Originally Posted by EVOHUNTER

its beneficial for a NA car and a boosted car.

During normal operation of an internal combustion engine, there’s a compressed air and fuel mixture inside the combustion chamber that is ignited and as a result, forces the piston down. A small amount of that ignited mixture leaks past the piston rings and ends up in the crankcase. This leakage is often referred to as “blow-by” (leakage past the piston rings), as well as oil mist.
Some of the oil mist and other products settle along the engine intake and over time form a “gunk.” The oil catch can collects the oil mist and condenses the fuel vapors while allowing “cleaner” gases to be passed back into the intake.