PORSCHE RACING HISTORYBill Koll (USA)
1978 : Sebring 12 Hours - 3rd in class : Brainerd 100 Miles - 3rd in class
18 March 1978 - Sebring 12 Hours - World Challenge for Endurance Drivers
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 62 | Porsche 914/6 | 914 043 0593 | GTU | Bill Koll (USA)/David Hamren (USA)/Dennis Sherman (USA) | William J. Koll (USA) | 10th | 3rd | 53rd | 209 laps |
2 April 1978 - Talladega 6 Hours - World Challenge for Endurance Drivers
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 62 | Porsche 914/6 | 914 043 0593 | GTU | Bill Koll (USA)/David Hamren (USA) | William Koll (USA) | 11th | 4th | 32nd | 148 laps |
18 June 1978 - Brainerd 100 Miles - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 62 | Porsche 914/6 | 914 043 0593 | GTU | Bill Koll (USA) | William Koll (USA) | 18th | 3rd | 22nd | 29 laps |
4 July 1978 - Daytona 250 Miles Paul Revere - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 62 | Porsche 914/6 | 914 043 0593 | GTU | Bill Koll (USA) | William Koll (USA) | 22nd | 8th | 48th | 57 laps |