PORSCHE RACING HISTORYWilliam Vollery (CH)
1975
6 April 1975 - Dijon 800 Km - World Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 28 | Porsche 911 Carrera RSR | 911 460 9052 | GT | William Vollery (CH)/Roger Dorchy (F) | William Vollery | DNQ |
15 June 1975 - Le Mans 24 Hours - Non Championship Race
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 52 | Porsche 911 Carrera RSR | 911 360 0960 | GTS | William Vollery (CH)/Roger Dorchy (F)/Eric Chapuis (CH) | Écurie du Nord (F) | DNF | 29th | 93 laps - Valves |