PORSCHE RACING HISTORYM. L. Speer (USA)
1981 : Mid-Ohio 500 km - 3rd in class
1 February 1981 - Daytona 24 Hours - World Championship for Drivers and Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 45 | Porsche 914/6 | 914 043 0593 | GTU | M. L. Speer (USA)/Dwight Mitchell (USA)/Ray Ratcliff (USA) | Autosport Technology (USA) | 13th | 7th | 58th | 581 laps |
30 August 1981 - Mid-Ohio 500 km - Non Championship Race
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 18 | Porsche 935 JLP-2 | 009 00043 | Gr.5 | Ray Ratcliff (USA)/M. L. Speer (USA) | JLP Racing (USA) | 9th | 3rd | 29th | 116 laps |
29 November 1981 - Daytona Finale 250 Miles - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 35 | Porsche 911 Carrera RSR | 911 460 9113 | GTO | M. L. Speer (USA)/Terry Wolters (USA) | 18th | 7th | 31st | 57 laps |