 With new regulations for Group C Touring car racing introduced by the Confederation of Australian Motor Sport in 1980 which forced teams to use low emission engines, the HDT (by now owned by Brock and with actual support from Holden dealers after Holden had pulled out of racing at the end of 1979) had been secretly testing a VB Commodore as its replacement for the A9X Torana.The new regulations saw that the Holden's racing 5.0-litre V8 engine had a drop in power from 1979's to approximately .However, the new regulations also saw to it that the HDT had arguably the only race ready car for the 1980 Australian Touring Car Championship.