Porsche 961
| Porsche | |
|---|---|
Porsche 961 IMSA-GTX with start number 203 in the Porsche Museum
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| 961 IMSA-GTX | |
| Production period: | 1986-1987 |
| Class : | race car |
| Body versions : | Coupe |
| Engines: |
Gasoline engine : 2.85 liters (499 kW) |
| Length: | 4380 mm |
| Width: | 1890 mm |
| Height: | 1260 mm |
| Wheelbase : | 2300 mm |
| Empty weight : | 1150 kg |
| Previous model | Porsche 935 |
| successor | Porsche 911 GT1 |
With the Porsche 961 , Porsche developed a racing car version of the Porsche 959 modified for circuit racing in the mid-1980s , which was to inherit the very successful 935 , but was never able to build on its successes.
development
At the end of 1985 (when development of the 959 was still in full swing), Porsche decided to build a one-off circuit version of the 959, which was very successful in rallying , on the basis of the WPOZZZ93ZFS0 10016 chassis . The vehicle was completed at the beginning of 1986 and shortly afterwards presented to the trade press as the 961 IMSA-GTX Coupé . The all-wheel drive permitted in the IMSA GTX class was adopted from the starting base 959 , as was the 2.847-liter twin-turbo engine from the Porsche 956 , whose boost pressure was increased from 0.8 to 1.25 bar for the 961. In addition, the Motronic was re-tuned, the map adapted and additional charge air cooling was achieved through more efficient and larger air coolers. The high-performance engine now had 500 kW at 7800 rpm and a maximum torque of 656 Nm at 5000 rpm. The circuit was taken from the 959 - albeit fundamentally revised. The six-speed gearbox , which passed the power on to the four drive wheels via a rigid through drive , also came from the base vehicle. The main differences to the 959 can be found in the body , with a larger rear wing that can be adjusted for racing , and some additional cooling air openings . The wheels of the 961, like those of the 959, were made of an aluminum alloy with magnesium , but the 961 was painted black.
Race inserts and racing successes
The racing debut of the unsponsored 961 in 1986 at the 24 Hours of Le Mans was very successful for Porsche, the car and the drivers René Metge and Claude Ballot-Léna with starting number 180. As the only participant in the IMSA GTX class , the car finished the race as class winner and in 7th place overall. The vehicle, homologated on the basis of the street version 959 , started from the 26th starting position. Porsche could also be pleased that only one other make was represented in the top ten. A record that has remained unbroken to this day. During the race, the vehicle reached top speeds of up to 330 km / h on the Mulsanne and was able to safely reduce its speed again thanks to the braking system adopted from the Group C racing car 956 .
However, the further development of the 961 should not proceed as one had expected at Porsche. The heavy and at higher speeds braking and tire-killing all-wheel drive was too disruptive. Bad aerodynamics (which among other things drive the fuel consumption , which is not exactly low in a racing car, even higher) and problems with the transmission did not make the situation more promising.
The consequences of these problems were drastic: At the 3-hour race in Daytona on October 26, 1986, this time in the GTP class with starting number 15 and starting from 29th place, 961 - driven by Günter Steckkönig and Kees Nierop - achieved only 11th place in his class and 24th overall.
The end
In June 1987 at the 24 Hours of Le Mans the car started for its third race. The 961, now with the starting number 203, covered in the colors of the sponsor Rothmans and driven by René Metge , Claude Haldi and Kees Nierop , could not finish the race because a fire broke out as a result of an accident caused by guest driver Nierop . Nierop switched on lap 199, shifted into 2nd gear after 6th and engaged the clutch . The result was an over-revving of the engine up to 15,000 rpm, immediate blocking of the engine as well as the transmission and all-wheel drive. As a result, despite the high speed, all four wheels suddenly came to a standstill, which is why Nierop hit the guardrails . The engine oil dripping on the turbocharger and exhaust pipes ignited, but Nierop was able to escape unharmed from the burning car.
Porsche then decided to stop any development work on the 961 and concentrate on the Indy project . Due to the half-hearted commitment of those involved and inconsistently tackled problems with the 961 (which were largely based on the technology largely adopted from the 959), the vehicle was ultimately never able to show what potential it really had.
The vehicle is now part of the permanent exhibition “Success Story: Porsche Motorsport” in the EFA Museum for German Automobile History in Amerang / Chiemgau.
Technical specifications
| Porsche 961: | Data |
|---|---|
| Engine: | 6-cylinder boxer engine with bi-turbocharging (four-stroke) (type 935/82) |
| Displacement: | 2847 cc |
| Bore × stroke: | 93 x 70.4 mm |
| Performance at 1 / min: | 500 kW (680 hp) at 7800 |
| Max. Torque at 1 / min: | 656 Nm at 5000 |
| Compression: | 8.1: 1 |
| Valve control: | two overhead camshafts ( DOHC ) |
| Cooling: | Air cooling (fan), cylinder heads with water cooling |
| Transmission: | 6-speed gearbox, all-wheel drive |
| Brakes: | internally ventilated disc brakes |
| Front suspension: | Independent suspension per wheel |
| Rear suspension: | Independent suspension per wheel |
| Front suspension: | one coil spring per wheel |
| Rear suspension: | one coil spring per wheel |
| Body: | Self-supporting body made of plastic and light metal |
| Track width front / rear: | 1522 mm / 1580 mm |
| Wheelbase : | 2300 mm |
| Tires / Wheels: | Magnesium wheels (VA: 235 × 45 VR17 / HA: 255 × 40 VR17) |
| Dimensions L × W × H: | 4380 × 1890 × 1260 mm |
| Empty weight : | 1150 kg |
| Top speed: | 330 km / h |
literature
- Jörg Austen: Porsche 911 rally and racing cars. The technical documentation. Motorbuch Verlag, Stuttgart 2005, ISBN 3-613-02492-6
- Peter Schneider: Type compass Porsche. Racing and racing sports cars since 1948. Motorbuch Verlag, Stuttgart 2003, ISBN 3-613-02300-8