in called All American Grand Touring (AAGT) to give equal latitude to foreign cars. Turbocharged cars were permitted in . In the same year, Bishop invited a pair of Jean Rondeau-built Inaltera's to compete as "special prototypes". They became the foundation of the newly formed Grand Touring Prototype (GTP) category in , with separate rules similar to Group C (Bishop was unhappy with the fuel consumption formula of the latter). In , Fédération Internationale du Sport Automobile (FISA), the organizers of the World Endurance Championship (WEC), attempted to unite the two organizations by scrapping the existing formula and adopting IMSA rules. This did not please Porsche, which was spending vast sums of money on engine development at the time. Porsche responded by boycotting the 24 Hours of Le Mans of that year. FISA responded by abandoning the rule change for the time being. In , FISA president Jean-Marie Balestre almost made a successful attempt to settle the dispute by announcing that turbochargers and fuel restrictions would be phased out by 1989 (excepting naturally aspirated engines below 3.5 liters). This attempt failed, as did another in 1991, in which with chassis ballast penalties for turbocharged cars rendered them uncompetitive, except at Le Mans. IMSA continued to have success with its own Camel GT series. New ownership In 1987, John Bishop had to undergo a heart bypass surgery, forcing him to rethink his priorities. He began to realise that the Camel GT series was in danger of becoming oriented toward the factory-backed teams and less to the privateers as Bishop originally intended. Rules were modified to accommodate the factory teams, which wanted to get into the series, despite Bishop's belief that such changes would be unfavorable to the series in the long run, especially if they failed to meet their objectives. In January 1989, the Bishops sold the company to Mike Cone and Jeff Parker, owners of the IMSA Grand Prix of St. Petersburg. Bishop shortly stepped down as the organisation's president in favor of Mark Raffauf, his deputy president and the organisation's representative on the ACCUS (Automobile Competition Committee for the United States), an FIA recognised sporting body. Cone and Parker in turn sold the organization to businessman Charles Slater by the early 1990s. In 1996 Slater sold the organization with previously accumulated debt to Roberto Muller (ex-CEO of Reebok) and Wall Street based portfolio manager for Bill Gates, Andy Evans,