| 1980 | Abandono | 69 | Porsche 935 K3 | Bob Akin/Paul Miller/Ralph Kent-Cooke |
| 1981 | 6º (2º IMSA/GTX) | 42 | Porsche 935 K3 | Anny Charlotte Verney/Bob Garretson/Ralph Kent-Cooke |
| 1982 | Abandono | 17 | Lola T 610 | Brian Redman/Ralph Kent-Cooke/Jim Adams |
| 1983 | Abandono | 20 | Lola T 610 | Ralph Kent-Cooke/Jim Adams/Francois Servanin |
(Estados Unidos da América) 