Is it bad to un plumb stock bov

[nick2jz]

What title says

It it bad to unplumb the stock blow of valve, like the block the hose with a bung

[zch91]

Yes.

Aside from the fact it is illegal and will cost you a defect notice, it will make your ECU have a heart attack and your car will probably run like shit.

What model lib anyway?

[nick2jz]

my07 gtb

Yeah i thought id ask before doing anything

Thanks heaps

[Boostaddict]

Mate ive done it for around 2months as mine was faulty and needed a new one... But became fond of the flutter!! Its addictive !!

You could block it off, just make sure you block the return hose as well as it will run like a pig

[Manaz]

Mate ive done it for around 2months as mine was faulty and needed a new one... But became fond of the flutter!! Its addictive !!

You could block it off, just make sure you block the return hose as well as it will run like a pig

That flutter is the sound of your turbo being slowly fucked...

[DownUnder]

Can we plz not turn this flutter thing into something with sweeping assumptions? A bit of evidence or polite discussion would be great... In my opinion, turbo is not being fucked. Bovs are there for different reasons.

[Boostaddict]

Can we plz not start this flutter thing... turbo is not being fucked. Bovs are there for different reasons.

I dunno if it does hurt the turbo or not....!! But I loved the noise!

What don't you think it is an issue??

[DownUnder]

I see people arguing about it on forums all the time. I have mates that have run their turbo's like that for ages and never had an issue.(AFAIK) From what I understand it decreases performance though. Possibly something to do with throttle response. Can't quite remember the details of a technical article I read a while back...

[Manaz]

Can we plz not start this flutter thing... turbo is not being fucked. Bovs are there for different reasons.

As I understand it, the flutter is caused by compression waves in the intake colliding with the compressor blades. And it's this "cavitation" that can cause damage by upsetting the bearings over time, or accelerate the death of a turbo that already has issues.

[Robbks]

pressure "waves" and cavitation are two different concepts.
think about it,
pressurise a pipe with an open end (the pump has to spin a lot faster than pressurising a pipe with a closed end)
then suddenly block the pipe. the pump is still spinning fast, so pressure increases and then the pump cavitates (slips or chops the air).
that's your sound, the compressor blades chopping the pressurised air.

[DownUnder]

http://www.gfb.com.au/tech/tech-article ... ssor-surge
There's what I was looking for. A company that sells BOV's saying the lack of one won't cause massive turbo damage (they did say some was possible though)

While it's very possible I've heard that on a subaru sometimes removing the recirc upsets some sensors and if it's not tuned for it you can have crappy performance. Also I really hope this stays as a discussion as it is so far. There's some terrible threads on NAISOC. It's one of those things where there is no hard evidence either way, and everyone is going to have their own opinion. Like regular oil vs synthetic oil...

[GT-B Spec R Pilot]

What title says

It it bad to unplumb the stock blow of valve, like the block the hose with a bung

Do you have a particular reason why you want to do this? What are you trying to achieve?
Everything you do is a trade off I some way so it really depends what it is you are trying to achieve..

[Robbks]

http://www.gfb.com.au/tech/tech-articles/11-the-truth-about-compressor-surge
There's what I was looking for. A company that sells BOV's saying the lack of one won't cause massive turbo damage (they did say some was possible though)

While it's very possible I've heard that on a subaru sometimes removing the recirc upsets some sensors and if it's not tuned for it you can have crappy performance.

On the earlier models with the shorter intake pipe they would suffer from "Reversion" or "PFC disease" with big aftermarket BOV's which plumbed back or no BOV.
there would be such a huge rush of air back into the pre-turbo intake pipe that the air would flow backwards through the AFM causing erroneous readings.
Fitting a CAI and pod and relocating teh AFM closer to the inner guard or within the inner guard would help stop this issue, or fitting a FMIC and CAI would help too.

There were also many reports of the VF22 Turbo which had funky ceramic blades (Correct me if i'm wrong) were prone to failing with the little excess pressure caused from running with no BOV.

But back to the original question,
the stock BOV's sit a little bit open at idle, which would let in un-metered air if not plumbed back

[MumblesOfficial]

Cut up a beer can and slot it under the bov. Takes about 2min. You'll need a 10mm socket. Alternatively, get a piece of aluminium plate and drill a hole in it like I did still vents a bit of pressure but still flutters on boost