Brian Hart
As part of Toleman's entry into the FIA Formula One World Championship in 1981, Hart developed a turbocharged version of the 420R. Although it was initially underpowered and unreliable, it was enough to establish "Brian Hart Limited" as a Formula One engine supplier. Hart continued as Toleman's engine partner until the team's purchase by Benetton and later supplied engines to RAM, Haas Lola and Tyrrell in the 1980s, as well as Jordan and Arrows in the 1990s.