Porsche 936

Porsche
Porsche 936/77, driven by Henri Pescarolo in the 1977 Le Mans 24-hour race
936
Production period:	1976-1982
Class :	race car
Body versions :	Spyder , coupe
Engines:	Gasoline engines : 2.1–2.65 liters (382–455 kW)
Length:	4150-4950 mm
Width:	1920-1980 mm
Height:	1010-1270 mm
Wheelbase :	2400-2410 mm
Empty weight :	700-780 kg
Previous model	Porsche 908
successor	Porsche 956

The Porsche 936 is a racing car from Porsche . The car, built according to the FIA regulations of Group 6 , was used by the works team from 1976 to 1979 and 1981 in the sports car world championship and the 24-hour race at Le Mans .

1976 Porsche won the 936 in parallel with the Group 5 used Porsche 935 both titles in the sports car and manufacturers' world championship. At Le Mans, the racing car won the 24-hour race in 1976, 1977 and 1981.

In addition to the works team, the private racing teams Joest Racing and Kremer Racing each built a 936 and competed in the sports car world championship, the interseries and the German racing championship (DRM). With the car, the Joest team won the DRM title in 1982 with Bob Wollek .

General

For 1976 the FIA ​​announced, in addition to the existing brand world championship, in which Group 5 cars started, a sports car world championship for Group 6 sports cars. Porsche originally planned to compete in the brand world championship only with the 935. However, the uncertainty about a future merging of the two racing series and the prestige of the supposedly more difficult sports car world championship prompted Porsche to develop a Group 6 car. This decision was risky as there were only a few months to develop the vehicle. Therefore, the designers used existing and proven parts from other racing cars such as the Porsche 908/03 , 917/10 and 911 Carrera RSR Turbo 2.1 . The result was the Porsche 936 Spyder, which won the world championship with five wins in seven races and was able to assert itself against the Renault-Alpine A442 .

Porsche built three vehicles from the 936 with the chassis numbers 936 001 to 936 003. Later, the private teams Joest and Kremer built two more cars with the numbers 936 004 and 936 005.

Model development

936 Spyder (1976-1981)

body

The body of the 936 was derived from that of the 908/03 and 917/10. A slippery plastic skin made of polyester was attached over the aluminum tubular space frame, which consisted of the front part derived from the 908/03, the middle part with hinged doors and the rear part taken from the 917/10. The front had a large opening in the middle for the oil cooler and the supply lines for the ventilation of the front brakes. The headlights were installed behind transparent plastic panes integrated flush with the body. The two exterior mirrors were initially mounted on two short rods above the front fenders.

The driver sat in the two-seater cockpit on the right in a bucket seat. Few instruments were installed in the dashboard to inform him about the condition of the vehicle. The large tachometer placed behind the steering wheel was dominant. The stern had a large, two-part, adjustable wing that ran the full width. This was mounted on two vertical fins attached to the outer edge of the vehicle. In addition, the wing was supported in the middle. The engine sat as a mid-engine in front of the rear axle directly behind the cockpit. The transmission with the limited slip differential was behind it.

In order to achieve a good air supply for the engine, Porsche tested various rear shapes, which mainly differed in the engine cover behind the cockpit. Initially, the developers opted for the flat shape, in which the body was guided directly above the engine and a roll bar was mounted behind the cockpit to protect the driver. At the 24-hour race at Le Mans in 1976 , Porsche used the version with a raised engine cover and a large air scoop for the second car. From 1977 onwards, all 936s had an air inlet opening above the cockpit, which was used to improve the flow to the intercooler . So that the vehicle had a neutral driving behavior, the petrol tanks, which held a maximum of 160 liters, were installed on the left, right and behind the cockpit. The oil tank was behind the driver in the engine compartment.

