I just got my Blitz BOV DD and all instructions are in Japanese!
Plus I have never ran a aftermarket BOV.

Wondering how easy should my BOV open?
Should it open under light throttle while in neutral?

I got under the hood and pulled the throttle cable and when I release the throttle even lightly and slow it opens a hair. Then the car surges. I know there was almost no boost when I did this.

Should I tighten the screw?

 

Try tightening it to increase spring tension which may prevent what you're seeing.

 

I will.
I'm curious how much I need to adjust it before I go adjusting it with no idea of how it should operate.

Can someone with a properly adjusted BOV tell me when it should open. (I know when you let of the throttle dont say that)

 

since a bov is to release pressure before the compressor you should be in boost before it should vent.

 

Wrong

 

If you hear it its working... lol. I had a greddy type s that had to be adjusted like yours. I was running mine open loop(not vented back into the intake) so I had to adjust the spring tighter to prevent surging at idle. Are you still running stock boost levels? If so keep the spring adjusted in the middle area( tightness) but adjust it accordingly so your BOV doesn't leak or so you don't overtighten it and get compressor surge.

 

It should not open until manifold vacuum is lower than it is at idle. If it opens at idle the engine will run like crap because of the huge air leak.

 

I know it's working I already said that.
I can watch it open form under the hood.
Also it doesn't open at idle by itself.

My question was how easily should it open?
Should it open everytime I release the throttle regardless if there is no boost.
And regardless of how much throttle or how slowly I let off.
Like when just cruising and I back off the throttle a bit should it open?

Can I make it open only when there is some boost because the car surges when the thing is open.
I only want it open when it has to be open.

 

Also when it opens if I dont hit the throttle it wont close all the way for a wile giving me crappy idle for a couple seconds.

Should it open and then close shut imediately.
Is this a sign the spring needs to be tightened?

 

I need to know that too, i just got my sheepdog BOV
and it's sooo shy and sooo quite, it open when there is boost ( which is good) but it'S sooo quite,

 

^

 

i have my blitz BOV adjusted like so:

losten the screw till it becomes a vac leak then tighten it one half turn

works fine for me

 

The BOV should NOT open when you are on boost.. or else you'll just end up leaking the boost to athmosphere rather than making use of it.. the BOV should however open up when you come off boost and into vac.. the stock BOV starts to vent boost pressure when vac hits 15in/hg ....

 

Man is no one reading what I am posting.
I know it shouldn't open when boosting.
Read before you post please.

Can anyone answer my questions above?

 

BOV's are very simple devices. They will open every time the pressure in the manifold is slightly lower than the pressure in the pipe the BOV's mounted in. The pressure difference has to overcome the internal spring tension. You can set that tension so it doesn't open at idle.

 

I've got a stock first generation Eclipse BOV. Or a 1g DSM BOV for those who know. The damn thing works PERFECT. It opens when its supposed too, doesnt leak or any malfunction. Its not adjustable though. But the best advice I can give you is make sure your BOV is good and sealed at idle and tighten some more from there. Do you have a boost gauge that reads vaccuum and boost? Cause what your gonna have to do is probably make runs down the street and adjust it where you feel is right. Their honestly not that complicated like NZ said.

 

I have a boost gauge.

Just not sure how much tighter it should be after you get it to not leak on idle.

Also the BOV shuts slowly sometimes, is that normal or should it shut right after it vents?
It slams shut if I hit the throttle after it vents, but if I pull the throttle cable and then let it go the BOV stays open a bit for a moment.

Can someone who adjusted an aftermarket BOV please give me a writeup on how it's done properly.
Not just say it's simple then not explain.

 

My english Instructions say "Since different engines have different vacuum pressure, set the BOV so there is no air leak from the out let at idle. what I did was, drive and stay off the boost and if it went off then I stopped and tightened it. Repeated untill it only went off under boost. (not under but after I let off)
It should not stay open ever! Open and close thats it. maybe it gets stuck?

 

Thanks I'll try that.

Is yours a Blitz BOV? If so how far in is your screw.

 

Dude, I have an HKS SSQV. I set the set screw as loose as it would go and I don't have a leak at idle, nor does my car run bad when it goes off. When I let off the throttle, it opens relatively quick and closes slower but closes all the way. When I set mine, I turned the screw most of the way out and then turned it in until I felt contact and tighened the locking nut. I made it tighter today and it's much harder to get it to blow off. I'm not making boost right now cause I'm trying to break in a new motor, but BOV is very audible from inside the car. That's about all I can tell you.

 

Nope. Not Blitz. I have a Greddy. I have the same screw and locking nut. It's supposed to close right away, otherwise you would leak. Try some lube, to help it open and close.