Brian Hart
After 1984 companies like Renault, Honda, BMW, TAG-Porsche, and Ferrari were able to develop their engines to receive much higher turbo boost than the Hart 415T. This resulted in Brian Hart stopping development of the engine. The last time it was used was by the Haas Lola team at the 1986 San Marino Grand Prix, with Patrick Tambay qualifying 11th but retiring with engine troubles after just five laps.