A sports prototype, the McLaren M20 was developed by McLaren for the 1972 season of the Canadian-American Challenge Cup. The M20 Can-Am was constructed around the 'coke bottle' platform with a very low polar movement chassis while the vehicle's mass was concentrated within the wheelbase. The body was constructed of McLaren fiberglass while the engine was an 8.1-liter Chevrolet V8 fuel injected steadied on the rear of the tub. The 100-inch wheelbase extended 2 inches from the M8F specifications.
The McLaren M20 served as a replacement for the team's 1971 M8Fs though it later became the last Can-Am design created by McLaren before the team left the series after failing to secure the 1972 championship title. One of the team's primary goals when designing the replacement for the M8Fs was to improve the cooling structure of the vehicles in order to give their racers more comfort during the races.
Much like earlier McLaren sports vehicles, the M8F featured a larger radiator that was mounted in the front of the car where the air was drawn from openings in the nose and exited upwards over the open cockpit. The designers, Tyler Alexander and Gordon Coppuck came up with a solution to this heat problem which utilized two radiators, one each mounted on either side of the cockpit and drew air from the side of the bodywork. Decreasing fatigue on the drivers, hot air that exited the radiator no longer passed over the cockpit.
McLaren's designers were not free to redesign the nose for better aerodynamic efficiency with the radiator that was no longer found in the nose of the vehicle. Increasing the downforce on the front end of the vehicle resulted in the addition of an adjustable airfoil between the front wheel fenders which led to increased grip while cornering. The fuel tanks were also redesigned inside the car to make room for the new radiator design. Designed to flow from the outward tanks into the central tank to that fuel burned off during the race and didn't affect the weight distribution of the vehicle, the new tanks for the M20 were compacted around the cockpit.
The McLaren designers once again used a Chevrolet V8 engine which produced approximately 750 hp. The engine was mated to a Hewland Mk II gearbox that was mounted behind the engine. Similar to the M8F, the bodywork was fiberglass and was joined to the aluminum chassis which maintained the 'Coke bottle' design but with the addition of ducting on the side to feed the radiators. The brakes of the M20 were developed in conjunction with Lockheed. Grooves were machined into the discs to prevent out-gassing and improved on the recently cross-drilled brakes from the earlier season. Goodyear continued on as the team's official tire supplier.
There were three chassis build. At Mosport Park in 1972, the two new McLaren M20s debuted during the inaugural round of the 1972 season. Chassis 2 was the car for Denny Hulme and chassis 3 was for Peter Revson. In the Road Atlanta race, Hulme had an accident, completely destroying the car. His replacement was chassis 1.He won the next race!
But in 1972, the Penske Porsche with driver George Follmer were too strong and won the championship. Hulme was second and Revson sixth.
As McLaren decided to incest in other racing series, they sold the M20.
Chassis 1 was sold to the German Felder Racing Team for driver Helmut Kelleners who utilized it in the European Interserie championship up until 1973. After that it was owned by different drivers. As of 2010, the car should be in the UK.
Here at the Norisring 1973
Chassis 2 was rebuilt by Team McLaren and sold to Commander Motor homes in 1973. Commander turbocharged the car and ran it at Laguna Seca 1974. It was in the National Transportation Museum - Reno in 1999.
Chassis 3 was purchased for driver David Hobbs by Roy Woods Racing to continue campaigning in Can-Am, meanwhile, Fred Corbett purchased a vehicle originally for Mario Andretti who eventually was replaced by John Cannon. To better compete with Porsche's 917/30, Corbett's M20 was modified to add a turbocharger.
