In the early 1980s, the Fédération Internationale du Sport Automobile (FISA) restructured motorsport classifications, creating Group B and Group C categories for the World Sports-Prototype Championship. Porsche developed the 956 for Group C, and subsequently began work on a Group B car. An initial prototype, named the Porsche Gruppe B, appeared in 1983, with plans for production and customer sales mirroring the approach taken with the 956.
By 1985, when the Gruppe B concept launched as the production 959, FISA had revised Group B regulations to better suit the World Rally Championship. This led Porsche to abandon plans for multiple customer cars for sports car racing, but development continued on a single, factory-run car to utilize the project’s advancements. This car became known as the 961, built on 959 chassis No. 10016.
The 961 retained many features of the 959 road car, most notably its four-wheel drive system—uncommon in sports car racing but permitted under Group B rules. The system was modified to favor rear-wheel power distribution compared to the 959’s balanced setup. Driver-adjustable dampers and suspension were replaced with a racing-specific unit, prioritizing reliability for endurance racing.
The engine was a Porsche Type-935 unit, a twin-turbocharged engine also used in the 956 and 962C. This allowed the 961 to run at a higher boost level, producing a peak output of 680 hp (510 kW). Brakes were sourced from the 962C, while lighter body panels reduced the car’s weight to 1,150 kg (2,540 lb). Modified rear wings and front fascia were added to increase downforce, and Dunlop provided the tyres.
Due to Porsche not having produced enough 959s to meet Group B homologation requirements in 1986, the 961 was classified under the International Motor Sports Association’s GTX class.
The 961 first appeared at the May test for the 1986 24 Hours of Le Mans, setting the tenth fastest lap time with René Metge at the wheel. This time was quicker than the BMW M1 in the Group B category and faster than several Group C prototypes. At the race in June, Metge and Claude Ballot-Léna qualified the car 26th, and ultimately finished seventh, 47 laps behind the winning factory 962C.
Later in 1986, the 961 was entered in the final round of the Camel GT Championship at Daytona International Speedway. Reclassified as a GTP car, the 961 was driven by Kees Nierop and Günter Steckkönig. The car struggled with the banked turns of the circuit, experiencing tyre blowouts at high speed and finishing 24th.
Porsche continued to develop the 961 for the 1987 season, repainting it in Rothmans colors to match the factory 962Cs. However, performance decreased, with the car achieving only the 16th fastest lap in the May test session. René Metge and Claude Haldi were initially assigned as drivers, later joined by Kees Nierop after his 962C was damaged in qualifying. During the race, Nierop crashed the car after a mis-shift, causing a fire as he attempted to return to the pit lane, leading to the car’s retirement.
Following this incident, and lacking a suitable championship in which to compete, the 961 project was canceled. The repaired car is now on display at the Porsche Museum in Stuttgart, Germany.