BOV Adjustment

[Structure240sx]

Im just getting my project started, bottom end. Well im starting to buy some of the parts for my turbo kit. I plan on running low boost 10-12psi then 15-17psi for high boost. I'm goin to be using a greddy profec b with those settings. Now will i be able to just swtich to high boost without adjusting the BOV? will it still open for that amount if its tuned for 10 psi?

and which BOV would you choose the old blitz super sound or the new dual drive?

[JJ240]

I think when you attatch the BOV to a vacuum line it wont open as long as your throttle plate is open. When your throttle plate opens the pressure in it will be put into the top chamber of the BOV and keep it from opening, but then when you let off the gas and the throttle plate closes there will be a vacuum running to the top of the BOV so it will open and release the pressure. So the more boost you run the more pressure there is holding the BOV closed when it should be,

[Structure240sx]

so thats what that vacuum line is for. any idea where it is connected to? there is a lil nipple on the throttle body i know of between the coolant lines.

[encasemyheart]

The BOV does not every need to be adjusted, unless you get a Greddy which can be adjusted for sound. You attach it between the intercooler and throttle body and the vacuum line goes to usually the intake manifold. When the throttle body closes the manifold has vacuum, which opens the BOV to vent excess air for reasons already mentioned about destroying the turbo and whatnot.

And the BOV (except the HKS unit, BEST BOV ever for this reason) doesn't hold tighter with pressure, it isn't designed like that, that's why some leak over a certain boost pressure, except the HK$ unit.

A BOV is a BOV for lower boost applications, my choice is a 1g Eclipse/Talon/laser BOV, $30 and works fine if you crush it.

[Structure240sx]

where on the intake manifold do you attach it to? i've heard about using the DSM bov but like i mentioned my bottom end is goin to be built, the rods and pistons are on their way, so i plan on running high boost upto 17psi on pump gas. if i ever do run race gas or alchol injection then it will go higher than that but thats much later. wouldnt the DSM bov not be enough for higher boost like that? so basically any aftermarket blitz, greddy, hks BOV will work the same for me right?

[encasemyheart]

Yes any aftermarket will be the same, the 1g bov won't hold more than 14psi I believe, but it can be crushed to hold past 22+psi, I wouldn't know if that helps you, but it will hold to that psi and possibly more.

For aftermarket I would recommend HKS first, although expensive. Then Greddy Type S, it's high quality and looks good. After that I would go with Apexi. I presonally don't like the sound of the Blitz, but that's preference. Basically unless you get the HKS and plan on running high boost, you are choosing between BOVs based on sound. DO a search and you can hear them all...

I'll look and try and find out where you attach the BOV vacuum tube on the KA.

[JJ240]

Just splice it into the line from the throttle body to the fuel pressure regulator

[C-Kwik]

Just splice it into the line from the throttle body to the fuel pressure regulator

From the intake manifold. Not the throttle body.

[JJ240]

Yeah sorry, do what i mean not what i say I was thinking intake manifold behind throttle body, but thats not what i wrote