PORSCHE RACING HISTORYChester Vincentz (USA)
1981 : Watkins Glen 6 Hours - 1st in class : Mid-Ohio 500 km - 3rd in class
12 July 1981 - Watkins Glen 6 Hours - World Championship for Drivers and Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 91 | Porsche 934 | 930 670 0167 | GTO | Chester Vincentz (USA)/Lance Van Every (USA)/John Wood (USA) | Electrodyne, Inc. (USA) | 7th | 1st | 20th | 156 laps |
16 August 1981 - Mosport 6 Hours - World Championship for Drivers and Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 91 | Porsche 934 | 930 670 0167 | GTO | Chester Vincentz (USA)/Derek Bell (GB) | Electrodyne Racing (USA) | 21st | 8th | 23rd | 145 laps - DNF |
30 August 1981 - Mid-Ohio 500 km - Non Championship Race
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 91 | Porsche 934 | 930 670 0167 | Gr.4 | Chester Vincentz (USA)/Jeff Wood (USA) | Electrodyne (USA) | 7th | 3rd | 57th | 117 laps |