a modified version of the Ford 9-inch differential for the RS500 Sierra. Although the Sierra was a European car, the near bullet proof differential was seen as vital to Sierra runners in Australia due to the standing starts used in Australian racing rather than the rolling starts used overseas. Later in 1988, Ford also released their own official, lighter version of the 9-inch diff, but the DJR unit would prove to be popular due to its lower cost. During 1988 Johnson also managed to homologate the Australian designed and built Hollinger gearbox for the cars which proved more reliable than the German built Getrag gearboxes that were common in most Group A cars at the time. In August 1988 the team air-freighted Johnson's ATCC winning car to England to compete in the RAC Tourist Trophy at Silverstone which was a round of the European Touring Car Championship. Johnson easily qualified on pole, almost half a second ahead clear of the leading Eggenberger Motorsport and Andy Rouse Sierras, and went on to an early race lead. The car was eventually slowed by a lengthy stop to replace a failed water pump and would ultimately finish the race in 21st place, but they had proven that the DJR Sierras were now the fastest in the world after also claiming the touring car lap record with the fastest lap of the race. The speed of the DJR Sierra created interest and at the end of 1988 Robb Gravett of British team Trakstar purchased two DJR Sierras to supply his team with his Sierra RS500s, winning four races to finish the 1989 season 2nd in class and 4th overall (Gravett, thanks to his Shell sponsorship in the British Touring Car Championship through its Gemini Oils brand, had driven for DJR at Bathurst in 1988 and 1989). In 1990, Robb Gravett won the championship with nine race wins. After the two lead cars suffered mechanical troubles, Johnson and Bowe commandeered the John Smith / Alfredo Costanzo car (the oldest and slowest of the three entered being Johnson's 1987 Bathurst and Bowe's 1988 ATCC car) to finish second in the 1988 Bathurst 1000 behind the Sierra of fellow Queenslander Tony Longhurst and his co-driver Tomas Mezera, before winning in 1989 after leading every lap despite a late race loss of turbo power. Johnson claimed his first pole position at Bathurst in 1988, and again sat on