sentences:  The team suffered turbo failures repeatedly in both qualifying and races despite efforts by Gordon Murray and BMW engineers to improve the car and engine, and Piquet did not score his first points of the season until his win in Round 7 in Canada.The John Barnard designed McLaren MP4/2 with its Porsche built TAG V6 turbo was dominant, with drivers Niki Lauda (the 1984 World Champion), and Alain Prost (2nd to Lauda by only ½ a point), winning 12 of the season's 16 races between them, and saw to it that Piquet could not retain his championship.He scored another win at the grueling Detroit Grand Prix a week after his Canadian triumph, but Piquet would not win again that year.