[TonyG]

The throttle bodies, in the case of the TWM 3003, have 1 vacuum port per bank. Each 1 vacuum port is connected to 3 cylinders.

You would then "T" them together and run them to a CBV. Most aftermarket CBV's are adjustable, meaning that you can adjust the point at which they open.

A bypass valve is the same as a blow-off valve, with the exception that one does not vent to atmosphere. Instead, it simply "blows off" to the turbo inlet pipe.


And when it is open, under all light load conditions, air is drawn in the opposite direction, into the engine through the CBV (around the compressor, intercooler, and associated plumbing).

In short, the blow-off as well as the bypass operation in an ITB engine is performed exactly the same as a common plenum/single throttle body situation. No difference.

TonyG