The Porsche 934 was a racing version of the Porsche 911 Turbo, prepared to FIA Group 4 rules, similar to the Porsche 935 which was prepared to FIA Group 5
The 934 was introduced for the 1976 racing season. It was manufactured for two years, 1976 and 1977, with at least 400 being manufactured. Toine Hezemans drove this car to victory at the European GT Championship, while in the U.S., with George Follmer at the wheel, it also became the Trans-Am champion. It continued to win races throughout the late 1970s.
Alan Hamilton the Australian Porsche distributor at the time owned one of these cars and competed and won the 1977 Australian Sports Car Championship and in 1980 the same car won the title with Allan Moffat behind the wheel
Source: Wikipedia (original)