PORSCHE RACING HISTORYJim Busby (USA)
1981 : Riverside 6 Hours - 1st overall : Mid-Ohio 500 km - 2nd overall
1 February 1981 - Daytona 24 Hours - World Championship for Drivers and Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 935 K3/80 | 000 00011 | GTX | John Fitzpatrick (GB)/Jim Busby (USA)/Bob Wollek (F) | Kremer Racing (D) | 48th | 17th | 2nd | 167 laps - Engine |
21 March 1981 - Sebring 12 Hours - World Championship for Drivers and Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 935 K3/80 | 000 00011 | GTX | John Fitzpatrick (GB)/Jim Busby (USA) | John Fitzpatrick Racing (GB) | 41st | 12th | 1st | 129 laps - Driveshaft |
26 April 1981 - Riverside 6 Hours - World Championship for Drivers and Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 935 K3/80 | 000 00011 | GTX | John Fitzpatrick (GB)/Jim Busby (USA) | John Fitzpatrick Racing (GB) | 1st | 1st | 2nd | 199 laps |
12 July 1981 - Watkins Glen 6 Hours - World Championship for Drivers and Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 11 | Porsche 935 K3/80 | 000 00011 | Gr.5 | John Fitzpatrick (GB)/Jim Busby (USA) | John Fitzpatrick Racing (GB) | 4th | 4th | 13th | 160 laps |
16 August 1981 - Mosport 6 Hours - World Championship for Drivers and Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 935 K3/80 | 000 00011 | GTX | John Fitzpatrick (GB)/Jim Busby (USA) | John Fitzpatrick Racing (GB) | 6th | 5th | 5th | 217 laps |
23 August 1981 - Road America 500 Miles - World Championship for Drivers and Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 935 K3/80 | 000 00011 | GTX | John Fitzpatrick (GB)/Jim Busby (USA) | Fitzpatrick Racing (GB) | 6th | 6th | 6th | 118 laps |
30 August 1981 - Mid-Ohio 500 km - Non Championship Race
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 935 K3/80 | 000 00011 | Gr.5 | John Fitzpatrick (GB)/Jim Busby (USA) | John Fitzpatrick Racing (GB) | 2nd | 2nd | 7th | 129 laps |