Copersucar, as the main sponsor, matched the salary Emerson had been earning at McLaren, betting on the reputation and experience of the two-time world champion. To follow this shift, Ricardo Divila, with the support of Maurice Phillippe, designed the FD04 — a completely new, lighter, and more conventional model, featuring side radiators and outboard suspension. However, excessive chassis flex compromised its competitiveness. Despite this, Emerson managed to score points at Watkins Glen, Monaco, and Brands Hatch.
The pressure to improve led to the hiring of engineer David Baldwin, who began developing a new model for 1977. At the start of the year, the FD04 was raced with new livery designed by Sid Mosca — famed for creating helmet designs for Senna, Schumacher, among others — incorporating yellow as a stronger symbol of Brazilian identity. Emerson started the season promisingly, securing an excellent fourth place at the Argentine Grand Prix, a result he repeated at Interlagos, where Ingo Hoffmann finished seventh in what would be his final Formula 1 race. From then on, Copersucar entered a single car.
The FD04 remained competitive, with a fifth-place finish at the USA Grand Prix, but began losing competitiveness towards the latter part of the season. In South Africa, the Copersucar could manage no better than tenth place, but at the United States Grand Prix, Fittipaldi once again proved his skill and consistency with another fifth-place finish. However, the FD04’s farewell was less impressive, with a 14th place in Spain and a retirement in Monaco, due to engine failure.