PORSCHE RACING HISTORYBob Zulkowski (USA)
1980
22 March 1980 - Sebring 12 Hours - World Challenge for Endurance Drivers
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 23 | Porsche 914/6 | 473 29 24107 | GTU | Bob Zulkowski (USA)/Dennis Brisken (USA)/Gary Nylander (USA) | Metalcraft Racing (USA) | 55th | 17th | 70th | 73 laps - DNF |
27 April 1980 - Riverside 5 Hours - World Challenge for Endurance Drivers
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 28 | Porsche 914/6 | 473 29 24107 | GTU | Bob Zulkowski (USA)/Bill Johnson (USA) | Metal Craft Racing (USA) | 39th | 15th | 57th | 67 laps |
5 July 1980 - Watkins Glen 6 Hours - World Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 23 | Porsche 914/6 | 473 29 24107 | Trans Am | Bob Zulkowski (USA)/Gary Pullyblank (CDN)/Bernie Storc (USA) | Metal Craft Racing (USA) | 26th | 11th | 30th | 74 laps - Electrical |