The first of the eight Can-Am series races was held as usual in Canada at the Mosport Park. Mark Donohue qualified on pole but beside him was South African Jody Scheckter driving a Porsche 917/10 belonging to Vasek Polak Racing.
|"It's like riding a bicycle with an afterburner on the back. It's too fast on the straights and too slow in the corners. If it's wet tomorrow, they can get someone else to crash it!"
Polak was a major Southern California Porsche dealer originally from the Czech Republic.
Behind them were teammates George Follmer and Charlie Kemp driving Porsche 917/10s for the Royal Crown Cola sponsored Rinzler Motor Racing. Jackie Oliver driving a Shadow DN2 was down in 11th. At the start Scheckter dove in front only to be passed by Donohue
in exactly the same way. Coming up on a backmarker, Donohue found has path blocked and hit the back of the other car forcing him to pit to have the damaged nose piece of his car replaced. This put Scheckter in the lead before he was done in with a blown tire which put him into the guardrail. Charlie Kemp would assume the lead and win his first and last Can-Am race. Hans Wiedmer was 2nd, two laps down followed by Bob Nagel, another lap back.
The next race at Road Atlanta would consist of a 90 mile race divided into a forty mile race on Saturday added to a 50 mile race on Sunday. Donohue once again won Pole with Follmer joining him on the front row. Mosport's winner was involved in a testing accident where he suffered injuries to his back putting him out for this race. Donohue easily won on Saturday but suffered a fuel leak on Sunday allowing Follmer to win the combined race, Donohue 2nd and Jody Scheckter in 3rd.
Another race, another pole for Donohue at Watkins Glen. Qualifying 4th was David Hobbs driving a McLaren M20 for Roy Wood Racing. The race was split into two thirty-lap heats, both run on Sunday. This time Donohue's car ran without problems giving him commanding wins in both heats, while Follmer's turbocharger failed. Scheckter had issues with tire selection allowing Hobbs by for a fine 2nd place followed by the South African in 3rd. Charlie Kemp recovering from his injuries and wearing a back brace came in a painful 4th.
At Mid-Ohio both Follmer and Scheckter forced their cars past Donohue on the opening lap. The Porsche 917/30 finally passed both cars and began to pull away. Scheckter left the track trying to avoid a backmarker and damaged his suspension forcing him to eventually retire. In the second heat Donohue out dragged Follmer and that was the end of the race. Hurley Haywood would finish 3rd driving a Porsche 917/10 for Brumos Racing.
At the fifth round in Wisconsin's Road America the race was split into two heat with the first heat only counting for the starting grid in the second. Donohue won with Scheckter 2nd and Follmer in third. Donohue won at Edmonton with Follmer in 2nd and Oliver in a much improved Shadow in 3rd. Peter Bryant having moved from Autocoast was finally able to have some effect on the car's handling. Jody Scheckter was forced out of the race with a blow engine on lap 11.
At Laguna Seca in Monterey, California another win for the Porsche 917/30 but Jackie Oliver and the Shadow Dn2 were able to score their best finish in 2nd, finishing 3rd was Hurley Haywood.
Jody Scheckter who qualified 2nd had his clutch fail on lap 11. Follmer dropped out on lap 44 when his turbocharger failed.
The season ending race at Riverside and a final win for Mark Donohue, Roger Penske and his Porsche 917/30. Hurley Haywood driving for Brumos Racing finished 2nd in his Porsche 917/10 with Charlie Kemp 3rd. Many of the other leading cars including those driven by Follmer and Scheckter were forced to retire after clouting one or more of the old tire turn markers. The fact that these remain is simply inexcusable. Vic Elford driving the turbo-charged Shadow DN2 lasted all of one lap. Mark Donohue would run away with the Championship scoring 139 points to George Follmer's 62 points with Hurley Haywood's 47 points in 3rd.
All of the work with the factory in Germany to make the Porsche 917/10 and 917/30 complete racing cars had finally paid off in a race car that many considered the fastest race car ever built with which he would later set a new world closed-course speed record of 221.12 mph at the Talladega Speedway in 1975.
Donohue had planned to retire from driving at the end of the 1973 season only to come out of retirement for Penske's ill-fated Formula 1 project. Mark Donohue had come a long way from the time he was offered $50 per day to work for Roger Penske.