Porsche 936/77 Spyder

In 1977, in addition to the engine technology, the body of the 936/77 was also revised. The developers improved the aerodynamic properties in the wind tunnel. The exterior mirrors of the vehicle were mounted directly on the fenders and provided with aerodynamic panels. The rear section with the air scoop, which was already used in Le Mans, was taken over and its air opening enlarged. The length of the 936 was 50 mm shorter and the wheelbase was lengthened by 10 mm. The technicians reduced the track width by 50 mm at the front and 30 mm at the rear. The weight remained unchanged at around 700 kg.

The 936/78 had a specially modified body at the rear and the sides. At 4.96 meters, the car was around 800 mm longer than its two predecessors. The extended stern was strongly tapered towards the end. The adjustable rear wing, which was bent downwards on the outside, was mounted on two short fins that sat further inside instead of on the outside. On the two side surfaces there was a new large air opening in front of the rear wheel for better cooling of the rear brakes. The track widths on the front and rear axles were increased again and were 1540 mm at the front and 1515 mm at the rear. The developers adopted these dimensions for all subsequent vehicles. The weight of the racing car was around 780 kg. The body remained unchanged when it started in Le Mans in 1979.

In 1981, Porsche fielded the 936 for the last time in the Le Mans 24-hour race. The car named 936/81 did not differ externally from the 936/78. The wheelbase and vehicle length are each 10 mm shorter.

landing gear

The 936 had independent suspension with wishbones and longitudinal tension struts at the front, triangular links with a longitudinal thrust strut at the top and bottom as well as progressive coil springs and Bilstein gas pressure dampers.

The braking force distribution of the dual-circuit braking system could be adjusted depending on the driver and the route. All around the car was equipped with internally ventilated brake discs and aluminum brake calipers.

All vehicle versions had 10.5J × 15 light alloy wheels with 265/565 × 15 tires at the front and 15J × 15 light alloy wheels with 340/600 × 15 tires at the rear.

engine and gears

In 1976 an air-cooled 2.1-liter six-cylinder boxer engine was installed in the 936, which had already been used in the 911 Carrera RSR Turbo 2.1 racing prototype in 1974. The engine had a low compression ratio of 6.5: 1 , a KKK turbocharger and developed 382 kW (520 hp) at 8000 rpm. In addition, a charge air cooler was installed for each cylinder row. Both coolers were arranged lengthways above the engine behind the horizontally mounted fan wheel. The engine block was made of lightweight magnesium . As with the 911 series engines, the cylinders had two valves - an intake and an exhaust valve, which were controlled by a chain-driven camshaft per cylinder bank. In contrast to the engines in the Porsche 935 and 934 , the engine in the 936 had double ignition.

The developers changed the turbocharger for the car used in 1977. Instead of one turbocharger for both rows of cylinders, two turbochargers (one for each row of cylinders) were used. This has made it possible to improve the response of the engine and increase the output by around 14 kW (20 hp) to a maximum of 397 kW (540 hp).

In 1978, Porsche fundamentally redesigned the 2.1-liter six-cylinder boxer engine. In order to cope with the thermal stress on the engine with a further increase in performance, the engine had air / water cooling. The valves were changed from two to four per cylinder. For valve control, the technicians used two camshafts per cylinder row, which were driven by gear wheels. As a result, the air cooling for the cylinder heads was no longer sufficient. Porsche developed new bag cylinders in which the cylinder heads were welded to the cylinder. The cylinder head gaskets that are otherwise required in conventional engines and are susceptible to racing were no longer necessary. The cylinder heads had water cooling, in which the cooling water was guided from the bottom up and from the outlet to the inlet side. A water pump driven by the exhaust camshaft was used for each cylinder bank. Since the fan only had to cool the cylinders, the diameter and the air flow rate could be reduced. By changing the engine cooling, the temperature on the aluminum cylinders coated with Nikasil on the inside decreased from 280 ° C for the purely air-cooled engine to 200 ° C for the water / air-cooled engine.

