PORSCHE RACING HISTORY1981 - Mosport 6 Hours
16 August 1981 - Mosport Park, Canada
Rolf Stommelen & Harald Grohs win in a Porsche 935 M16
Overall - 1st, 3rd : GTX - 1st, 3rd : GTO - 3rd : GTU - 3rd
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 3 | Porsche 935 M16 | 930 890 0013 | GTX | Rolf Stommelen (D)/Harald Grohs (D) | Andial Meister Racing (USA) | 1st | 1st | 1st | 229 laps |
| 0 | Porsche 935 K3/80 | 000 00010 | GTX | Ted Field (USA)/Bill Whittington (USA) | Interscope IMSA Racing (USA) | 3rd | 3rd | 2nd | 222 laps |
| 09 | Porsche 935 K3 | 000 0009 | GTX | Preston Henn (USA)/Edgar Dören (D) | Preston Henn (USA) | 4th | 4th | 17th | 219 laps |
| 1 | Porsche 935 K3/80 | 000 00011 | GTX | John Fitzpatrick (GB)/Jim Busby (USA) | John Fitzpatrick Racing (GB) | 6th | 5th | 5th | 217 laps |
| 46 | Porsche 935 J | 000 00012 | GTX | Mauricio DeNarváez (COL)/Bob Garretson (USA) | De Narvaez (CO) | 7th | 6th | 30th | 215 laps |
| 84 | Porsche 935 M16 | 930 670 0171 | GTX | " Jamsal" (ES)/Eduardo Galdamez (ES) | Scorpio Racing (ES) | 10th | 7th | 19th | 206 laps |
| 5 | Porsche 935 K3/80 | 000 00013 | GTX | Skeeter McKitterick (USA)/Bob Akin (USA) | Bob Akin Racing (USA) | 12th | 8th | 8th | 205 laps |
| 79 | Porsche 924 Carrera GTR | WP0ZZZ93ZBS720006 | GTO | Tom Winters (USA)/Bob Bergstrom (USA) | Whitehall Capital Promotions Limited (USA) | 13th | 3rd | 24th | 203 laps |
| 07 | Porsche 924 Carrera GTR | WP0ZZZ93ZBS720005 | GTO | Ludwig Heimrath, Jr (CDN)/Ludwig Heimrath, Sr (CDN) | Heimrath Racing (CDN) | 15th | 4th | 15th | 186 laps |
| 17 | Porsche 935 M16 | 930 990 0032 | GTX | Pepe Romero (USA)/Diego Febles (PR) | Pepe Romero (USA) | 16th | 10th | 29th | 185 laps |
| 27 | Porsche 914/6 | 914 043 0188 | GTU | Peter Aschenbrenner (CDN)/Peter Tescher (CDN) | Alps Restoration (CDN) | 17th | 3rd | 32nd | 182 laps |
| 53 | Porsche 911 Carrera RSR | 006 00024 | GTO | Rudy Bartling (CDN)/Fritz Hochreuter (CDN)/Norm Ridgely (CDN) | Fritz Hochreuter (CDN) | 19th | 6th | 25th | 170 laps - DNF |
| 91 | Porsche 934 | 930 670 0167 | GTO | Chester Vincentz (USA)/Derek Bell (GB) | Electrodyne Racing (USA) | 21st | 8th | 23rd | 145 laps - DNF |
| 21 | Porsche 911 | GTU | Stephen Lax (CDN)/Herman Lansberg (CDN)/Peter Moennick (CDN) | Stephen Lax Racing (CDN) | 22nd | 4th | 33rd | 141 laps - Fatal Accident | |
| 57 | Porsche 914/6 | GTU | Robert Overby (USA)/Wayne Baker (USA) | Personalized Autohaus (USA) | 23rd | 5th | 26th | 139 laps | |
| 72 | Porsche 911 Carrera | GTO | Jean Kjoller (USA)/Jay Kjoller (USA) | Russell Porsche | 24th | 9th | 38th | 123 laps | |
| 30 | Porsche 935/81 | JR-001 | GTX | Gianpiero Moretti (I)/Bobby Rahal (USA) | Momo/Penthouse (I) | 26th | 11th | 10th | 105 laps - Accident |
| 22 | Porsche 914/4 | GTU | Wayne Baker (USA)/Robert Overby (USA) | Personalized Autohaus (USA) | 28th | 7th | 20th | 95 laps - DNF | |
| 18 | Porsche 935 JLP-3 | JLP-3 | GTX | John Paul, Jr. (USA)/John Paul Sr. (USA) | JLP Racing (USA) | 30th | 14th | 3rd | 41 laps - Accident Damage |
| 73 | Porsche 911 | GTU | Rick Bye (CDN)/Uli Bieri (CDN) | Hi-Fi Express | 33rd | 8th | 27th | 0 laps - DNF |
World Championship for Drivers and Makes IMSA - International Motor Sport Association
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