The Stinger has 2 of them too!Purely for sound purposes. It's the piston seal that is important. Our factory one just uses a rubber diaphragm. That design is not too reliable long term to hold boost efficiently. I have been seriously checking out recirc bov's for the VN. BTW-We have the same design recirc bov as the Kia Stinger TT.
If you like V-8's, I just got rid of an 1983 Trans Am I restored. I almost wish I kept it. Here's a pic: