He joined Ferrari in 1948, working under Aurelio Lampredi, followed by employment with Maserati (1953-1957), until the company dropped factory works racing. In 1958 he started his own company, known as Tec-Mec (Studio Tecnica Meccanica).
Tec-Mec, assisted by Giorgio Scarlatti, attempted at the tipo F/415 Formula One car, mostly based on the Maserati 250F, in which Colotti had been deeply involved. Stirling Moss failed in his racing with Cooper-Climax T51, fitted with Colottis, unfortunately rather unreliable, gearboxes. Colottis cooperation with Alf Francis lead to the Colotti-Francis systems. With Wolfgang von Trips he designed the Trips-Colotti-Auto Union (TCA).
The company is now called Colotti Trasmissioni.