Functional BOV yet still turbo chatter

[Stabmasterflex]

BOV opens and functions with higher boost (5-15 psi) but still get the whipple chatter noise from the turbo. On less then 5psi I don't think the BOV opens. I've rebuilt my BOV, no change, then I installed another one. No change. I did find a vac leak on my t-body fixed that and still no change. Any ideas?

[Jaxx_]

where is the bov located?

[ak-]

Sequential BOV or adjustable?

[Cronopoulos]

What wastegates?

[Dj Buttchug]

you could be hearing wastegate chatter. Internal or external wastegate?

[Stabmasterflex]

Adjustable "rs type" bov. External wategate with boost contoller. Bov installed 8" before airflow sensor.

[LowR3V'in]

The spring is too tight if it doesn't open at 5psi.
Adjust.

[Stabmasterflex]

I'll give it a try. I removed my boost controller no change. I'll see what happens tomorrow. Now I need to get a vac line restrictor for my begi.

[e30leigh]

carefull with the spring pressure. too loose and it will be pushed open by high boost.

[Stabmasterflex]

I loosened it off. No change. Removed boost controller and no change.

[ak-]

what engine are you using and where is your vac line T'd to?

[Dj Buttchug]

Adjustable "rs type" bov. External wategate with boost contoller. Bov installed 8" before airflow sensor.

guess what op. I have the same type rs knockoff. they all do that, I cant blowoff unless i build over 13 psi.

The spring needs to be adjusted/ modded/ cut and stretched or buy another spring. basically with these bovs you get almost a SSQV type sound unless you build enough boost pressure to pop the bov all at once.

[maniacmatt]

I don't know anything about your particular BOV, but if it is an ebay knock-off that could be your problem there.

I'm not sure how yours works, but with my TiAl the spring you choose (not adjustable) is determined by your vacuum at idle and is unaffected by your boost level. The spring just holds the diaphragm so that engine vacuum at idle won't cause the valve to open. Boost pressure from the vacuum line pressurizes the back side of the diaphragm and keeps the valve closed under boost, not the spring.

Two things you can try, not sure if they will work. Make sure you have a clean vacuum source for the BOV, my TiAl called for a 6mm I.D. line straight from the intake manifold, with nothing tee'd off of it or anything to interfere. Secondly, if it was me here is how I would adjust thhe spring. With the car idling loosen the spring until the BOV comes open at idle then tighten it slowly until the valve closes.

Does your boost gauge display vacuum as well? I am local so let me know if you want me to give you a hand.

[Stabmasterflex]

Hmm. If your the matt i think you are then you actually live in my subdivision. S52 turbo right? I talked to you on 50th street last week? Im going to give that a try. Makes sense. I keep thinking i may have a vac leak still which is also causing me a higher idle. Im up to about 15psi now and it certainly is blowing off, but if your saying its all coming from the bov and not the turbo then thats fine with me.

[maniacmatt]

Yes that's me. M52 though. I don't know exactly what the noise you are hearing is. My post was just what I would do in order to try and get your bov working at lower pressures. I'm not even sure yours functions the same as my TiAl.