Hello, I did a detailed section about the BRABHAM BT49, world champion in 1981 with Nelson PIQUET (
http://www.gurneyflap.com/ ). It is, in my opinion, one of the most beautiful Formula 1, and with its pure ground effect (with the sliding skirts) maybe the most efficient car ever. It produced more than 2000 Kg of downforce without any front wing and a with a very little rear wing.