I'm a little confused by your post -
BOV stands for "blow off valve," which is something that is used to relieve pressure between shifts or throttle-lifting. The C230K M111 motor already has a bypass valve that is electronically controlled (the piece attached to the airbox).
I've tried to install a HKS super-sequential BOV on it with no success - it cannot be done correctly. (maybe that was just my experience).
If you're looking to increase boost for the supercharger, a pulley kit would be the way to go.
I'm not sure what you meant by "boost flow" - maybe if you clarify a little we can help?