The PA9 was the logical further development of the PA8, with all PA sports car types based on the body shape of the PA3 and having a more or less similarly designed monocoque.
The Osella works drivers Giorgio Francia and Lella Lombardi, who had been active in the Formula 1 World Championship in the 1970s, won the Mugello 6-hour race well ahead of the privately registered Porsche 935K3 of John Cooper and Dudley Wood as well the BMW 320i by Anton Fischhaber and Mario Ketterer.
Lella Lombardi/Giorgio Francia and Carlo Franchi and Luigi Moreschi only had to admit defeat to the Porsche 935K3 of Edgar Dören , Jürgen Lässig and Gerhard Holup.
The two Osella works teams also finished second and third overall in the Pergusa 6-hour race; this time behind the Lola T600 by Emilio de Villota and Guy Edwards.
At the 1000 km race in Monza, the factory PA9, driven by Diulio Truffo and Luigi Moreschi, failed after 158 laps due to gearbox damage.
In addition to chassis 113, which the Italian Jolly Club team unsuccessfully used in the World Sportscar Championship, a converted PA9 (originally a PA8 ) made its way to North America and was used there by Jacques Villeneuve senior in the Canadian-American Challenge Cup, better known as Can-Am series, driven.
Mauro Nesti won the title of European Hill Climb Champion in the racing car class six times in a row with his PA9 from 1983 to 1988.