The turbocharging with the two turbochargers and intercoolers per cylinder row remained unchanged from the previous year's model. However, the developers changed the ignition system. Instead of the ignition distributor driven by the crankshaft, the ignition system was separated into an inductive transmitter and a high-voltage distributor. The engine converted in this way developed a maximum of 426 kW (580 hp) at 8500 rpm.

In 1979, Porsche used the 936 almost unchanged. The engine had the same power as the 936/78. Only the petrol injection had been revised and ensured that the engine ran better at low speeds.

The last 936 developed by Porsche in 1981 also had the engine with four-valve technology and water / air cooling developed in 1978. However, this engine had been further developed for use in the so-called Indy Porsche , which was to start in the Indianapolis 500 mile races. By increasing the displacement from 2.1 to 2.6 liters, the six-cylinder boxer engine delivered a maximum output of 455 kW (620 hp) at 8000 rpm.

The five-speed manual gearbox of the type 917 installed behind the engine was connected to the engine via a short shaft. A separate oil cooler was installed to cool the gearbox. All 936 had a limited slip differential to prevent the wheels from spinning when cornering.

In the 936/81 a four-speed manual transmission with a limited-slip differential was installed instead of a five-speed gearbox. With this gearbox, the racing car reached a top speed of around 360 km / h.

Joest 936 Spyder type 936/80 (1980)

body

In 1980, Reinhold Joest , his racing team and the support of Porsche built a fourth 936 in addition to the three works cars, which was given the vehicle number 936 004. The body of the 936/80 mentioned largely corresponded to that of the 936/77. The most noticeable difference was the vehicle length, which at 4960 mm was around 810 mm longer than the 1977 car. The car had an empty weight of around 780 kg.

landing gear

The chassis with the wishbone at the front with longitudinal tension struts and triangular link at the rear with a longitudinal thrust strut above and below, as well as the progressively acting coil springs with gas pressure dampers, corresponded to that of the Porsche works car. Their dual-circuit braking system with internally ventilated brake discs and aluminum brake calipers was also used.

engine and gears

While Porsche was already planning a new 2.6-liter six-cylinder boxer engine with air / water cooling for the 936/81, the Joest team built the tried and tested air-cooled 2.1-liter six-cylinder boxer engine from the 936/77 into the new one built vehicle. With the two turbochargers and intercoolers, this engine developed a maximum of 426 kW (580 hp) at 8500 rpm. With the five-speed manual transmission, the car reached a top speed of 350 km / h.

Kremer 936 Spyder Type 936/82 (1982)

body

After Joest, a second private team built a 936 with Kremer. The car called 936/82 had the vehicle number 936 005. Porsche no longer used its works car and provided Kremer with the construction plans. The private team rebuilt many parts of the car such as the aluminum space frame, landing gear parts and the tanks. The body, which corresponded to that of the 936/78 with the rear wing bent down on the outside, was taken over by the Porsche factory.

landing gear

Apart from the wheel hubs, the chassis had to be completely re-produced by Kremer. The brakes and the steering were still available at Porsche and were taken over unchanged in the 936/82.

engine and gears

The biggest difference between the Kremer 936 and the Porsche works cars was the engine. While Porsche started using a turbocharged six-cylinder boxer engine with four-valve technology and air / water cooling from 1978, Kremer built an engine like the one used in the Porsche 935. The air-cooled 2.8 six-cylinder boxer engine still had the simpler two-valve technology. Thanks to the less elaborate construction and cooling technology, the car weighed around 40 kg less than the factory car and, when fueled and ready to race, weighed 800 kg. The five-speed manual transmission of the type 917 with the limited-slip differential was supplied by Porsche.

Joest 936 Coupé Type 936 C (1982)

body

In 1982, Joest Racing converted the 936, which was designed according to the Group 6 regulations, into a Group C racing car with the chassis number 936 RJ 005. Extensive changes to the original Spyder were necessary to obtain Group C approval.

The tubular space frame was adapted to comply with FIA specifications. The vehicle width increased from 1920 mm to 1990 mm and the length decreased from 4960 mm to 4800 mm. The height of the car called 936 C was 1000 mm and had been reduced by 170 mm compared to the 936/80.

