The Keniss LM73 was a highly successful series of racecars used between 1973 and 1987 in various versions, all designed from the road-going Werewolf Roadster Over the 15 seasons the car was used in the World Sportscar Championship; it scored 32 Class victories, 21 overall victories, and 3 Championships (LM81B 1982 LM81B2 1983 LM87 1987). It also won Le Mans 4 times (LM73B2 1975 LM77 1977 LM77B3 1979 LM87 1987). The car was also infamous for being the car William Clay was killed in during practice at Le Mans in 1974. It was involved in numerous other accidents including at the 1973 24h of Daytona. It was replaced by the LM88 for the 1988 season. The car shown was driven by Pietro Kowalzcyk, who took the car to a 4th place finish at Le Mans that year.
The LM73 series used various Supercharged and Turbocharged 4 or 6 cylinder Boxer engines, as explained below.

LM73-LM73B3 (1973-1976)
4.0L Supercharged Boxer-6
496hp
518lb-ft torque

LM77 (1977)
2.4L Twin-Turbocharged Boxer-4
439hp
476lb-ft torque

LM77B-LM77B3 (1978-1980)
4.4L Supercharged Boxer-6
588hp
635lb-ft torque

LM81-LM81B3 (1981-1983)
2.96L Twin-Turbocharged Boxer-4
509hp

LM84-LM84B2 (1984-1986)
3.8L Twin-Turbocharged Boxer-4
575hp
610lb-ft torque

LM87 (1987)
3.8L Twincharged Boxer-4
703hp
822lb-ft torque

Crashed example