Model history: At the end of the 1971 season, the coupe bodied Porsche 917 was no longer eligible to race in the world championship, which saw the German manufacturer's focus shift to the Group 7 class. In open form the 917 had been campaigned in this virtually no limits class since 1969, but with little factory support. Two championships were open for the Group 7 cars; the European Interserie and more importantly the North American Can-Am Challenge. Big engines, low weight and a host of different looking vehicles had made Can-Am one of America's premier classes, attracting many spectators.
Porsche was represented in Can-Am for a number of years by privateers who race 908s or decapitated 917s, until a purpose built Group 7 version of the 917 made its debut in 1971. Dubbed the 917/10, it was technically similar to the coupe 917, but featured a number of lighter components constructed from the latest exotic materials. A larger fuel tank was also fitted to enable the car to complete the 200 mile races without having to refuel. Completely new was the spyder bodywork, which was an adaptation of the contemporary Can-Am design.
A few races into the 1971 season, the Porsche 917/10 made its debut in the McLaren dominated series. It was immediately obvious that the 5 litre flat 12 was not powerful to take on the might of the all-alloy Chevrolet V8s, but nonetheless valuable points were scored in the car's first season. Back in Germany two options to close the gap with the 800 bhp V8s were considered; a 16 cylinder version of the 917 or fitting Turbochargers to the existing engine. The second option was by far not as easy as it sounds today, but it was expected to offer the best performance so it was fully explored.
In the preceding fifty years racing cars were either Naturally Aspirated or equipped with a Supercharger driven by the crank; exhaust driven Turbochargers was uncharted territory. Throttle lag was the biggest problem to overcome with Turbos. In order to operate ideally the turbines in the Turbo had to run at a specific speed, but that requires a minimum amount of engine revolutions. When the engine was running under that number, there was considerably less power, and when the Turbos did kick in it was not a gentle affair. Drivers of the Turbocharged 917s needed to have a very delicate right foot and stellar reflexes to cope with the sudden power increases.
In five litre form, the Turbocharged flat 12 was good for around 950 bhp; not for the faint of heart. In Mark Donohue and George Follmer Porsche found two drivers brave enough to take on the competition in their 917/10K. Donohue proved to be the faster of the two, but an accident early in the season left him out for most of the remaining races. This paved the way for George Follmer to finally challenge and beat the McLarens and secure the championship. In Europe the 917/10Ks were campaigned in 4.5 litre form, but it was still enough to clinch a one-two in the championship.
Although the McLarens were convincingly beaten in 1972, Porsche continued the development and constructed the most powerful racing car ever. Available only for Team Penske's driver Mark Donohue, the 917/30 was bigger in every aspect compared to the 1972 racer. The engine's displacement was increased to 5.4 litre, which saw the performance rise to at least 1100 bhp in race trim. A new longer and aerodynamically efficient body was fitted, which increased the top speed considerably. In the 1973 season there was no stopping the 'Turbo Panzer', and Mark Donohue won the championship.
As a side effect of the Porsche dominance, Can-Am was quickly losing teams and spectators and halfway through the 1974 season the challenge was cancelled. Porsche had also withdrawn at the end of the 1973, but the 917/30 was given one final outing in 1975. Specifically prepared for a high speed run, Donohue lapped the Talladega race track at an average of 221 mph in the 917/30, setting a new world record. A fitting finale for the Porsche 917's magnificent career. Unfortunately it was also the finale of Donohue's career, who fatally crashed ten days later during Formula 1 qualifying in Austria.
Chassis: 917/30-001
Built for testing purposes, the first 917/30 was equipped with an adjustable chassis, which allowed for different wheelbases. It was completed late in 1972 and extensively tested before the two cars for Penske were produced. In 1973 it was race three times in the European Interserie Championship with a victory at Hockhenheim in the hands of Vic Elford as the best result. Porsche retained the car and restored it to the original Martini colours. Chassis 917/30-001 has since been loaned to various exhibitions and museums, including the Sinsheim Museum where it is seen here.