The most obvious change was the regulation-related conversion of the body from an open Spyder to a closed coupé. The weight of the vehicle increased from 780 kg to around 870 kg.

landing gear

The chassis was not changed during the conversion and was taken over from the 936/80.

engine and gears

The engine used by Joest was an air-cooled 2.5-liter six-cylinder boxer engine with two turbochargers. The cylinders had an intake and an exhaust valve, which were controlled by a camshaft per cylinder bank.

The engine developed around 411 kW (560 hp) at 8000 rpm. Together with the five-speed manual transmission, the racing car achieved a top speed of 360 km / h that was 10 km / h higher than the 936/80 Spyder because of the lower air resistance.

Racing history

1976 to 1981 - successes in the sports car world championship and in Le Mans

The Porsche 936 was first used in 1976 in the 300 km race at the Nürburgring and achieved fifth place with Rolf Stommelen . In the subsequent races of the sports car world championship, Jacky Ickx and Jochen Mass drove the car to first place. In the fifth round, the 200 miles from Mosport (Canada), only two larger-displacement CanAm racing cars from Group 7 , which were not entitled to championship points, placed ahead of the Porsche 936. Porsche won the sports car world championship with this successful series 1976 and secured the title in the brand world championship with the 935. Jacky Ickx and Gijs van Lennep also won the Le Mans 24-hour race with the 936 , which was not part of the world championship at the time.

One year later, Porsche was able to repeat the previous year's success at Le Mans with the 936/77 . The works car, driven by Jürgen Barth , Hurley Haywood and Jacky Ickx, won after a tough race in which Ickx drove the car, which was last after a repair, to first place through great driving efforts.

In 1978, Porsche competed in Le Mans with the further developed 936/78 . The two works cars used finished the race in second and third place behind a Renault-Alpine A442B .

In the 1979 Le Mans 24-hour race , the works team started as a Porsche Essex and not, as in previous years, with sponsor Martini. Both 936/79 cars were eliminated in the race. One car was withdrawn from the race prematurely due to fuel supply and engine problems. For the second car, the race ended with a disqualification due to unauthorized use of outside help.

In 1980 the Porsche works team decided not to start in Le Mans. However, the Joest Racing team competed there with a newly built Porsche 936/80. The car running under the designation Porsche 908/80 achieved second place behind a Rondeau M379B .

Reinhold Joest won the same year with the 908/80 at the interseries race in Most. In the following year, Jochen Mass drove four races in the Interserie for Joest in the racing car and achieved second place in the overall season standings.

In 1981 Porsche returned to Le Mans with the works team with the 936/81 . The car driven by Jacky Ickx and Derek Bell won ahead of two Rondeau M379C. This was the third Le Mans victory for a Porsche 936 and for Ickx the fifth overall Le Mans victory.

After this race, Porsche stopped racing the 936.

1982 and 1983 - assignments in the DRM

In the sports car world championship in 1982, the Joest team started with the Porsche 936 C, which was newly built according to Group C regulations as a coupè. The team achieved the best result in the 6-hour race in Silverstone and in the 1000 km race in Mugello celebrate a third place in the overall ranking. In the 1983 season, the private team only contested two 1000 km races in Spa-Francorchamps and Kyalami with the racing car.

In addition to the Joest team, Kremer Racing had also rebuilt a 936. Both private teams fielded their racing cars in the 1982 German Racing Championship (DRM). The 936 dominated the racing season there with a total of four wins and six second places. Bob Wollek , who started for Joest-Racing, won the DRM title and Rolf Stommelen was runner-up with Kremer-Racing.

A year later, only the Joest team started with the 936/80 and 936 C in the DRM and achieved several podium finishes with the drivers Volkert Merl , Leopold von Bayern and Stefan Johansson .

In the 1982 Interserie, the Joest team drove a full season with a 936 for the last time. Bob Wollek won four of six races with the 936/80 and finished the season in third place.

