The BMW M106 engine was employed in the turbocharged BMW 745i Turbo beginning in 1983. The M106 replaced the M102 engine in the 7-series and was the highest performing BMW engine at the time.
M106 Engine Specs
The M106 was a six cylinder engine displacing 3.5 litres and was turbocharged to approximately 10 PSI. Compression ratio was 8.0:1, good for power ratings of 252hp at 5,200rpm and 127kg-ft. of torque at a low 2,200rpm. Bore and stroke were 92mm and 86mm, respectively.
About the 745i Turbo
The 745i Turbo was the only car that employed the M106 engine. Chassis code conforming to BMW nomenclature was E23. The Turbo was a European-only model and was very rare at its time. Around 1,000 745i cars with M106 engines were imported to the United States through grey-market channels with questionable legality, making the car one of the hardest BMW cars to obtain to this day.
M106 Engine Successors
After 1985 the 745i Turbo went away from the European market. The engine which succeeded it was the naturally aspirated M30B5 engine, which produced similar power but was not available with a turbocharger. BMW did not produce another turbocharged engine until 2007 with the introduction of the twin-turbo 3.5 litre used in the 135i, 335i and 535i