Tasman Cup Formula 5000 1970-1975
The 2½-litre 'Tasman Formula' had worked well for the Australian and New Zealand Internationals since 1964, but by the end of the decade the Coventry Climax FPF was very aged technology, and although the Repco engine was available in a 2.5-litre capacity, newer technology such as the Cosworth DFW was out of the financial reach of most of the local teams.
When Formula 5000 first appeared in the US in 1968 as Formula A, the Kiwis were immediately interested and ran a race at Bay Park with US visitors in December 1968. The New Zealand Gold Star was opened to F5000s for the 1969/70 season, and at about the same time Frank Matich bought the first F5000 car in Australia. In Australia there was a vociferous debate about whether to move to 2000cc racing engines, as used in sports car racing and adopted for single-seaters in Japan, or to move to F5000. Eventually, CAMS decide to stay on the fence and allow both.
For the 1970 Tasman Cup, F5000 would be allowed on both sides of the Tasman Sea, and 2.5-litre racing engines would still be allowed, but the 1970 Australian Gold Star would be for 2.5-litre engines until a move to F5000, plus a class for 2000cc racing engines, in 1971. It was a bit of a muddle. By 1972, it had finally settled down and only 5000cc cars competed.
Non-championship races in brackets.