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
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
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
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.
Quote from: chrisrx7;616251are 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
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.
Quote from: chrisrx7;616300some 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 ?
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
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
thats a very good point nik i didnt think of that, i even run without one on mine
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
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...
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.
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.
Quote from: Prof;616511which 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
Quote from: SmbFD3S;616516Interesting, 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.
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....
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 ?
ben ive got a new hks ssqv bov coming soon you could test with if you want?
Quote from: Prof;616549I\'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 :)
Quote from: Prof;616549Maybe 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?
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.
Interesting thread and read is this guys - something else I can try to see if it helps to fix my boosty woes! #;o)
Quote from: Nik da Greek;616396Just 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
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