PORSCHE RACING HISTORY1983 - Riverside 6 Hours
24 April 1983 - Riverside International Raceway, USA
John Fitzpatrick, David Hobbs & Derek Bell win in a Porsche 935 K4
Overall - 1st, 3rd : GTP - 1st, 3rd : GTO - 1st On lap 95 Rolf Stommelen driving the John Fitzpatrick entered Porsche 935, who had just taken over the car from Derek Bell and was running in second place when the rear wing broke due to mechanical failure at 190 mph (310 km/h). The car became uncontrollable, slammed against a concrete wall, somersaulted and caught fire. Stommelen died of head injuries.
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 2 | Porsche 935 K4 | K4-01 | GTP | John Fitzpatrick (GB)/David Hobbs (GB)/Derek Bell (GB) | John Fitzpatrick (GB) | 1st | 1st | 4th | 196 laps |
| 46 | Porsche 935/81 | JR-001 | GTP | Bob Wollek (F)/Mauricio DeNarváez (COL) | DeNarvaez Enterprises (CO) | 3rd | 3rd | 5th | 192 laps |
| 9 | Porsche 934 | 009 00030 | GTO | Wayne Baker (USA)/Jim Mullen (USA)/Kees Nierop (CDN) | Personalized Autohaus (USA) | 5th | 1st | 18th | 181 laps |
| 5 | Porsche 935 K3/80 | 000 00013 | GTP | Bob Akin (USA)/Dale Whittington (USA) | Bob Akin Motor Racing (USA) | 7th | 5th | 16th | 176 laps |
| 56 | Porsche 911 Carrera | 911 210 0224 | GTO | Rick Borlase (USA)/Michael Hammond (USA) | Rick Borlase | 14th | 5th | 45th | 166 laps |
| 08 | Porsche 911 | GTU | Peter Jauker (USA)/Gary Auberlen (USA)/Adrian Gang (USA) | Speedy Porsche Racing | 17th | 6th | 52nd | 160 laps | |
| 0 | Porsche 911 Carrera RSR | GTO | Kikos Fonseca (CR)/" Jamsal" (ES) | Latino Racing | 18th | 6th | 42nd | 159 laps | |
| 70 | Porsche 911 | GTU | Brent Regan (USA)/Larry Chmura (USA)/Jon Koobation (USA) | Brent Regan | 19th | 7th | 53rd | 158 laps | |
| 6 | Porsche 935 K3 | 000 0009 | GTP | Michael Andretti (USA)/A. J. Foyt (USA)/Mario Andretti (USA)/Preston Henn (USA) | PPG Industries (USA) | 20th | 7th | 9th | 154 laps - DNF |
| 35 | Porsche 911 Carrera RSR | 911 460 9113 | GTO | Al Leon (USA)/Wayne Pickering (USA)/Paul Gilgan (USA) | Pegasus Racing | 21st | 7th | 44th | 145 laps |
| 36 | Porsche 924 Carrera GTR | GTU | Jim Busby (USA)/Ron Grable (USA) | Herman Miller Porsche Audi (USA) | 24th | 8th | 41st | 136 laps | |
| 49 | Porsche 911 Carrera RSR | 12803002 | GTO | Bob Copeman (USA)/Jerry Jolly (USA) | Copeman Racing (USA) | 26th | 9th | 49th | 132 laps |
| 31 | Porsche 911 Carrera RSR | GTO | Tom Alan Marx (USA)/Dennis Lanfre (USA)/Connie Fern (USA) | RSR Associates (USA) | 30th | 12th | 47th | 105 laps - DNF | |
| 12 | Porsche 935/81 | JR-002 | GTP | Derek Bell (GB)/Rolf Stommelen (D) | John Fitzpatrick (GB) | 32nd | 10th | 2nd | 94 laps - Fatal Accident |
| 09 | Porsche 935 L | 935 L | GTP | A. J. Foyt (USA)/Mario Andretti (USA)/Bill Whittington (USA) | PPG Industries (USA) | 37th | 11th | 10th | 81 laps - DNF |
| 79 | Porsche 924 Carrera GTR | WP0ZZZ93ZBS720006 | GTU | Tom Winters (USA)/Bob Bergstrom (USA) | Whitehall-Promotions Racing (USA) | 41st | 13th | 30th | 56 laps - DNF |
| 58 | Porsche 924 Carrera GTR | WP0ZZZ93ZBS720011 | GTU | Deborah Gregg (USA)/Kathy Rude (USA) | Brumos Racing (USA) | 43rd | 14th | 34th | 48 laps - DNF |
| 50 | Porsche 935 K3/80 | 000 00010 | GTP | George Dyer (USA)/Greg Pusey (USA) | Drax Racing | 44th | 13th | 14th | 46 laps - DNF |
| 07 | Porsche 911 Carrera | GTU | Chuck McConnell (USA)/Richard Woodbury (USA)/Bruce Campbell (USA) | Beverly Hill Porsche Audi (USA) | 48th | 16th | 54th | 30 laps | |
| 24 | Porsche 935 JLP-2 | 009 00043 | GTP | M. L. Speer (USA)/Ken Madren (USA) | Pegasus III Racing (USA) | 49th | 16th | 20th | 29 laps - DNF |
| 53 | Porsche 911 Carrera | GTO | Steve Michaelson (USA) | Nardi Motors | 56th | 19th | 48th | 5 laps - DNF |
IMSA - International Motor Sport Association
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