailed questions. Please note that vehicle viewings are only possible by prior appointment.