Brabham BT49

The Brabham BT49 was a ground effect Formula One car designed by Gordon Murray for the Brabham team. It was used over four seasons, taking a total of seven wins, six poles and 135 points. Nelson Piquet used this model to win the 1981 Formula One drivers' championship.

Concept

The BT49 was designed on short notice when Bernie Ecclestone decided to end Brabham's relationship with Alfa Romeo after the Italian constructor started testing its own Formula One car in the summer of the 1979 Formula One season.Fact|date=May 2008 The Alfa Romeo engines had been powerful, but heavy, unreliable and very awkward to work with. Murray described returning to the Cosworth DFV for the BT49 as being "like having a holiday."

The car was an extremely simple and uncomplicated design, based around the Cosworth DFV. It was an aluminium alloy monocoque tub into which a carbon fibre composite insert was fitted, forming the driver's seat, fuel tank and top of the chassis. The first two chassis were built up from cut-down chassis of the Alfa-Romeo V12 powered BT48. The BT49 featured extremely low sloping sidepods housing the radiators, which were laid at a shallow angle, and advanced ground effect tunnels built into the underside of the car. The car featured the carbon-carbon brakes which Brabham had been developing since 1976.

After their experience with the BT48, Brabham's first proper ground effect car, the BT49 had well-developed aerodynamics. In its first years of use these were enhanced by sliding skirts sealing the underside of the vehicle. For the 1981 season, however, the FIA banned the sliding skirts and introduced a 6 cm minimum ground clearance intended to slow the cars in corners by limiting the downforce created by aerodynamic "ground effect". Brabham were the first team to find a way around this rule.

Ground effect reduces the air pressure under the car, sucking it onto the track with the effect increasing as the underside of the car gets closer to the track surface. [Haney, Paul and Braun, Jeff [http://www.amazon.co.uk/exec/obidos/ASIN/0964641402 Inside Racing Technology] pp. 15 - 19 TV Motorsports ISBN 0-9646414-0-2] Gordon Murray devised a hydropneumatic suspension system for the BT49C in which compressed air acted as the spring. The air "springs" supported the car at the regulation height for checks while stationary in parc fermé. At speed, where the ride height could not be measured, downforce compressed the suspension and the car settled to a much lower ride height, creating more downforce.

Brabham were accused of cheating by other teams. Murray believes that the system was legal, as any suspension system will compress under download. The loophole was in the degree of compression permitted, which was not specified under the rules. Murray also feels that the team's effort in developing the system was wasted when, part-way through the season, FISA decided to permit systems with a simple switch for lowering the ride height. [Henry (1985) pp.223-225] Although this required the sidepods to be redesigned and the drivers were exposed to massive lateral g-forces, the system worked perfectly.

During the 1981 season, Brabham signed a deal with BMW to supply turbo engines for 1982. A BT49 was used as a testbed for the new engine, and Piquet was ecstatic about the massive power of the unit. In qualifying trim the BMW turbo produced up to 1500 horsepower.

Murray was reluctant to build an entirely composite chassis until he completely understood how the new materials worked in a crash, an understanding achieved in part through an instrumented crash test of a BT49 chassis, with its carbon fibre components.

Racing History

Nelson Piquet debuted the car at the 1979 Canadian Grand Prix, in the red and blue colours used that season. Niki Lauda drove the car in practice, but abruptly quit the sport before the race. The BT49 was then developed for the 1980 season, allowing Piquet to challenge Alan Jones and Williams hard for the world championship. Piquet took three wins but lost out in Canada, first when Jones put Piquet into the wall at the start and then when the engine failed in the spare car during the race.

In 1981 Piquet used the modified BT49 to take another three wins and snatched the world championship away from Williams driver Carlos Reutemann in the final race, though Williams again won the constructors' title.

Brabham used the BT49 occasionally during 1982 while developing the BMW-powered BT50, itself closely based on the BT49. Riccardo Patrese took the car's final win at the Monaco Grand Prix that year.

The BT49 took a total of seven wins, six poles and 135 points in its career.

BT49s are still raced today in historic racing championships.

Notes

See also

* Williams FW07
* Lotus 88

External links