Although Brabham experimented with airdams and underbody skirts in the mid-1970s, the team, like the rest of the field, did not immediately understand Lotus's development of a ground effect car in 1977. The Brabham BT46B "Fan car" of 1978, generated enormous downforce with a fan, which sucked air from beneath the car, although its claimed use was for engine cooling. The car raced only once in the Formula One World Championship—Niki Lauda winning the 1978 Swedish Grand Prix—before a loophole in the regulations was closed by the FIA.