When Ken Tyrrell, the team's owner, became disenchanted with the poor performance of the March chassis during the 1970 season, he decided he would design and build his own car. He employed Derek Gardner to design it in secret at his own house. The project, codenamed "SP", which meant "Special Project", cost Tyrrell over £22,000 of his own money. The resulting car named Tyrrell 001 made its debut at Oulton Park in a non-championship race.
After the season had finished, Gardner redesigned some sections of the car, altering the airbox, remodelling the nose section, lengthening the wheelbase and slightly narrowing the monocoque. The redesigned car became known as the 002 and 003, which were chassis numbers given to each of the cars made for the 1971 season. The team also switched tyre supplier to Goodyear after Dunlop withdrew from F1.