You might first want to see all the modifications of the Porsche 917
Porsche 917/20 Le Mans
Premiere: April 17, 1971 Le Mans test day
Engine: 4.9F12 441 kW 404 lb-ft 550 Nm
The 917/20 was a one-off aerodynamic research study conducted by an external aerodynamics specialist SERA-CD (Société d’Etudes et de Réalisations Automobiles - Charles Deutsch).
The wheelbase and track were kept the same, but the body was made wider. Its rear end was something between the short- and longtail. They wanted to achieve the downforce and stability of the shorttail 917 and the smaller drag and the top speed of the longtail 917.
The idea to paint it like a pig came from the Porsche design manager Anatole "Tony" Lapine. Was it because how he saw the SERA-designed 917? Anyway, the livery was so unexpected that it became famous just because of that. And the car even didn't finish the race.