The last successful race of the 936 was in the 300 km race at the Nürburgring in 1984. There Siegfried Brunn drove a 936 C to second place in the overall standings. With this race, the nine-year history of the successful racing car ended.

The results from 1976 to 1984

1976

1977

1978

1980

1981

1982

1983

1984

Technical specifications

The Porsche 936 was produced and used from 1976 to 1982 in the following versions:

Porsche 936:	936 Spyder (1976)	936/77 Spyder (1977)	936/78 Spyder (1978)	936/81 Spyder (1981)	936/80 Spyder (1980) Joest Racing	936/82 Spyder (1982) Kremer Racing	936 C Coupé (1982) Joest-Racing
Engine:	6-cylinder boxer engine (four-stroke) 1976 one exhaust gas turbocharger, from 1977 two exhaust gas turbochargers with two intercoolers
Displacement:	2142 cc		2140 cc	2650 cc	2140 cc	2806 cc	2517 cc
Bore × stroke:	83.0 x 66.0 mm		87.0 x 60.0 mm	92.3 x 66.0 mm	87.0 x 60.0 mm	92.0 x 70.4 mm	90.0 x 66.0 mm
Performance at 1 / min:	382 kW (520 hp) 8000	397 kW (540 hp) 8000	426 kW (580 hp) 8500	455 kW (620 hp) 8000	426 kW (580 hp) 8500	433 kW (590 hp) 7900	411 kW (560 hp) 8000
Max. Torque at 1 / min:	480 Nm at 6000	490 Nm at 6000		539 Nm at 6450		588 Nm at 5400
Compression:	6.5: 1		7.0: 1	7.2: 1	7.0: 1	6.5: 1
Valve control:	One overhead camshaft with chain drive each		Two overhead camshafts each with steering wheel drive		One overhead camshaft with chain drive each
Cooling:	Air cooling (fan)		Air cooling (fan), cylinder heads with water cooling		Air cooling (fan)
Transmission:	5-speed gearbox, limited slip differential , rear-wheel drive			4-speed gearbox, limited slip differential, rear-wheel drive	5-speed gearbox, limited slip differential, rear-wheel drive
Brakes:	Disc brakes (internally ventilated)
Front suspension:	Wishbones with longitudinal thrust struts, anti-roll bar
Rear suspension:	One lower wishbone and one upper and one lower longitudinal thrust strut
Front suspension:	one progressive coil spring per wheel with gas pressure shock absorber
Rear suspension:	one progressive coil spring per wheel with gas pressure shock absorber
Body:	Aluminum space frame with plastic body
Track width front / rear:	1580/1510 mm	1530/1480 mm	1540/1515 mm
Wheelbase :	2400 mm	2410 mm		2400 mm	2410 mm
Tires rim:	VA: 265/565 × 15 on 10.5J × 15 HA: 340/600 × 15 on 15J × 15
Dimensions L × W × H:	4200 × 1980 × 1010 mm	4150 × 1930 × 1010 mm	4960 ×? ×? mm	4950 × 1920 × 1270 mm	4960 × 1920 × 1170 mm	4960 ×? ×? mm	4800 × 1990 × 1000 mm
Empty weight :	700 kg		780 kg				870 kg
Top speed:	350 km / h	360 km / h			350 km / h		360 km / h

literature

• Jürgen Barth, Bernd Dobronz: Porsche 936. The documentation of the racing classic . Motorbuch Verlag, Stuttgart 2015, ISBN 978-3-613-03756-4 .
• Jürgen Barth, Gustav Büsing: The big book of the Porsche types. Race car. Motorbuch Verlag, Stuttgart 2010, ISBN 978-3-613-03241-5 .
• Peter Schneider: Type compass Porsche. Racing and racing sports cars since 1948. Motorbuch Verlag, Stuttgart 2003, ISBN 3-613-02300-8 .
• Lothar Boschen, Jürgen Barth: The big book of Porsche types. Motorbuch Verlag, Stuttgart 1994, ISBN 3-613-01284-7 .

