Nonsense, where are you getting your information from? Parts count is high, not low: Say 16 blades in the compressor, 24 in the turbine. Each blade in the turbine is very expensive to produce, using high-temperature alloys which are also very hard.
The centrifugal compressor and the turbine are probably precision casted items, one piece, how they are attached and what materials is a different matter and maybe above our pay-grades :-)....
“Nonsense, where are you getting your information from? Parts count is high, not low: Say 16 blades in the compressor, 24 in the turbine. Each blade in the turbine is very expensive to produce, using high-temperature alloys which are also very hard.”
Have you ever seen an exploded view of a 4 cycle engine and automatic transmission?
I stated that there would be a trade off in increased cost of materials versus decreased amount of material needed.