Stig Blomqvist beat the defending world champion and Audi teammate Hannu Mikkola to the drivers' title.
Michèle Mouton had a part-time contract and two-time champion Walter Röhrl was added from Martini Racing.
Lancia Martini kept Markku Alén as their primary driver for the season and also featured Miki Biasion and Attilio Bettega.
Lancia boss Cesare Fiorio had also signed Henri Toivonen from Porsche, stating that "Audi will have four top drivers next year so it would be very difficult competing with only two.
His performance showed that Peugeot Sport, headed by Jean Todt, had a winner that could beat the Audi, which they would do in the coming years of Group B dominance.