Raced in F3 winning the Italian Championship in 1985. Raced in F3000 with no success and was then called up by Osella to race in F1.
Forini started racing karts in 1979 in the Italian championship, he also raced in the Alfasud trophy, finishing 5th in 1980.
For 1981, Forini made the step into European F3 before finding success in the Italian F3 series. Having finished third and fifth with his Dallara-Alfa in 1983 and '84, the Swiss driver switched to a VW-powered car in 1985 and emerged as a worthy champion ahead of Barbazza and Caffi.
A largely moribund F3000 season in 1986 left Forini out of the picture, until a surprise call from Osella brought him briefly into the Grand Prix arena in 1987.
In 1988 he raced in German F3 in a Dallara 388 with a VW engine for the JSK Generalbau team, coming 12th overall.
Returning to Italian F3 in 1989 he failed to score a point. Thus for 1990, he stepped down from driving duties to become production manager for the MC Motorsport team.
He re-emerged in 1993 in the Swiss Rally Championship in a Ford Sierra Cosworth.
Franco then became a regular on the Master Kart and celebrity karting scene.
Forini currently owns Tamoil petrol outlets in the southern Swiss towns of Bellinzona, Rodi-Fiesso and Piotta.