BOV Question - Is it Plumback or Atmo? (Pics included)

[Wink]

Just got my R33 and I have a GReddy BOV fitted but I don't know if it's plumback or atmo venting.

What's the small pipe which leads to the air?

What's the pipe which leads into the engine block?

What's the big pipe leading to the BOV?

[BHDave]

Looks plumb back to me. the big pipe will return to the inlet infront of the turbo.

The small pipe runs to the manifold and gives the boost/vacuum signal and the other one that isn't connected possibly allows the bov to be used as a pop off valve by connecting the signal line there

[Wink]

The BOV is set to soft - does that mean it'll be louder (as in vent more air)? Or is it the other way round? Hard means tightening the nut more.

[R31 POWER]

Thats a Greddy type s,I had one on my car.It is plumback.Here is a install with the guy saying with the small nipple connected

"The smaller nipple on the cast aluminum body of the BOV may be spliced into the turbo outlet pipe or into the line between the turbo and wastgate actuator. Use the T-connector supplied. This connects to pressure even when the other line has vacuum. This will activate the BOV faster by applying pressure under the valve seat.

The smaller nipple may also be left unconnected. The BOV will operate slower and more quietly. I did not test this mode."

http://herpetology.com/dsm/bov.html