Can you loose boost from a B O V

[rx7ben]

As above can you loose boost from a dumpvalve. Ive had a loss of boost for a while now but had it down to somthing in the rats nest. Then yesterday i fitted a used Bailey dumpvalve and i think im dropping boost again. Not only that this bov goes off really easy even when im driveing normally and i can here it hissing when im on the gas lightly. Could it be this, i thought the bov should only go off when you let off boost.
 
Thanks

[chrisJDM]

yes im sure you can, if its not holding the boost properly, ages ago when i first got my car i got a cheapy GReddy BOV which didnt hold boost properly then i got a new bailey venturi one and that worked fine

[rx7ben]

Hmmm maybe this is the problem then. I had a Blitz one that i took off and replaced with the bailey one but thay both are secondhand. So maybe this is the issue

[chrisJDM]

are you still on twins??? there are LOTS of things that can cause boost issues on twins, mainly rats nest piping and solenoids also intercooler piping can cause issues.  I wouldnt have thought if you have tried two different BOV\'s and still getting same results that its the BOV\'s that are the issue more likely to be something else.

[rx7ben]

are you still on twins??? there are LOTS of things that can cause boost issues on twins, mainly rats nest piping and solenoids also intercooler piping can cause issues. I wouldnt have thought if you have tried two different BOV\'s and still getting same results that its the BOV\'s that are the issue more likely to be something else.

 
Yep still on twins, your probaley right cant be two dodgy bov. Can you adjust bov spring stiffness. It seems like this one is going off to easy even when im not on boost, this is wrong isnt it. Allso its whistling a little bit even when im applying the gas.
 
As you can tel im a complete novice at this stuff so thanks for you help:D

[chrisJDM]

some you can adjust and some you cant the GReddy one i had you could but not the baileys one.  That def does not sound right going off so quick, do u hav any mates with FD\'s you could borrow a BOV from that you know is working, or even get the standard valve and plum that back in just ot test if this is the problem or not.  Or there may be someone on here who lives near you who could lend you one, im sure there are a few members from the reading area.

[rx7ben]

some you can adjust and some you cant the GReddy one i had you could but not the baileys one. That def does not sound right going off so quick, do u hav any mates with FD\'s you could borrow a BOV from that you know is working, or even get the standard valve and plum that back in just ot test if this is the problem or not. Or there may be someone on here who lives near you who could lend you one, im sure there are a few members from the reading area.

I dont no anyone  near me with a fd :3Confused I could borrow my brothers one off his scobby. If the dumpvalve is going off so easy do you think its leaking ?

[chrisJDM]

im not a expert but from what you said sounds like it, i really think you need to test it with a BOV that works then u will know for sure

[Nik da Greek]

Just disconnect the actuator line from the dump valve to the plenum (or wherever you\'ve taken the vacc source from) so the dump valve won\'t open at all. Won\'t do your turbos any harm at all to run without a dump valve for a bit, certainly not for the short while it\'d take to see whether  removing the DV from the loop completely has cured your boost leak

[chrisJDM]

thats a very good point nik i didnt think of that, i even run without one on mine

[Nik da Greek]

Hee hee! Doh!

They make a better noise without, tbh. I spent about a month thinking my turbos were making really cool noises, the "chatter" sorta noise, before I realised it was because the DV actuator line was split and it was rarely holding vaccuum long enough to open :Hammer

[SmbFD3S]

i have a baileys on mine mate and it does exactly as you say, but when on WOT it holds boost fine.  Not sure if it\'s correct but i thought it was odd that it vented so easily when light throttle, so i tried the factory BOV and it does the same thing...

[nuki]

i was having loads of boost issues... renewed rats nest... change check valves and solenoids.. changed lots of things and it ended up been the boost gauge.... best thing to do i find is just eliminate things you dont need to use and work your way to the problem.

[Prof]

which version of the baileys BOV do you have ? - there are two versions, DV24 and DV26  - one is a double piston and is designed to block at lower boost - it looks open if you look at the vents, but there is a second diaphragm that holds shut - only a quick plip on the throttle will show it opening if your testing it on the drive.  You can prove it\'s not open by spraying some car cleaner or propane near the BOV - if it leaks then the engine revs will pick up.

[SmbFD3S]

which version of the baileys BOV do you have ? - there are two versions, DV24 and DV26 - one is a double piston and is designed to block at lower boost - it looks open if you look at the vents, but there is a second diaphragm that holds shut - only a quick plip on the throttle will show it opening if your testing it on the drive. You can prove it\'s not open by spraying some car cleaner or propane near the BOV - if it leaks then the engine revs will pick up.

 
Interesting, how would the carb cleaner or propane enter the system? My BOV vents (positive pressure) even at idle and always has done even with the stock BOV??  I have the DV24 version