Can you loose boost from a B O V

[Prof]

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

If it leaks it\'s likely it would at idle too, and hence it should have vac on it and not positive pressure.

[SmbFD3S]

No i mean, the y-pipe is permanantly under positive pressure at idle... If you take the BOV off the y-pipe completely leaving it open, there is air coming out rather than a vaccuum....

[Prof]

I\'ve looked at the diagram for the twin turbo setup so I think I know where you mean.
 
On the FC we have to use the DV26 or the air leaking in the BOV will kill the idle.  I suspect that maybe because the FD has 2 turbo\'s it might have a surplus of air and the stock bypass valve or BOV is designed to let that out, so you use the DV24.  But presumably once it starts to build boost, the source of boost from the manifold should hold it shut until you let off the throttle ?
 
Maybe try a different vac source on the manifold or check that your line to the top of the BOV isn\'t leaking or blocked ?

[TTMan]

ben ive got a new hks ssqv bov coming soon you could test with if you want?

[SmbFD3S]

I\'ve looked at the diagram for the twin turbo setup so I think I know where you mean.
 
On the FC we have to use the DV26 or the air leaking in the BOV will kill the idle. I suspect that maybe because the FD has 2 turbo\'s it might have a surplus of air and the stock bypass valve or BOV is designed to let that out, so you use the DV24. But presumably once it starts to build boost, the source of boost from the manifold should hold it shut until you let off the throttle ?

Yes pretty much
 

Maybe try a different vac source on the manifold or check that your line to the top of the BOV isn\'t leaking or blocked ?

I would second that, it\'s much more likely to be a vacuum leak from a pipe or the y-pipe connection from the turbos, or intercooler hoses to be honest.
 
Can you describe what the boost pattern is like? i.e. whether you have full boost on first, or dropping off and the changeover pattern to second?

[neil_jdmr]

I blanked of my bov when i thought the boost issues could have been caused from there but with a pfc pip sorted those out. Still running no bov now on stock seq twins and imo feels like the primary picks-up a lot better than running with bov.
 
I have tried a good few times and on the pfc and my gauge the primary always achieves full boost quicker imo. Although in truth there is not a lot in it timewise
 
Plus i couldnt stand the constant whistling when starting to build positive boost with the stock bov.

[fil_auto]

Interesting thread and read is this guys - something else I can try to see if it helps to fix my boosty woes! #;o)

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

[rx7ben]

Well ive tested it with three different bov"s all with different hoses now and its still the same, so defo cant be the bov. I will try the method of not useing the bov see if that helps. Interesting to no that it could be the boost gauge. I have a cheap one from halfods so i will block this off aswell.
 
Thanks for all the input guys really helps a novice like me.
 
Would anybody no where i could get some of those blanking rubber caps from.
 
 
Cheeeeeeeers