The BT49 was created by South African designer Gordon Murray for the Brabham team during the 1979 season of the Formula One motor racing World Championship.

It is built from sheet aluminium alloy with reinforcement from carbon fibre composite panels and is one of the first Formula One chassis to incorporate this material structurally.

This provides more grip and thus higher cornering speeds, but compared to conventional wings creates less of the drag that slows the car in a straight line.

[3] In 1980, a revised version of the DFV was introduced in which ancillaries such as the water and oil pumps were reduced in size and grouped further forwards on the flanks of the engine to provide more clearance for ground effect tunnels under the cars.

The Ford Cosworth engine integrated into the car much more easily than Alfa Romeo's large, heavy and inconsistently sized units: Murray described returning to the DFV as being "like having a holiday".

Throughout 1980 the BT49 was regularly one of the quickest naturally aspirated cars timed on the speed-traps (meaning only the turbocharged Renaults were usually faster in a straight-line), a combination of the low drag aerodynamically slippery bodywork and the development Cosworth engine.

The BT49 was initially fitted with the same gearbox the team had been using since 1977: a six-speed unit designed by Brabham using internal components from Hewland and a casing cast by Alfa Romeo.

The new unit could be fitted with five or six gears and was tall and narrow, allowing a clearer airflow from under the car to the rear, with the intent of improving the ground effect.

[19] The Weismann unit proved difficult to make reliable and was used alongside the original gearbox, mainly on a spare chassis, until the Dutch Grand Prix, after which it was put to one side.

[23] That year a minimum ride height of 60 millimetres (2.4 in) was introduced and sliding skirts were banned, with the intention of limiting ground effect and slowing the cars.

[24] More significantly, Murray devised a hydropneumatic suspension system for the BT49C in which soft air springs supported the car at the regulation height for checks while stationary.

[23] A lightweight qualifying chassis was produced, featuring a small fuel tank and lighter reinforced carbon-carbon brake discs and pads.

The car soon showed promise: Piquet ran third in the race on the high speed Circuit Île Notre-Dame before retiring with a broken gearbox.

At the season finale in wet conditions at the Watkins Glen International circuit, Zunino spun off although Piquet set the fastest lap before a driveshaft failed, putting his car out of the race.

[28] Early in the 1980 season, Piquet's car scored points finishes at the Argentine and South African Grands Prix, behind Alan Jones' Williams FW07-DFV and the turbocharged Renault RE20 of René Arnoux.

Towards the end of the season, the suspension was reworked for the Dutch Grand Prix on the high speed Circuit Park Zandvoort, lengthening the wheelbase by three inches and allowing the car to run in a lower drag configuration.

[29] The BT49s driven by the team's second drivers—Zunino and then from mid-season Mexican Héctor Rebaque—either retired or finished outside the points, with the exception of Rebaque's sixth place at the Canadian race.

To the team's surprise, it was the only car to exploit the "obvious" loophole in the new ground clearance regulation by lowering itself, but the BT49Cs raced with conventional suspension after the hydropneumatic system repeatedly jammed.

[30] The cars ran on Goodyear tyres again from the sixth round of the championship; motorsport author Doug Nye believes this cost the BT49s good results at several races while the American company adapted to the latest Formula One developments.

[8] Piquet finished fifth at the final race of the season—the Caesars Palace Grand Prix—to take the title from Carlos Reutemann in a Williams FW07 by one point.

The BMW-powered BT50 made its debut at the start of the 1982 season, taking advantage of the high-altitude Kyalami circuit in South Africa, which favoured turbocharged cars.

Piquet finished first at the Brazilian Grand Prix in a BT49D, but was disqualified after a protest from Renault and Ferrari on the grounds that the car had raced underweight due to its water-cooled brakes.

FISA ruled that in future all cars must be weighed before coolants were topped up, resulting in a boycott of the fourth race of the season by most of the DFV-powered teams, including Brabham.

[32] Under threat from BMW, Brabham did not use its Ford-powered BT49s again until the sixth race of the season, the Monaco Grand Prix, where one was entered for Riccardo Patrese alongside Piquet in a BT50.