BOV Setup for your N54
- Thread starter Chris@VargasTurboTech
- Start date
@Chris@VargasTurboTech a pcv tech article would be great as mentioned above. There are extensive discussions on this but an organized breakdown would help I think.
That's doable. There are a few guys out there that could talk about this intelligently, Rob Beck being one of them, but I'm not adverse to the idea of writing that sort of article if Rob doesn't beat me to it. 
Chris
Chris
Just saw this. The article was about BOV's on N54's... we just don't see that sort of damage on these motors. In fact, we have yet to see compressor wheel damage caused by surge directly. Not saying it can't happen... saying we haven't seen it here.
Someone really should. As I feel there is a lot of misinformed people out there on this subject. A lot of people don't understand how the system actually works, and what changes should and should NOT be made to the system.That's doable. There are a few guys out there that could talk about this intelligently, Rob Beck being one of them, but I'm not adverse to the idea of writing that sort of article if Rob doesn't beat me to it.
Chris
For sure. There are a lot of very knowledgeable guys on this platform, and not just speaking in-house. Rob's PCV solution is solid and in general I acknowledge and respect Andy Diver's out-of-the-box thinking and products. There are a few good takes on it. I'll add it to the list.
So what's been the consensus on this? My car is much like Tyler's, vacuum varies a bit with AC on/off. I'll vary between -8 and -6 psi. I'm on the unpainted stock spring but get slight flutter at low boost. I feel like the black spring is too steep of a jump so I may try the white spring first. I'm FBO on stock turbos, already tapped my manifold with a brass fitting.
Black spring works great for me anyway. Even a 1 psi spring will keep the BOV closed, the moment the vacuum disappears(accelerator is pressed) the only force is a 1 psi spring pushing the plunger closed. When you go into boost, its apply equally to both sides of the plunger so it cancels out.
If your turbos create more than 1 PSI of boost in a vacuum situation or if your vacuum is greater than 6 PSI, then it might be open a bit, but at that point air is being forced out of the bov and nothing is going to fall into the intake tract so I feel no need to shim the spring, but thats just my opinion. I'm curious why it needs shimmed actually...
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It doesn't have to be shimmed. That's for the people who open BOV at idle bothers. From Tial themselves, it's normal for it to be open during idle. I.e. this is a non-issue.
Here is another scenario that I think I'm experiencing all due to not having a trial set up correctly..
So I'm running a tial but with out a 1/4 signal like it demands.. I just havnt had the time.. So to reduce surge and delay I went with a lighter spring.. So now the BOV is open at idle.
Fast forward a few months and I'm noticing really really inconsistent boost targeting.. New solenoids,thought I fixed it. Nope.
Re ran all my vacuum lines to fix a couple that were kinda collapsed. Nope.
Check for boost leaks as in nut and bolted all connections. Nope.
I'm almost willing to bet that the lighter spring is being over come by boost.. Havnt proved it yet but something is telling me that's what's up. With out the 1/4 signal pascals law can't play into affect with exerting the force equally against the valve from manifold pressure
This may be debunked as soon as I post it but I feel I'm on to something lol
So I'm running a tial but with out a 1/4 signal like it demands.. I just havnt had the time.. So to reduce surge and delay I went with a lighter spring.. So now the BOV is open at idle.
Fast forward a few months and I'm noticing really really inconsistent boost targeting.. New solenoids,thought I fixed it. Nope.
Re ran all my vacuum lines to fix a couple that were kinda collapsed. Nope.
Check for boost leaks as in nut and bolted all connections. Nope.
I'm almost willing to bet that the lighter spring is being over come by boost.. Havnt proved it yet but something is telling me that's what's up. With out the 1/4 signal pascals law can't play into affect with exerting the force equally against the valve from manifold pressure
This may be debunked as soon as I post it but I feel I'm on to something lol
You know, I figure there is going to be some variance here. Pressure signal from a small house vs pressure pushing up against the entire face of the plunger... Not really sure. But with boost targetting, one thinks wastegates lines first. Right now, I'm about to jack up my car because I think a plug on the bottom port of my tial has come loose or something weird like that.
It's purely a hunch that I havnt looked into yet.. In the end the vtt2+s that are going on in the next couple months the will probably be what solves it lol..
My stockers are exhausted!!!
Its just odd how it hits targets sometimes and dosnt others.. Maybe I've just never dealt with a tired set of stockers that are being asked to target high (for what they are 21lbs)
My stockers are exhausted!!!
Its just odd how it hits targets sometimes and dosnt others.. Maybe I've just never dealt with a tired set of stockers that are being asked to target high (for what they are 21lbs)
If you go with the lighter spring and have lots of throttle closures, it could very well be the BOV venting making your boost drop after the closure. Make sure you've turned traction control off/etc and log log log to see what's going on.
Yea at first it was all good the stockers spooled like the should down low and hit the 21 psi like they should (but really shouldn't lol) now as the spring has seen tons of heat cycles it could have very well fatigued just enough to cause trouble..
Meant to bring home a stiffer spring from work last night but forgot.
I would fix the tune, not change the spring. Or be more discerning with traction control/right foot.
Just to clarify and I'm trying to sort this out now.. In the document above it states to choose the lightest spring available that still keeps the valve closed at idle..
In the video he states you will wind up with a spring that has the valve open at idle..
Maybe I'm posting this prematurely and have to read it over a couple times.. But with a trial valve.. What's the rule?
In the video he states you will wind up with a spring that has the valve open at idle..
Maybe I'm posting this prematurely and have to read it over a couple times.. But with a trial valve.. What's the rule?
Tial states that it's normal to have the BOV open at idle. This bothers some people, and for them we suggest shimming the spring (not going to a different spring) until it's JUST shut. Mine is open at idle.
After i installed ps2 hybrids and relocated inlets, a strange noise developed @ low pedal input, i changed my tial spring to the white one, still a noise, like a owl hehe! Than i did the things above like Chris wrote, tapped a nippel in my mani for a direct vacum line to my bov, still a little bit of owl sounds, so today i changed my spring to the black one, the noise is gone! Just want to report my experience.
Greetings
Roy
Greetings
Roy
Black spring FTW. I honestly don't know why anyone tries to run tighter springs. Can someone enlighten me? And don't tell me because stuff can get into the BOV, that isn't gonna happen, and i'm sure some kind of filter can be devised to ensure that.
I'll be installing the plain spring tonight. That is the spring tial calls for with my 20in of engine vacuum and a 1/4 signal.
See how it goes.
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