 Complete the following phrase:  Piquet formed a close and long-lasting relationship with Ecclestone and the team, losing the title after a narrow battle with Alan Jones in 1980 and eventually winning in 1981 and 1983. In the summer of 1981 Brabham had tested a car powered by a BMW turbo engine, and 1982s new BT50 was powered by BMWs turbocharged four-cylinder M10. Brabham continued to run the Ford-powered BT49D in the early part of the season while reliability and driveability issues were sorted out by BMW and its technical partner Bosch. Ecclestone and BMW came close to splitting before the turbo car duly took its first win at the 