BOV legalities??

[Steve]

Hi guys,

Just thought I would throw in my 2c if that's ok:)

turbo cars are fitted with bovs that plumb back - this is something the manufacturer does, and for good reason (another story)

atmo BOV vent crank case gasses to the atmosphere - this is in direct contradtion of road traffic acts australia wide, and it also contravenes EPA reguations.

It took me a while to work out why atmo BOVs are illegal, until I was reading ADRs with regard to crank case gasses.

All vehicles manufactured after 197? (from memory) must burn crank case gasses through the cylinders as part of emissions control - this is where the problem lies, as under boost crank case gasses go into the intake after the afm and before the turbo (which is why we fit catch cans). Once we take out foot off the accelerator, those gasses vent to atmo.

Hope that clarifies.

As for noise, the only regulations I could find were on vehicle exhaust noise, as for removing a 'turbo whistle' OMFG how can you remove something that doesnt exist - should take him to court purely on the principle - like to see the copper produce a dictionary (or any other legitimate) definition of a 'turbo whistle'. If a defect notice is a legal document, shouldnt the issuing copper be under some sort of requirement to get his terminology right?

Should get a statement off a mechanic to the effect that there is no such thing as a turbo whistle, then go see the guys supervisor and make a complaint that you wasted time trying to remove something that doesnt exist:)

[ARKAD]

BUGGER!..thanks for that tho steve... would have been handy if DOT had told me that...

[MotoX]

CRANK CASE GASSES are different form your bov gasses.

catch cans are used to stop- the amount of shitty blow by in your engine. mostly used for ****ed cars, or crazy high performance cars. bov's vent air that has come from your air filter, thru your turbo then thru the intercooler to your pipes.

there must be different laws in SA. as this is the Queensland section.

now listen. Atmo BOV are legal.so long as they comply to the noise and polution levels.

[Steve]

Where do the crank case gasses go when under boost?

All cars create blow by, whether only a little or alot. If you have a look at the two connectors on top of the rocker cover you will see that they go to the intake, after the AFM, as under boost the gasses cannot go into the plenum for obvious reasons, which is prevented by the PCV (positive crankcase ventilation) valve.

If the gasses did not go into the intake, or were vented to atmosphere, the crankcase could pressurise and cause all sorts of problems (like blowing gaskets and seals - not pretty)

It was only in the early seventies that cars started being required to comply with emissions standards, and the gasses could not longer be allowed to vent to atmosphere.

If the rest of you emissions control is correctly plumbed up, there is no physical way you can stop some crank case gasses getting into the charge air. It is this charge air that vents when the BOV lifts, hence atmo is not street legal.

The requirements for cars to comply with emissions standards are the same in every state.

[Steve]

And BOVs dont have gasses, they only vent charge air, ie air compressed by the turbocharger.

[OBSESSD]

What if it's a dual-port BOV and you have it set to recirculate..? Can they still get you for having the vent-to-atmosphere option there..? Or is having it on recirculate enough for them to NOT fine you..?

[PWND]

As long as everything is plugged back in, you should not get fined. 

 

[GTSBoy]

External port would want to be blocked off, minimum.