PORSCHE RACING HISTORYTom Alan Marx (USA)
1979
22 April 1979 - Riverside 6 Hours - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 31 | Porsche 911 Carrera RSR | GTO | Tom Alan Marx (USA)/Marc Rothman (USA)/Michael Hammond (USA) | RSR Associates (USA) | 50th | 12th | 29th | 13 laps - DNF |
29 April 1979 - Laguna Seca 100 Miles - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 31 | Porsche 911 Carrera RSR | GTO | Tom Alan Marx (USA) | RSR Associates (USA) | 25th | 14th | 22nd | 3 laps - DNF |