The 1977 Brabham BT45B was an improved mid-season evolution of Brabham’s BT45 Formula One car, designed by Gordon Murray and powered by Alfa Romeo’s distinctive flat-12 engine. The BT45B featured refined aerodynamics, improved cooling, and suspension changes that made the heavy Alfa engine more manageable, producing a car that was far more competitive than its predecessor. Driven primarily by Niki Lauda and John Watson, the BT45B delivered Brabham’s best results of the 1977 season, including several podium finishes and strong qualifying performances.