No bovs can't make that sound..
it doesn't matter where it is placed..
that fluttering sound CAN NOT come out of the opening of a bov.
The bov can only make one sound... a single release of air in one hit.. it can't open and close to make different fluttering sounds.
If you have your bov mid way along your pipes, and you are hearing a fluttering sound, it is not coming out of the bov.. it just means that there isn't enough pressure to open the bov.
If you want a fluttering sound, remove your bov and block off the holes... if you want a bov noise, fit one and adjust it so that the piston is JUST closed at idle and it will psshht every gear change..
It's not that hard.
There is no other way to get a fluttering sound from your TURBO car.