Forini was born in the Italian part of Switzerland, close to the northern tip of Lake Maggiore. As racing was banned in Switzerland he was drawn to the Italian racing scene. He won his first Formula 3 race in 1983 with a Dallara chassis and he spent the next two seasons developing the Dallara into a dominant chassis with the Venturini team. In 1985, however, he switched to Forti Corse and beat Alex Caffi and Fabrizio Barbazza to the Italian title. He moved up to Formula 3000 in 1986 with Enzo Coloni's team but later switched to San Remo Racing. His best result was a sixth place. In 1987 he found sponsorship to run a second Osella in a handful of races and qualified for the Italian and Portuguese GPs.