I hate asking, but...

[Guest MFX_R33]

Well there you go. I still cannot fully explain why this happens. I believe it has to do with the fact that the pipework is so long that when the throttle is closed suddenly the air pressure surges from end to end, similar to water in a narrow trough. In short pipe work if this does happen it is much less dramatic and not enough to effect the BOV.

Jeff.

[TTT]

MFX-R33... I am very interested to see this..

If you are serious about showing me, I'd like to take you up on that offer..

As far as I know it's not possible, but I am willing to think outside the square and be shown something that I think is not possible..

I am not being sarcastic, I am genuinely interested in seing this..

[poyz]

Wow, what a complete turn around, just the other day I was deaf and unbelievable

[Guest MFX_R33]

Check your PM.

[DCIEVE]

are there reciprocating bov's??

this would also make a flutter as the air is released. ie a little air is released each time the piston or whatever spins, and it spins bloody fast making that ch ch ch noise

[Roy]

I dont have all the answers and i have studied fluid mechanics. Even so i cant explain the cause of the noise, i have thoughts but my old PBR BOV on my R31 souded completely different to the one i heard on a 13B.

At the end of the day i KNOW cars running BOVs have can make this noise. Looks like ill have to break out the TIG set and start experimenting with ocations, perhaps closer to the IC outlet.

Most 80 touring cars did run BOVS, to my knowledge only the DR30 and R31 Nissans made do without. Have you ever seen the engine bay of the Caltex Sierra, it did run a BOV.

[Guest MFX_R33]

DCIEVE,

are there reciprocating bov's??

If there are I have not seen them. Almost all BOV's i have seen are a different version of the same basic piston style. The only exception I can think of is the HKS Super SQV, which has a more complicated design (and they are prone to siezeing), but still not reciprocating.

Jeff.