Web links

Commons : Porsche 936  - Collection of Pictures, Videos and Audio Files

Porsche database

• Porsche 936 Spyder on Porsche.com ( Memento from October 22, 2009 in the Internet Archive )
• Porsche 936/81 Spyder on Porsche.com ( Memento from October 22, 2009 in the Internet Archive )

Report on the Internet

• The Porsche 936 on Ultimatecarpage.com (English)

Individual evidence

1. ↑ ^{a b c} Dr. Ing.hc F. Porsche AG: 1976 - Porsche 936 Spyder. On: www.porsche.com/germany/ , archived from the original on October 22, 2009 ; Retrieved February 16, 2013 . 
2. ↑ ^{a b c} Dr. Ing.hc F. Porsche AG: 1981 - Porsche 936/81 Spyder. On: www.porsche.com/germany/ , archived from the original on October 22, 2009 ; Retrieved February 16, 2013 . 
3. ^ ^{A b c d} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 288.
4. ^ ^{A b c d e f} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 291.
5. ↑ ^{a b} Classicscars - website: race results and overall placements of the DRM 1982. At: www.classicscars.com , accessed on February 16, 2013 . 
6. ↑ ^{a b} Auto Zeitung - Internet site: Porsche 936 Turbo - Le Mans winner from 1977. (No longer available online.) On: www.autozeitung.de , July 2, 2011, archived from the original on March 22, 2012 ; Retrieved February 16, 2013 . 
7. ↑ Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 270.
8. ^ ^{A b c} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 273.
9. ↑ ^{a b c d e f g h} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 274.
10. ↑ ^{a b} Classicscars - Internet site: Racing results of the Sports Car World Championship 1976. From : www.classicscars.com , accessed on February 16, 2013 . 
11. ↑ ^{a b c d e f g h i j} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 302 and p. 303.
12. ↑ Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 277.
13. ↑ Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 276.
14. ^ ^{A b} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 278.
15. ^ ^{A b c d} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 279.
16. ^ ^{A b} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 280.
17. ^ ^{A b c} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 282.
18. ^ ^{A b} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 285.
19. ^ ^{A b c d} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 287.
20. ↑ Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 275.
21. ^ ^{A b} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 281.
22. ↑ Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 296.
23. ^ ^{A b c d} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 292.
24. ↑ Classicscars - Internet site: Le Mans race results 1976. From : www.classicscars.com , accessed on March 29, 2013 . 
25. ^ Classicscars - Internet site: Le Mans race results 1977. At: www.classicscars.com , accessed on March 29, 2013 . 
26. ^ Classicscars - Internet site: Le Mans race results 1978. At: www.classicscars.com , accessed on March 29, 2013 . 
27. ↑ Classicscars - website: race results and overall placements of the 1980 Interseries. At: www.classicscars.com , accessed on March 29, 2013 . 
28. ↑ Classicscars - Internet site: Race results and overall placements of the Interserie 1981. At: www.classicscars.com , accessed on March 29, 2013 . 
29. ^ Classicscars - Internet site: Le Mans race results 1981. At: www.classicscars.com , accessed on March 29, 2013 . 
30. ↑ Classicscars - Internet site: Racing results of the Sports Car World Championship 1982. At: www.classicscars.com , accessed on March 29, 2013 . 
31. ↑ Classicscars - Internet site: Racing results of the Sports Car World Championship 1983. At: www.classicscars.com , accessed on March 29, 2013 . 
32. ↑ Classicscars - Internet site: Race results of the DRM 1983. On: www.classicscars.com , accessed on March 29, 2013 . 
33. ↑ Classicscars - Internet site: Race results and overall placements of the Interserie 1982. On: www.classicscars.com , accessed on March 29, 2013 . 
34. ↑ Classicscars - Internet site: Race results of the Interserie 1984. At: www.classicscars.com , accessed on March 29, 2013 .