ddnspider

iTrader: (26)

how are they used?i installed the new 1 without putting in any shims/washers and it seems to work fine,what am i missing?

ddnspider

iTrader: (26)

bump.

stevieturbo

on cars with an airflow meter, you do not want the BOV open at idle etc, as it can **** of the AFM readings, as all the air is no longer passing thru it ( assumes vent to atmos BOV )

So some have adjustment to add more tension, so this scenario doesnt occur.

Some might use shims, others an adjusting screw to add tension.

If yours is working fine, and not leaking under boost....dont worry about it.

JAvenger007

iTrader: (9)

whats a good way of checking if it leaks under boost? or at idle?

stevieturbo

Seal up your entire intake system, and pressurise it manually.


You will also need to apply pressure to the top side of the BOV too during this test, otherwise the BOV will start to leak once spring pressure is overcome.

On mine, this starts to happen at about 5/6psi.

Which perhaps isnt good enough ?? If I had 5psi drop across my IC core/TB, then potentially that BOV could start to leak under boost, if I was feeding the top side from the intake ( correct place )

JAvenger007

iTrader: (9)

so the BOV needs to be capped/plugged or does it need to have pressure fed through the top?

stevieturbo

see above

ddnspider

iTrader: (26)

i thought the whole point of the source at the top of the BOV was to feed it vacuum so between vacuum pulling the valve up and pressure from the tubing it pushing it open

stevieturbo

it does that too...

But if you have say a spring of 10psi in there...once boost rose over 10psi, it would blow the BOV open.

SO boost is applied to the top, so this doesnt happen.

A spring strong enough to stop that happening otherwise, would make it imposible for the vac to pull the BOV open.,

ddnspider

iTrader: (26)

isnt the goal to see when or if the BOV cracks open at a given PSI?so giving pressure to the BOV source would hold it closed,so u could check for other leaks but not for the BOV itself correct?

stevieturbo

you want to check for leaks on both.

But you also dont want to be running the absolute minimum spring pressure in the BOV that keeps it closed under boost. Keep it shut a,little tighter to be 100% sure it is never open under WOT boost conditions, or even some part throttle boost conditions

ddnspider

iTrader: (26)

i may just throw a couple shims in mine just to be safe for when i go to higher boost

JAvenger007

iTrader: (9)

Thats what confused me. So we need to cap one side of the charge piping along with a guage and then pressurize from the other side along with adding pressure to top of the BOV?

ddnspider

iTrader: (26)

ok heres the way i see it.
to test all your intake piping you cap off and connect a pressure source right off the turbo along with pressurizing the BOV so it stays shut.

to test the BOV let the car run and rev it to redline and let out and have someone see if it opens when u let out.or u can pressurize the system and not give the BOV a pressure source and see when it opens

stevieturbo

Which is what I said.

Yes, you can do this under full load on a dyno. Revving it with no load on the engine, would be pointless.

ddnspider

iTrader: (26)

i wasnt arguing with u i was concurring with what u said.i read on another site that revving it in neutral and then watch the rpm when it comes back down to idle and if it fluctuates for a sec u know the bov opened

stevieturbo

sorry...

although that last sentence makes no sense to me

ddnspider

iTrader: (26)

i googled b4 i started this thread.some BOV company said that if u rev the motor up when it comes back down to idle if its not smooth or takes a second to idle regularly then its because the bov opened and vented some air.that didnt make alot of sense to me which is why i started the thread

ddnspider

iTrader: (26)

stevie what did u use to cap off and pressure test stuff