Grand Touring Prototype
There was an interesting movement happening in America. The Can-Am series. Here was a race car series that allowed for virtually unlimited sports prototypes to compete in sprint style races. Many major manufacturers which had been competing in Europe produced an effort for the series. It wasn’t all Richard Petty and Dodge Chargers driving in circles in the USA after all.
Can-Am utilized FIA Group 7 regulations which were essentially unlimited. Group 7 had been utilized in Europe, but to limited popularity and scope – mainly hillclimb racing and other smaller series. Parameters like displacement, engine aspiration, and aerodynamics were only limited by the sky. This was the Wild West all over again, but the governing body let it be. Can-Am was taking a completely anti-FIA approach of a totally un-homologated racing series. What resulted were some extreme vehicle concepts that took the lack of rules to the very edge, and even past it, namely from the Chaparral outfit. The 2J model was perhaps the ultimate example of what Group 7 rules could allow in a racing car. It was a twin-engined car, with the by-then usual big-block Chevrolet engine providing the driving force, and a tiny snowmobile engine powering a pair of fans at the back of the car. These fans, combined with the moveable Lexan skirts around the bottom of the car created a vacuum underneath the car, effectively providing the same level of downforce as the huge wings of previous vehicles, without the drag.
All good things come to an end eventually, so when the Mustang began to transform from a pony car icon into a piece of cheese, and the Japanese sports compact car rose in popularity, American racing was never going to be far from the chopping block. Ultimately, the Can-Am series was doomed by the depression in The United States and the energy crisis that followed. It folded in 1974, which sadly saw the 24 Hours of Daytona cancelled for that year. Aftermath of the fold was limited to a few smaller off shoot series with different regulations meant for closed wheel race car competition.
Meanwhile, over in Europe, with the dwindling popularity of the World Championship for Makes causing concern for FIA. Introduced was the World Championship for Sports Cars, a series tailor made for prototypes that started in 1976 but only lasted for two years. At this point, the entity that organized each running of the 24 Hours of Le Mans, ACO attempted to come up with a regulation framework that would encourage prototypes back to the famed race, but maintain an economical running structure. The ACO shot for the best of both worlds, and landed on the Grand Touring Prototype rules in the late 70’s after the flop of the World Championship for Sports Cars. This set of rules based around fuel consumption regulations would give rise to two different varieties of sports car racing that were widely considered to be a highlight in the history of the sport.