PORSCHE RACING HISTORYJo Siffert (CH)
1971 : Buenos Aires 1000 km - 1st overall : Sebring 12 Hours - 3rd in class : Brands Hatch 1000 km - 3rd overall, 1st in class : Le Mans Test - 2nd overall : Le Mans Test - 3rd overall : Monza 1000 km - 2nd overall : Spa 1000 km - 2nd overall : Nürburgring 1000 km - 2nd overall : Watkins Glen 6 Hours - 2nd overall, 1st in class : Can-Am Watkins Glen - 3rd : Can-Am Mid-Ohio - 2nd : Can-Am Road America - 2nd
10 January 1971 - Buenos Aires 1000 km - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 30 | Porsche 917 K | 917-014 | S | Jo Siffert (CH)/Derek Bell (GB) | J. W. Automotive (GB) | 1st | 1st | 3rd | 165 laps |
31 January 1971 - Daytona 24 Hours - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 917 K | 917-004 | S | Jo Siffert (CH)/Derek Bell (GB) | J. W. Automotive Engineering (GB) | DNF | 4th | 113 laps - Engine |
20 March 1971 - Sebring 12 Hours - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 917 K | 917-031 | S | Jo Siffert (CH)/Brian Redman (GB) | J. W. Automotive Engineering Ltd. (GB) | 5th | 3rd | 6th | 244 laps |
4 April 1971 - Brands Hatch 1000 km - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 6 | Porsche 917 K | 917-014 | S5.0 | Jo Siffert (CH)/Derek Bell (GB) | John Wyer Automotive (GB) | 3rd | 1st | 3rd | 235 laps |
18 April 1971 - Le Mans Test - Non Championship Race
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 17 | Porsche 917 K | 917-052 | S5.0 | Jo Siffert (CH)/Derek Bell (GB)/Jackie Oliver (GB) | J. W. Automotive Engineering (GB) | 2nd | 2nd |
18 April 1971 - Le Mans Test - Non Championship Race
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 18 | Porsche 917 K | 917-016 | S5.0 | Jackie Oliver (GB)/Jo Siffert (CH)/Derek Bell (GB) | J. W. Automotive Engineering (GB) | 3rd | 3rd |
18 April 1971 - Le Mans Test - Non Championship Race
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 20 | Porsche 917/20 | 717/20-001 | S5.0 | Jo Siffert (CH)/Willi Kauhsen (D) | Martini International Racing Team | 5th | 5th |
25 April 1971 - Monza 1000 km - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 917 K | 917-004 | S5.0 | Jo Siffert (CH)/Derek Bell (GB) | J. W. Automotive (GB) | 2nd | 2nd | 7th | 171 laps |
9 May 1971 - Spa 1000 km - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 20 | Porsche 917 K | 917-014 | S5.0 | Jo Siffert (CH)/Derek Bell (GB) | J. Wyer (GB) | 2nd | 2nd | 1st | 71 laps |
16 May 1971 - Targa Florio - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 7 | Porsche 908/03 | 908/03-010 | P3.0 | Brian Redman (GB)/Jo Siffert (CH) | J. W. Automotive Engineering (GB) | DNf | 7th | 0 laps - Accident/Fire |
30 May 1971 - Nürburgring 1000 km - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 908/03 | 908/03-013 | P3.0 | Pedro Rodríguez (MEX)/Jo Siffert (CH) | J. W. Automotive Engineering (GB) | 2nd | 2nd | 6th | 44 laps |
30 May 1971 - Nürburgring 1000 km - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 2 | Porsche 908/03 | 908/03-012 | P3.0 | Jo Siffert (CH)/Derek Bell (GB) | J. W. Automotive Engineering (GB) | DNF | 7 laps - Chassis |
13 June 1971 - Le Mans 24 Hours - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 17 | Porsche 917 L | 917-045 | S5.0 | Jo Siffert (CH)/Derek Bell (GB) | John Wyer Automotive Engineering (GB) | DNF | 3rd | 240 laps - Transmission |
24 July 1971 - Watkins Glen 6 Hours - International Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 917 K | 917-014 | S | Jo Siffert (CH)/Gijs van Lennep (NL) | J. W. Automotive Engineering (GB) | 2nd | 1st | 2nd | 277 laps |
25 July 1971 - Can-Am Watkins Glen - Can-Am - Canadian-American Challenge Cup
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 20 | Porsche 917/10 | 917/10-002 | Jo Siffert (CH) | Vasek Polak Racing | 3rd | 9th | 80 laps |
22 August 1971 - Can-Am Mid-Ohio - Can-Am - Canadian-American Challenge Cup
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 20 | Porsche 917/10 | 917/10-002 | Jo Siffert (CH) | STP Porsche Audi | 2nd | 4th | 78 laps |
29 August 1971 - Can-Am Road America - Can-Am - Canadian-American Challenge Cup
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 20 | Porsche 917/10 | 917/10-002 | Jo Siffert (CH) | STP Porsche Audi | 2nd | 6th | 49 laps |
12 September 1971 - Can-Am Donnybrooke - Can-Am - Canadian-American Challenge Cup
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 20 | Porsche 917/10 | 917/10-002 | Jo Siffert (CH) | STP Porsche Audi | 5th | 8th | 69 laps |
26 September 1971 - Can-Am Edmonton - Can-Am - Canadian-American Challenge Cup
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 20 | Porsche 917/10 | 917/10-002 | Jo Siffert (CH) | STP Porsche Audi | 4th | 7th | 78 laps |
17 October 1971 - Can-Am Laguna Seca - Can-Am - Canadian-American Challenge Cup
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 20 | Porsche 917/10 | 917/10-002 | Jo Siffert (CH) | STP Porsche Audi | 5th | 7th | 88 laps |