R32 Stock Bov

[cainer33]

Hi all

I just bought an R32 gtst. The BOV is stock and it makes a flutter noise when I change gears.

Today I was taking the plumbing off to get access for the coil packs and noticed that when I took off the stock BOV connection to the intake plenum (<> shaped with 2 bolts holding it together), the gasket was there, but the shonky guys who owned it before me had made a plate from a 'Mother' drink can to close off the pipe, essentially blocking the plumb back.

When I took it for a drive after I removed their dodgy 'fix', when it was under boost and gears were changed it made a really bad hissing noise, something was definately wrong.

Anyone know of the problem and how to fix it. I have put the 'Mother' can mod back in place because the car was undrivable otherwise, was not handling boost at all.

[and3_3]

got an air leak!

Get another bov

[2LV8ETR]

Two things.

First, the can gasket was put there to block the bypass valve intentionally. A lot of the younger generation do this for what they refer to as a dose (the flutter) noise. This is potentially harmful and not a good thing to do.

Secondly, by removing the can and you are using a pod filter and you hear a whoosh noise when you change gears, that's just the bypass valve doing it's job to recirculate the pressurised intake charge to the front of the turbo. This is normal if running a pod. If you use a stock filter box, the noise will be less predominate.

[cainer33]

Two things.

First, the can gasket was put there to block the bypass valve intentionally. A lot of the younger generation do this for what they refer to as a dose (the flutter) noise. This is potentially harmful and not a good thing to do.

Secondly, by removing the can and you are using a pod filter and you hear a whoosh noise when you change gears, that's just the bypass valve doing it's job to recirculate the pressurised intake charge to the front of the turbo. This is normal if running a pod. If you use a stock filter box, the noise will be less predominate.

maybe the gasket has broken down because it wasn't a normal air noise, it was a very loud hiss. the stock BOV is just a very simple unit isn't it ? its just plumbing back into the plenum, theres nothing else I need to be looking at besides a new gasket ?

[2LV8ETR]

maybe the gasket has broken down because it wasn't a normal air noise, it was a very loud hiss. the stock BOV is just a very simple unit isn't it ? its just plumbing back into the plenum, theres nothing else I need to be looking at besides a new gasket ?

Was it a constant hiss under boost, or only during gear change?

The stock bypass valve recirculates from the intake manifold to the inducer in the front of the turbo.

[cainer33]

Was it a constant hiss under boost, or only during gear change?

The stock bypass valve recirculates from the intake manifold to the inducer in the front of the turbo.

only during gear change, i only drove it about 50 metres before i went back and replaced the mother can mod. not so much of a hiss more of a roar, definately not like it was supposed to sounds like, the factory quiet standard

[2LV8ETR]

only during gear change, i only drove it about 50 metres before i went back and replaced the mother can mod. not so much of a hiss more of a roar, definately not like it was supposed to sounds like, the factory quiet standard

If it's only hissing during gear change then it's right.

The ultimate question still hasn't been answered - Do you run a pod filter???????

[cainer33]

If it's only hissing during gear change then it's right.

The ultimate question still hasn't been answered - Do you run a pod filter???????

yeah mate its got a pod filter on it.

[2LV8ETR]

yeah mate its got a pod filter on it.

The hiss noise you are hearing on gear change is the bypass valve recirculating the air from the intake manifold to the front of the turbo. Have a look at the valve and you'll see a black steel tube running to the inducer.

You are hearing the hiss coming through the pod filter. If you had the stock airbox in place it would sound like a mild hiss/squeak.

There's nothing to worry about man, you can put the stock bypass valve back in place without any problem.

[WrenchesInTheGears]

yeah, i have a stock bov on my 32 and a pod filter and the woosh/hiss noise is very loud, even tho its plumb back, everyone who goes in it thinks its got an aftermarket one coz its so loud lol.

how bad is it to block it off for shits n giggle for some flutter?

it would be good if it was adjustable so at like say anything under 4 psi boost it woudlnt open and it would flutter but anything more and it would open, that way u could have flutter without the risk of to much damage to your turbo?

[mosquitocoils]

On my R33 I have a pod with stock BOV... very loud hiss when I'm nearing gear change time! hahahaha but yeah, you can block it off for flutters... or squash the stock one down a bit so it tightens it up a bit, for less hissing, and even some flutter.

Alex - a squashed stock bov would do exactly what you described. I didn't want to risk mine, so I bought one off a fellow SAU-er. Ask at wreckers if they have a spare stock one sitting around, but I doubt it. I couldn't find a stock R33 bov at any wrecker near me.

The other options is obviously an aftermarket BOV, tighten it so that it only dumps once the pressure is up a bit higher.

Edited August 30, 2009 by mosquitocoils