In 1973, Ralph Firman started his own firm Van Diemen with business partner, Ross Ambrose. Based in the grounds of the Snetterton motor racing circuit in Norfolk, he aimed to meet the increasing demand for cheap, reliable and above all, fast production racing cars for the Formula Ford motor racing class. Van Diemen led the class for over twenty years, producing four cars a week and became the largest manufacturer of bespoke racing cars in the world.