It's more BS just like the "TURDULATOR".( oops misspelled and decided not to correct.) Turbulence in the intake system causes restriction. Any swirl effect it could impart would be have negligable effect once the airflow is forced into the intake port at the valve.( other than to be a restriction to flow ) The best flow before the port is always laminar flow.( If you doubt that statement, go look up laminar flow and boundry layer discussions.) That is not opinion, I've flowed manifold and intake ports for over twenty years and I've never found any effect on swirl and tumble in the chamber except motion that is induced right at the port. ie; shrouded valve guides and even moderate swirl inducers such as ridges in the intake port only restrict flow and do not have impact on swirl and tumble. Here's the other part of the "myth" none of these "ads" mentioned. The BS about better atomization of the fuel. Injector flow streams are very sensitive to induction airflow. There is a tremendous amount of work involved in injector targeting and injector timing to insure the proper fuel atomization and spray pattern as the fuel enters the combustion chamber. Mixture motion in advance of the injector spary cone will cause the injected fuel to contact the port walls. (especially, if it wasn't there when the manifold was designed and developed )Fuel on the walls is something design engineers try to avoid, as when fuel that contacts the port walls is injested into the chamber, the droplet size is invarably larger than those injected straight from the injector tip. New injectors are designed to deliver smaller and smaller droplet size to do exactly what these "ads" claim, the best atomization of the fuel. AND THAT IS NOT accomplished by casuing the injector stream to contact the port wall.
besides, i have no life and nothing else to do
