Question about BoV on RB25DET NEO

[Kapr]

Hi. Iam just curisou about this topic.
I saw this video.
It is about Greddy Type FV2.
I know that BoVs are about that sound but how and when to use it?
I read some topic here and from what i have understand on stock RB with MAF there will be some "problems" if you use this BoV?
It vents the air in to the atmosphere and the MAF on stock car needs this air back in to the intake and not out? Or is it wrong?
If so...i saw you can put some adaptor to circule air back...but does that not "loose" that sound?

I saw another BoV from Turbosmart and it has two "exhaust" like ports? One is for the stock tubing for letting air back and one is for "sound" and let the air in the atmosphere?

Can someone please explain?
This is the Greddy one: 

And this is the Turbosmart.

 

 

THANK YOU!!

EDIT:
So i read about this topic some more and i if i understand that correctly:
That Greddy can function either like BoV or 100% Bypass valve?

And that Turbosmart is what they called hybrid so you can adjust what and how many air can be vented out or back in?

Is this right?

THX!

Edited Saturday at 01:03 PM by Kapr

[Murray_Calavera]

You've just discovered a really good reason to tell yourself, yes, I do need to buy an aftermarket ECU.

Put the MAF in the bin. Slap in the new ECU and have a think about what turbo sounds you prefer. 

Do you want a 90's style BOV wooosh?

Do you want a hektik tsututututu? 

Mate, can't go wrong. Just gotta get that ECU and the world is your oyster. 

[Dose Pipe Sutututu]

Want that BOV to work properly? Pair of with a Haltech and a bunch of sensors.

Modernisation, better fuel economy too.

[Kapr]

Ok thanks guys that is what i thought and learned from all the comments/videos too.

If i want to BoV i need/want to have standalone ECU 🙂

And the bypass valve tge car has is good for stock(little bit more) power.

[GTSBoy]

Stock bypass valves are good for plenty of boost.

[Kapr]

Yeah i know(now)
I just wanted to ask.
It maybe looks like i get my hands on RB25DET NEO for swap 🙂