Chassis: 917/30-002
Chassis 917/30-002 was one of two cars readied for Team Penske and Mark Donohue's 1973 Can-Am challenge. It was driven to the type's first Can-Am victory in the third round of the season at Watkins Glen. The car was subsequently heavily crashed and although it was completely rebuilt it served as a T-car for the remainder of the season. After the Can-Am program had ended chassis 002 was returned to Porsche and it has since been a proud part of its museum collection. In addition to being displayed prominently, it also regularly driven particularly at the Goodwood Festival of Speed where it is almost an annual entry.
Chassis: 917/30-004
Under construction for the 1974 season, chassis 917/30-004 was redundant following Porsche and Penske's withdrawal from the Can-Am series. Once completed, it was sold in plain white livery to Australian Porsche importer Alan Hamilton. He displayed the car for many years in his showroom and also showed at various events like the Australian Grand Prix in Adelaide. It returned to Porsche ownership in 1991 when the company acquired Porsche Australia from Hamilton.
Returned to Weissach, chassis 004 was refinished in the iconic 1973 Can-Am series winning Sunoco livery. After an outing in the Old Timer Grand Prix at the Nürburgring in 1992, it was sold to an American enthusiast. Before shipment, the car was fitted with a rebuilt engine, using the last remaining 5.4 litre block. At 1.4 bar turbo pressure, the massive flat 12 produced a staggering 1,200 bhp during a dyno test. In 1998 it was driven to victory during the Monterey Historics by Porsche factory driver Olaf Lang.
Young Porsche collector Matt Drendel bought the car in 2001 and until his untimely passing in 2010, he showed the car at various events. An absolute highlight was the first Rennsport Reunion where it was driven for several laps by Roger Penske after Porsche's own example had mechanical problems. Along with the rest of Drendel collection, the 917/30 will be offered in Gooding's 2012 Amelia Island auction. For the rare privilege of acquiring one of the most powerful racing cars ever, Gooding estimate at least $3.25 million is needed but it would not surprise us if the final bid far exceeds that.
Chassis: 917/30-006
With the 917/30 program coming to an abrupt end at the end of 1973, three of the six frames were never completed in period. Chassis 917/30-006 was already at Penske's workshop ready to be built up as one of the 1974 team cars when the Can-Am entry was axed. In 1982 the existing parts were acquired by legendary Porsche dealer Vasek Polak and he set about assembling sufficient parts to complete the car. He finally succeeded in 1995 and shortly after sold the car. Since then it has been regularly raced and is seen here at the 2009 Monterey Historic Races where Porsche was the featured marque.
One of the errors I noticed was listing 917/30-002 (and -003) as havingbeen driven by David Donohue, when it was Mark (David's dad) who drove these monsters. Even though I was only 9 when he died (10 days after setting the world's closed-course speed record in the red Cam-2-liveried 917/30-003, which is back in penske colors and currently for sale), Mark is still my all-time favorite race driver.
One of the forum members commented that the 917 engines were flat-12's not V-12's. Both are actually correct. Flat configured engines have 2 types; the more familiar "Boxer," in which opposing cylinders run on separate crank journals so that they move in and out in phase with each other, and 180 degree v-12's (such as the type 917 engines), where opposing pistons share a common crank journal, so they move the same direction. The 180 degree v-12 has the advantage of being more compact and having a stronger, stiffer crank, while the boxer is easier to set up and dynamically ballance.
Engine Configuration
MountieFan16 08-04-2011
Just a comment on a minor error in the report on the Porche 917/30: Under the engine description data, it shows the engine as being a V-12. As we all know, the engine was a flat 12. Nothing major on a well written article.
Mark Donohue's Book
kurt38 08-28-2007
Get Mark Donohue's book, "The Unfair Advantage," it will give you a whole new respect for this car and driver.
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At the end of the 1971 season, the coupe bodied Porsche 917 was no longer eligible to race in the world championship, which saw the German manufacturer's focus shift to the Group 7 class. In open form the 917 had been campaigned in this virtually no limits class since 1969, but with little factory support. Two championships were open for the Group 7 cars; the European Interserie and more importantly the North American Can-Am Challenge. Big engines, low weight and a host of different looking vehicles had made Can-Am one of America's premier classes, attracting many spectators.
