BOV Setup for your N54
- Thread starter Chris@VargasTurboTech
- Start date
Yes, please do this. You will find out that you have made a mistake somewhere in your installation. If your plumbing is correct, it doesn't matter if you have 10 psi of boost or 100 psi of boost, that force is being applied EQUALLY to the top and bottom of the bov plunger. The end. This means they cancel out and even a 1 psi spring will break the tie and hold the plunger down. If this somehow is not the case, you simply have bad plumbing somewhere, like a boost leak on your top port. This isn't speculation or theory, it is just plain facts as Chris stated previously.
I'm pretty sure that hasn't worked. Maybe we are not smacking hard enough.
Filippo
Welll…. you will get some pressure drop from the bend and through even an open throttle body. But we're in agreement, it ain't a lot.
What? I don't see that anywhere on Tial's page.
(just kidding guys, I'm fucking around)
Time to go buy some beer and pretend the mountains on the can are blue.
Few questions,
-For having Tial bov open at idle-does it matter whether it open slightly or fully?is it better to have either.
- I have read having bov open at idle can get hot air/dirty air[contaminents]into engine.
Looking for a definite answer since I'm not sure what true to questions above.
-For having Tial bov open at idle-does it matter whether it open slightly or fully?is it better to have either.
- I have read having bov open at idle can get hot air/dirty air[contaminents]into engine.
Looking for a definite answer since I'm not sure what true to questions above.
If the valve is open, it means there is more pressure on the charge pipe side of things vs. the manifold. It's not a problem for it to be open. If it really bugs you, it can be shimmed to be barely closed. I just leave mine open.
i just checked mine and is at slightly higher then 20'' hg.At the time i did buy the recommended Yellow spring(20''hg to 21''hg/11 psi) & havent had issues. My TiAL Q BOV does stay closed but if its better to have a slightly open bov then ill put back the stock plain spring which looks like a 16''hg to 19''hg/10psi spring and maybe shim it.
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Here’s another question:
What’s better - a BOV that opens faster, or closes faster?
Comment: Softer springs like the black (6 psi) and white (8 psi) should open faster to a -11 psi or -12 psi manifold vacuum pressure upon throttle closure than would a plain spring (10 psi) or yellow spring (11 psi).
Accordingly the softer springs should release boost pressure faster than the stronger springs. In contrast, the stronger springs should close the BOV faster once the throttle plate opens, thereby increasing responsiveness.
So, what’s better?
What’s better - a BOV that opens faster, or closes faster?
Comment: Softer springs like the black (6 psi) and white (8 psi) should open faster to a -11 psi or -12 psi manifold vacuum pressure upon throttle closure than would a plain spring (10 psi) or yellow spring (11 psi).
Accordingly the softer springs should release boost pressure faster than the stronger springs. In contrast, the stronger springs should close the BOV faster once the throttle plate opens, thereby increasing responsiveness.
So, what’s better?
One directly corresponds to an increased likelihood of causing damage and the other does not. So that may ultimately be the decision given this context.
I believe this is a malformed question. Hear me out. The question presupposes the relationship of the spring to two consequences. Ideally we want a spring that releases boost pressure as quickly as possible when the throttle is released, and at the same time, we'd like a BOV which does not impede the building of boost pressure in the intake tract when throttle is applied and we are seeking to move from vacuum to boost. The spring itself is not the only factor. For example, one has the ability to shim the spring.
The second factor, at least in my very myopic experience - my car seems to transition from vacuum to boost very quickly. Could it be quicker? I suppose that's possible of course. On the other hand, with the stock Q spring my car was absolutely scary in certain transient throttle situations at significant to full boost. So I would say in my experience, there is a possibly nominal improvement (fast transient from vacuum to boost) versus a significantly scary-as-shit factor with the bigger spring at the other end of the problem.
I suppose that would lead me to say, along @doublespaces and @Chris@VargasTurboTech observations - run the lighter spring and shim as desired.
Filippo
Thank you both @doublespaces and @fmorelli for your comments. You’ve convinced me to experiment more with the spring pressure. Certainly the standard yellow 11psi spring which came with the TialQ is too strong.
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I went to local hardware store.they carry all sorts of things,sizes, etc.brought my tial bov in and found a exact washer that fits in perfectly,its called "Machined Washers".I bought a few different sizes and I got the 1.32mm to where it just closes and took a video with boost gauge it would open instantly with the stock plain spring that came with the bov.so jeffman try your local hardware store for one.
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Your saying that it responded so fast that it ws scary or was the problem a delay where turbos spooled and then the bov closed afterwards creating a light switch effect?
Basically ruining any granular control is what I was meaning by light switch.
There is no golden bullet for this problem because if you really look into it, there are situations when you don't want all your boost spewing out because you went down to 75% throttle in the middle of a sloping curve. There are repercussions for this and this is why the electronic bov is actually pretty smart.
That's interesting I would have thought heavier spring would help response but just risk turbine damage. The only thing I could imagine is that if the bov is open longer it could possibly allow the turbos to spin up freely before getting resistance and building boost but idk. With stock I would be under vac at low loads but with the hydras you will be pleased cause cruising down highway I name 2 to 3 psi in fact I was getting limps cause of over boost we had to reduce wgdc alot cause they just are always moving air. Makes Me wonder if I should gone with the 800s but then idk i think without the cams or head work the 650s are better than stock in every way.
Delay as in bov doesn't open in time or delay as in doesn't close in time. I have a feeling you two are talking about different things.
Yeah I'm doing a crappy job at communicating actually. I had several throttle problems, not one as I said. The other was jerky on-throttle behavior, some times. So that ... and off throttle delay. Both those issues disappeared with the spring change and 1/4" barb to the BOV.
Filippo
I think the quarter inch reference was the likely culprit as the spring would have been more surge I think. I was just testing my car on part throttle i made 4lb boost at 1500 rpm and 8lb at 2000 obviously cause turbos aren't stock but i was happy that it transitioned smoothly. However in 2md gear I got a neck snap on transition the ground was wet so I couldnt really go all out I will play around more but I think I may be having some issue from the plain spring possibly I have to check ,weird part is my bov idles slightly open with the plain spring if I remember correctly so I'm about crosseyed at this point.
