PORSCHE RACING HISTORY1981 - Road America 500 Miles
23 August 1981 - Road America, USA
Rolf Stommelen & Harald Grohs win in a Porsche 935 M16
Overall - 1st : GTX - 1st : GTO - 2nd : 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 | 2nd | 125 laps |
| 9 | Porsche 935 K3/80 | 009 00030 | GTX | Tom Gloy (USA)/Bob Garretson (USA) | Garretson Racing Style Auto Racing (USA) | 4th | 4th | 10th | 119 laps |
| 30 | Porsche 935/81 | JR-001 | GTX | Gianpiero Moretti (I)/Bobby Rahal (USA) | Momo/Penthouse (I) | 5th | 5th | 7th | 118 laps |
| 1 | Porsche 935 K3/80 | 000 00011 | GTX | John Fitzpatrick (GB)/Jim Busby (USA) | Fitzpatrick Racing (GB) | 6th | 6th | 6th | 118 laps |
| 0 | Porsche 935 K3/80 | 000 00010 | GTX | Ted Field (USA)/Bill Whittington (USA) | Interscope Racing (USA) | 7th | 7th | 8th | 111 laps |
| 22 | Porsche 914/4 | GTU | Wayne Baker (USA)/Robert Overby (USA) | Personalized Autohaus (USA) | 11th | 3rd | 27th | 106 laps | |
| 18 | Porsche 935 JLP-3 | JLP-3 | GTX | John Paul, Jr. (USA)/John Paul Sr. (USA) | JLP Racing (USA) | 13th | 8th | 1st | 104 laps - Engine |
| 26 | Porsche 911 Carrera RSR | 911 230 0030 | GTO | Tim Selby (USA)/Earl Roe (USA) | Roe/Selby Racing | 16th | 2nd | 45th | 103 laps |
| 79 | Porsche 924 Carrera GTR | WP0ZZZ93ZBS720006 | GTO | Tom Winters (USA)/Bob Bergstrom (USA) | Promotion Ltd. Whitehall Capital (USA) | 23rd | 5th | 33rd | 94 laps - Drive Shaft |
| 46 | Porsche 935 J | 000 00012 | GTX | Derek Bell (GB)/Mauricio DeNarváez (COL) | DeNarvaez Enterprises (CO) | 27th | 10th | 12th | 85 laps |
| 04 | Porsche 911 Carrera RSR | 911 560 9119 | GTO | Rene Rodriguez (USA)/Ernesto Soto (YV) | T & R Racing (USA) | 30th | 7th | 26th | 71 laps - DNF |
| 84 | Porsche 935 M16 | 930 670 0171 | GTX | Karen Erstad (USA)/Eduardo Galdamez (ES) | Scorpio Racing (ES) | 32nd | 11th | 31st | 66 laps |
| 5 | Porsche 935 K3/80 | 000 00013 | GTX | Skeeter McKitterick (USA)/Bob Akin (USA) | Bob Akin Motor Racing (USA) | 33rd | 12th | 16th | 62 laps - Engine |
| 09 | Porsche 935 K3 | 000 0009 | GTX | Danny Sullivan (USA)/Edgar Dören (D) | Thunderbird Swap Shop (USA) | 36th | 13th | 14th | 50 laps - Fuel Injection |
| 03 | Porsche 934 | 930 670 0162 | GTO | Rudy Bartling (CDN)/Werner Frank (USA) | Werner Frank (USA) | 38th | 12th | 22nd | 45 laps - DNF |
| 57 | Porsche 914/6 | GTU | Jeff Scott (USA)/David Finch (USA) | Personalized Autohaus | 41st | 14th | 42nd | 39 laps - DNF | |
| 17 | Porsche 935 M16 | 930 990 0032 | GTX | Joe Varde (USA)/Pepe Romero (USA) | Pepe Romero (USA) | 43rd | 15th | 20th | 36 laps - Wheel |
World Championship for Drivers and Makes IMSA - International Motor Sport Association
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