Porsche 909 Bergspyder

Porsche
Porsche 909 Bergspyder in the new Porsche Museum (2009)
909
Production period:	1968
Class :	race car
Body versions :	Monoposto
Engines:	Otto engine : 2.0 liters (202 kW)
Length:	3448 mm
Width:	1800 mm
Height:	710 mm
Wheelbase :	2264 mm
Empty weight :	430 kg
Previous model	Porsche 910

The Porsche 909 Bergspyder was a racing car from Porsche KG , which was specially developed for the European Hill Climb Championship in 1968 . With the very light car, Porsche pursued the goal of winning the championship title for the third time in a row after 1966 and 1967.

The 909 Bergspyder was only used in two races. Nevertheless, Porsche reached the goal and was able to celebrate the overall victory in the European Championships in 1968 with Gerhard Mitter , who drove a Porsche 910 Bergspyder in the races .

development

Porsche began developing the 909 under the leadership of the then head of development, Ferdinand Piëch , because the Porsche 910 Bergspyder used in the previous year was very difficult to drive due to constant modifications and the main competitor Ferrari had announced a new racing car for the 1968 European hill climb championship racing season .

Only two vehicles of the Porsche 909 were produced.

Vehicle characteristics

body

Porsche 909 on a demonstration lap on the Nürburgring (1981)

The body of the 909 largely corresponded to that of the 910 Bergspyder. It was made of plastic and screwed to the lightweight aluminum tubular mesh frame. The open cockpit had two seats and was accessible via two small doors from the left and right sides of the vehicle.

The bow and stern could each be removed from the tubular space frame as a complete unit. The bow had two small discs on the left and right to increase the air pressure on the front axle while driving. At the stern on the upper outer edges there were two movable flaps that were controlled by the wheel suspension.

The engine was placed far in the middle of the vehicle and the gearbox was installed in front of the rear axle between the engine and limited-slip differential in order to achieve the most neutral driving behavior possible. Due to the motor arrangement, the driver's seat had to be mounted almost above the front axle.

The 909 Bergspyder was extremely light with an unladen weight of 430 kg (375 kg dry weight ) thanks to the body and vehicle components that were consistently designed for lightweight construction . To achieve this, the developers sometimes used unusual materials and techniques. Instead of a conventional fuel tank with a fuel pump , a very light 15 liter gasoline pressure accumulator made of titanium was used. The resistors for the ignition system were attached to light balsa wood .

landing gear

The racing car had independent suspension with wishbones at the front and rear and longitudinal struts at the front and longitudinal struts at the rear. For the vehicle suspension, coil springs with hydraulic telescopic shock absorbers were used all around. The front springs were made of titanium. The braking system worked hydraulically. The brake discs were available in two versions. In addition to brake discs made of gray cast iron, those made of the very light beryllium were also used. Since the beryllium brake discs were very expensive to manufacture, only one vehicle was fitted with them.

Wide wheels on both axles provided power transmission to the road. The 13-inch cast light alloy wheels were 8 inches wide on the front axle and 13 inches wide on the rear axle. Tires in the dimensions 4.75 / 10.00-13 at the front and 6.00 / 12.00-13 at the rear were mounted on it.

engine and gears

In the 909 Bergspyder, Porsche installed an air-cooled eight-cylinder boxer engine with a displacement of 2 liters of the type 771. This engine had already been used in the Porsche 910 Bergspyder and had been tested in racing. In the 909 the engine delivered a maximum of 202 kW (275 hp) at 9000 rpm and thus around 3.7  kW (5  hp ) more than in the 910. This increase in output resulted from the increase in the engine speed limit by 200 rpm and an increase in compression of 10.4: 1 to 10.5: 1.

As gasoline storage and supply Porsche used for weight reasons a slight 15-liter accumulator from titanium . The titanium spherical tank contained a rubber bladder inside, which was pressurized to 10 bar before the start and which maintained the pressure in the fuel system during the race. In practice, the accumulator turned out to be less than optimal for use with the engine.

With the five-speed manual transmission, the racing car reached a top speed of around 250 km / h. In order to prevent the rear wheels from spinning on one side, a multi- disc limited slip differential was installed.

Racing history

With the 909 Bergspyder, Porsche entered the racing car class of the European Hill Climb Championship in 1968. Due to the short development time, the car could hardly be tested. The two Porsche works drivers Gerhard Mitter and Rolf Stommelen drove the new Bergspyder in training for the two hill climb races on Gaisberg (September 8th) and Mont Ventoux (September 22nd). While Mitter opted for the older, but tried and tested Porsche 910 Bergspyder, Stommelen started with the 909.

The later championship winner Gerhard Mitter won in both races. Rolf Stommelen came third on the Gaisberg and second on Mont Ventoux due to engine problems.

After the two races, the Porsche 909 Bergspyder was no longer used. However, it later served as a model for the development of the Porsche 908/03 .

Technical specifications

The Porsche 909 was produced and used in 1968 in the following version:

Porsche 909	Data
Engine:	8-cylinder boxer engine (four-stroke)
Displacement:	1991 cc
Bore × stroke:	76.0 x 54.6 mm
Performance at 1 / min:	202 kW (275 hp) at 9000
Max. Torque at 1 / min:	202 Nm at 7100
Compression:	10.5: 1
Valve control:	Two overhead camshafts each, vertical shaft drive
Cooling:	Air cooling (fan)
Transmission:	5-speed gearbox, limited slip differential, rear-wheel drive
Brakes:	Dual circuit disc brakes
Front suspension:	individually on double wishbones with longitudinal tension struts
Rear suspension:	individually on double wishbones with longitudinal thrust struts
Front suspension:	Coil springs with hydraulic telescopic shock absorbers
Rear suspension:	Coil springs with hydraulic telescopic shock absorbers
Body:	open plastic body with aluminum tubular space frame
Track width front / rear:	1470/1464 mm
Wheelbase :	2264 mm
Tires / Wheels:	VA: 4.75 / 10.00-13 on 8J × 13 HA: 6.00 / 12.00-13 on 12J × 13
Dimensions L × W × H:	3448 × 1800 × 710 mm
Empty weight :	430 kg
Top speed:	approx. 250 km / h

literature

• Jürgen Barth, Gustav Büsing: The big book of the Porsche types. Race car. Motorbuch Verlag, Stuttgart 2010, ISBN 978-3-613-03241-5 .

Web links

Commons : Porsche 909 Bergspyder  - Collection of pictures, videos and audio files

Porsche database

• Porsche 909 Bergspyder on Porsche.com ( Memento from March 23, 2009 in the Internet Archive )

Report on the Internet

• Autoleben - "Piëch and Porsche 909: Meet the Extreme" on Auto, Motor und Sport.de

Individual evidence

1. ↑ ^{a b c d e f g h} Auto, Motor und Sport: Piëch and Porsche 909 - Meeting of extremes. From: www.auto-motor-und-sport.de , April 17, 2007, accessed on December 8, 2012 . 
2. ↑ ^{a b c d e f g} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 141.
3. ↑ Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 168 and p. 169.
4. ↑ ^{a b} Dr. Ing.hc F. Porsche AG: 1968 - Porsche 909 Bergspyder. On: www.porsche.com/germany/ , archived from the original on March 23, 2009 ; Retrieved December 8, 2012 . 
5. ^ ^{A b c d e f} Jürgen Barth, Gustav Büsing: The great book of the Porsche types. Race car. P. 142.
6. ↑ Euromontagna - website: European Hill-Climb Championship. From: www.euromontagna.com , accessed December 8, 2012 .