1977 Porsche 936

The Porsche 917 sports prototype race car provided the factory with its first overall victory at the 24 Hours of LeMans in 1970 and 1971. The Group 4 class was abandoned at the end of the season by the sport's governing body, making the Porsche 917 obsolete. The 1972 World Championship regulations dictated a 3-liter engine capacity for the racing prototypes. Instead of building a car to comply with these rules, Porsche began work on modifying the Porsche 917 for the Canadian-American Challenge Cup (Can-Am) Series.

The 5-liter, flat-12 cylinder engine in the 917/10 was underpowered when compared to the rest of the competition. More power was needed with 'how' being the difficult question. Options included a 16-cylinder engine, a bigger engine displacement, or a supercharger. Each had pros and cons, along with problems to overcome. Twin turbocharging was also a potential solution, and a direction Porsche wanted to go. At the time, turbocharging was still rather new, and it was not known if it would work as hoped. Turbocharging works best with high engine speeds, which meant it would be less effective during cornering. Additionally, the 917/10 produced a tremendous amount of power, and when the turbochargers kicked in, would the car and driver be able to handle the power.

Having solved the many questions and modifications, the new car was called the Porsche 917/30. It could go from zero-to-sixty mph in under 2 seconds and could reach speeds in excess of 240 mph.

In Europe, the sportscar racing scene had stricter regulations which included a limit on displacement of three liters for the Group 6 class. Porsche had withdrawn from competition, but privateers continued to race the 908/3 with the three-liter engine. The flat-eight cylinder engine, however, was underpowered compared to its competition. To resolve this issue, Porsche turned to their turbocharged 917/30 for inspiration.

The engineers at Porsche began work on a new flat-6 engine with a single Turbocharger. The additional heat produced by the turbocharger was resolved by an intercooler which cooled the compressed air traveling into the engine. This marked the first time this setup was ever used in a racing car. Additionally, FIA rules dictated the engine size for the turbocharged engine could not exceed 2.143 liters. The Porsche engine measured 2.142 liters.

The new turbocharged engine made its debut in a 911 RSR body in 1974. Having been installed in a road-going chassis, the car was homologated as a Group 5 car. During the season, the engine setup showed potential but it also revealed the need for more development work.

For 1975, Porsche introduced the road-going 911 Turbo Type 930, which lead to the Group 4 (934) and Group 5 (935) racing cars that would race successfully for many years.

Porsche re-entered the World Championship in 1976 with a new Group 6 car. It was a conglomerate of the many past racing cars including the tubular spaceframe from the 908/3, the spyder body of the 917/30, running gear from the 917, and the 2.1-liter turbocharged engine. By this point, the six-cylinder engine offered over 500 horsepower.

The 936 received its name from the Porsche 930's turbocharged engine and the Group 6 racing category. It was designed to comply with both the World Sportscar Championship and the 1976 24 Hours of Le Mans under the Group 6 formula.

The Porsche 936 made its racing debut in the Nürburgring 1000 km race where a mechanical issue kept the car from realizing its true potential. The day was not lost for Porsche, as a turbocharged 908/3 won the race.

Development work continued throughout the season on the 936. It was given a large air scoop the aid in cooling the engine block. Additional cooling was provided by a front-mounted radiator.

Jacky Ickx and Gijs van Lennep drove one of the two 936s to an overall victory at LeMans in 1976. This would be the beginning of the 936's dominance in motorsports, as it won the remaining six rounds of the World Sports Car Championship. The Group 6 car did not provide Porsche with the World Manufacturer Championship. That title was contested for the Group 5 cars only. Thankfully for Porsche, their Group 5 935 won that group as well, earning Porsche the victory they desired.

For the 1977 season, Porsche focused on another victory at LeMans with the 936 and left the 935 to contest the other races. To get the 936 prepared for the high-speed circuit, they began work on a low-drag body for the 936 and replaced the single turbocharger with two smaller Turbochargers with better throttle response.

At LeMans, Renault's three turbocharged A442s outpaced the two 936s. During the race, Jacky Ickx's number 3 car (chassis number 0002 which had won the previous year) encountered mechanical problems, so Ickx joined Hurley Haywood and Jürgen Barth in the team's #4 sister chassis 001. As the hours ticked away, the Renault was in the lead. Skillfully, Ickx was able to take the lead and score his 4th victory. A tremendous accomplishment as one of the pistons on the engine had failed. The car had entered the pit lane blowing smoke out of the engine. The car was still had to complete the final lap in under fifteen minutes, which it did.

For the 1978 LeMans race, Porsche developed the 936 further, fitting it with a 24-valve engine. The engine offered 640 horsepower which helped give it pole position. Although quick, Renault had brought four cars that were very competitive. Three were plagued by mechanical issues leaving the final Renault to contest the victory - which it did. The Porsche 936 earned second.

Porsche returned to LeMans in 1979 with the 936. It again claimed the pole position. Unfortunately, the two cars retired early. One Porsche 936 experienced engine failure while the other was disqualified.

A Porsche Works car did not compete at LeMans in 1980.

A total of three Porsche 936 race cars were built by the factory. They were raced by the factory and never available for privateers. However, Porsche did provide the plans to Erwin Kremer and Reinholt Joest. Using the plans, Joest built a 936 while Kremer upgraded an existing 908. There is speculation as to whether Joest actually built the car or if Porsche ultimately supplied a complete car. Later, Kremer also built or received a 936. Either way, Joest had the car painted in the traditional Martini colours and entered it in the 1980 LeMans 24 Hours where driving duties were shared with Jacky Ickx. The car performed tremendously well, leading the race until it was forced into the pits due to a failed fifth gear. After repairs were made, the car re-entered the race and clawed its way back into a second-place finish, just two laps behind Jean Rondeau and the checkered flag. The following year, Jacky Ickx and Derek Bell would drive the 936/81 to an overall victory, 14 laps ahead of second place Rondeau M379.

During its racing career, the 936 won at LeMans on three occasions and had earned on World Championship. It was replaced in 1982 by the 956, which unlike the 936, had a new body and chassis. The six-cylinder turbocharged engine from the 936 found new life in the 956.

by Daniel Vaughan | Apr 2019