This is the best thing you will watch today. This documentary shows the debut of the Porsche 917 at Mosport in 1972. The car was far afield of what most fans were used to seeing in the series and it would ultimately be the race car that broke the half decade long dominance of the McLaren team on the Can-Am series. While Donohue did not win the championship, his teammate George Folder, also in a 917 did. These cars used (to start) a turbocharged 12-cylinder engine that made about 900hp. By the time the 917 had evolved to its eventual insane height, it had a 1,500hp engine in what was basically the same chassis.
1972 was about the time that Can-Am peaked in the US and Canada. By the time the 1974 season rolled around the crowds and most of the big money had moved on. It was one of the greatest experiments in racing history and showed just how insane that things could get if professional racers were given a rule book that basically only specified that their cars had four tires. After that, it was virtually wide open. Fans were used to the thundering noise of big block V8s powering the cars so the weird scream of a Porsche V12 was an anomaly at first and then a sign of the apocalypse for said V8 engines after that.
As you will see, this debut did not go exactly according to plan but the message was sent and you had to think that many of the other teams knew the writing was on the wall after this. The car was a monster and it was basically a monster in its baby stages here. The chassis had been developed in European racing but with huge power on American soil, it proved to be dominant.