If you're like me, combining the words 'Porsche' and 'Le Mans' instantly brings vivid thoughts of the insane looks and ferocious sound of the 917.
The car that gave Porsche their very first overall win at Le Mans, setting them up on their journey to becoming the most successful team ever at the iconic French circuit. Although like many first time success stories, the 917 didn't exactly get off to a flying start (well it kind of did, thanks to the lack of aero...).
The story begins in 1968 when the governing body of sports racing ruled that the sports prototype cars should have engines no larger than 3 liters, since the one-off prototype cars of the era were becoming far too fast and dangerous, however they also said that if a manufacturer could build 25 road going versions of the car then the engine limit would be raised to 5 liters. Porsche's head of motorsport at the time was Ferdinand Piëch, described as a very intense man he was absolutely obsessed with getting the overall win at Le Mans - so he decided to take the challenge of building the 25 of their new race car to enter the top class of Le Mans.
This started the development of the 917, powered by a 5 liter flat-12 engine, the car was an absolute monster. In typical Porsche form the car was build to meticulous detail and was full of innovation to ensure that they had the edge over the competition.
Innovations included a space frame chassis, built from many small tubes that play on the strength of a triangle, the entire chassis only weighed a total of 42KG. Each tube diameter was selected for a pre-determined strength calculation so they were only as big as they needed to be, with a very small strength margin - this meant that each chassis could typically only be used for one race, as they weren't designed to last any longer. Due to the design the chassis could be prone to cracking, which would then lead to a catastrophic end, so the tubes were pressurized with nitrogen and then monitored during the race, so that if the pressure dropped they knew that cracks were forming and could stop the car before more damage was done. In the cars first year they even used some of the chassis tubes as the oil tank, but this was later stopped as drivers were complaining of extreme heat in the cockpit.
With Porsche's extreme weight saving approach the car came in at almost 800 kilograms. When you combine this with 621 break horsepower to give over 750 BHP per tonne you realize how much of a rocket ship this car really was, especially in 1969.
Back when Porsche started development of the car they weren't the well-known giants of the car world that you know today, in fact they were a very small cash-starved company - and the race team was even smaller. So when Piëch decided to devote so many resources just to go for the win at Le Mans you can be sure that Ferry Porsche was not happy, it is said that there were many arguments about money/resources over the years, and it got to the point that Piëch actually personally guaranteed the development costs of the 917, as to not put the company at too much risk.
You can be sure that money wasn't the only strain Piëch put on the company - when it came to getting the 25 cars checked and homologated for the Le Mans race, it was only a few months away. So everyone - really, everyone in the company was called to help. Office juniors, accountants and the likes were all hauled off into the production line to help get the cars ready. They had only just made the deadline but managed to get the cars signed off by the motorsport inspectors, giving them the go ahead to enter at Le Mans 1969.
A total of 3 Porsche 917s started in the race, and despite the insane raw power of the car - it went disastrously. John Woolfe piloting a privately entered 917 fatally crashed on the first lap, triggering a change of rules for the following years to stop the traditional 'Le Mans start' (where the drivers had to run across the track to their car when the race started.) - and one by one all other 917s failed. The last car failed during the 22nd hour and was actually in the lead by 6 laps - showing the potential of the car (One of the cars was actually recorded going in insane 238MPH on the Mulsanne straight).
Driver, Dickie Atwood did say that he was happy the car broke though as it was a 'monster' to drive. At high speeds the rear of the car was lifting off the ground, at times drivers said they could see the sky in the rear view mirror - not exactly what you want at 200+ MPH... Development was definitely needed if they were to succeed the next year.
Le Mans 1970
Ahead of the 1970 race Porsche signed an agreement with John Wyer - previously of GT40 fame to help them with the development of the car, the JWA Gulf team would later become and official Porsche team and development partner. While testing at the Österreichring track in Austria chief engineer John Horsman noticed that there was a large amount of dead bugs splatted all over the front of the car but not at the tail - this told them that the airflow wasn't getting to the back of the car hence the massive instability and cornering issues that the car faced in the previous issue. They then proceeded to create a new tail for the car on the spot out of aluminium sheets taped together and retrofitted it to the car, after only 10 laps they could see a massive improvement and knew this was the direction the car needed to take - the birth of the 917K (Kurzheck, or "short tail").
With the instability tackled, Porsche took a total of 7 917s to the 1970 Le Mans race - a mixture of the new 917Ks developed by John Wyers gulf team and some new 917L's which were an updated version of the previous years longtail, piloted successfully by the Martini racing team.
Although heavy rain starting taking them out one-by-one they ended up ending the race in the first and second position, giving Porsche their first ever win at Le Mans. The winning car was a 917K piloted by Richard 'Dickie' Attwood (Who piloted the leading 917 the previous year) and Hans Herrmann. The car was so dominant that they also won the next year with a 1-2 finish, breaking both the speed records and distance records in the process. The speed record would only be beaten around 20 years later, and the distance record not until 2010. (917's also broke the fastest qualifying and in-race lap records that year)
1971 would be the last year that the 917 graced the Le Mans race as the rules were then changed to limit engine size to 3 liters. They then set their sights on dominating the Can-Am championship, but that's a story for another day...