Ramirez came from the same Mexican town as the Rodriguez brothers - Ricardo and his brother Pedro - and although he had similar racing ambitions he did not have the money to achieve what they were able to. He studied mechanical engineering at Mexico City University but dropped out to accompany his pal Ricardo Rodriguez to Europe in 1961, when the Mexican went to rent a factory Ferrari for the Italian GP at Monza in which he sensationally qualified on the front row of the grid. The race itself was a tragic affair with team leader Wolfgang von Trips crashing to his death on the first lap - in an accident that claimed the lives of several spectators. Rodriguez briefly ran in second place before retiring with mechanical failure.The pair returned in 1962 with Rodriguez showing his pace, finishing second at Pau and fourth in the Belgian GP. In practice for the Mexican GP in November he rented Rob Walker's Lotus 24 and crashed to his death. Ramirez decided to go back to Europe and went on to work for both Maserati and Lamborghini.In 1966 he moved to England to work with Ford and later joined Dan Gurney's Eagle F1 team. After the F1 team closed down Jo spent three years with Gurney in the United States, working in CanAm, Indycars and TransAm racing but in 1971 he returned to Britain to work as chief mechanic for the John Wyer Automotive Gulf Porsche sportscar team.In 1972 he was back in F1 working with Jackie Stewart and Francois Cevert at Tyrrell and he stayed with the Ockham team until 1975 when he was hired to be the team manager of South America's own F1 team - Copersucar-Fittipaldi. There followed stints as the team manager of Shadow, ATS and Theodore before he joined McLaren as team coordinator in December 1983. From 1984 to 2001, Ramírez was coordinator of this Formula One team, including during the infamous Prost–Senna rivalry of the late-1980s. Ramirez retired in the end of 2001.