Brabham cars were also widely used by other teams, and not just in Formula One. Jack Brabham and Ron Tauranac called the company they set up in 1961 to design and build formula racing cars to customer teams Motor Racing Developments (MRD), and this company had a large portfolio of other activities. Initially, Brabham and Tauranac each held 50 percent of the shares. Tauranac was responsible for design and running the business, while Brabham was the test driver and arranged corporate deals like the Repco engine supply and the use of the MIRA wind tunnel. He also contributed ideas to the design process and often machined parts and helped build the cars.