Yeah it's sorta like someone exhaling through their teeth with a bit of a whistle to it, and doing it in a stuttering manner.

Unless that's not surge? Maybe that's just the boost isn't as strong as the spring on the BOV and it's only letting it out in short bursts because it barely peaks above the spring's set PSI load? Sorta bumping against the threshold?

 

So should I pop in the softness springs for my BOV? I believe that would be green.......

From hardest to softest:

RED
BLUE
YELLOW
GREEN

 

Is the green the softest or the yellow??

 

Green, he has it right.

 

Ok, I popped in the green spring and tried it out but it seems at higher boost it still makes multiple whooshes....low boost its fine.

What can be done???

 

Something else is clearly wrong.
check the sealing of the bov piston. Just push the piston in with your finger and then block the vacuum port and see if it holds.

Which piston style do you have?

 

When I uncover the I top I checked the two o-ring and they are fine......I have the piston with grooves on it......

 

Doesn't mean they are sealing.

Which way do you have the valve installed? vacuum port up or horizontal.

 

When I had it brand new with the blue spring, I tried both ways up and sideways......Both ways sound the same.......

Now, with the green spring I put it horizontal.......

 

Well all of the springs (Green, Yellow and Blue) open easier then the stock bov so I don't see it being the problem. Which leads me to the only way that valve could have a problem and that is the sealing of the orings. Was that piston the way you brought it?
I have the blue in now and even though I have the stock aibox back on, I know it's not surging because I can still hear it a little and you can usually feel it while driving. I am guessing you replaced the vacuum hose with a longer one with the valve that way? (That is the best way to install, btw..)

 

Hmmmmm, then I dunno whats wrong. And yes I did buy a longer tubing so it doesn't crimp.

So are you saying that my BOV is defective?

 

The only way it can be is if the o-rings don't hold a vacuum or for that matter pressure. The valve is a simple design, which is why it is so effective. The spring holds the piston closed to around 10 in. of vacuum. Therefore it is open at idle and closes as soon as the engine vacuum drops below 10. Under boost, there is the boost pressure and the spring pushing the piston to the seat. Of course there is boost pressure countering this on the piston face so it is essentially just the spring that is holding it closed. As soon as you lift off the throttle engine vacuum jumps up to it's highest point at about 20 in. That is considerably more then needed to counteract the spring and open the valve. That coupled with the boost pressure in the IC tube is more than enoug ht othrow the valve open and engine vacuum will kep it there. The only way that valve will close and open (fluttering) again if the throttle is still closed completely is if the orings are not sealing properly. Then the vacuum is lost in the valve due to the leak and the piston seats again and as soon as there is some boost pressure again and the vacuum that is still possible to act on the piston it will open again.

Do you happen to have a boost/vacuum gauge in the car?

 

Yes, I just bought an Autometer boost gauge but haven't installed it yet because I dunno how!!

 

Just to clarify something I have found from talking to people the last couple days. We should be looking for "flutter" at WOT, not at part throttle. If the spring has flutter to it at WOT, step down one step in springs. If the valve releases pressure at WOT at higher RPM, go up one step in springs. With the VTA on our car we get slight flutter on part throttle or low rpm when closing of throttle body, which is not a problem due to lack of boost pressure acting on the piston. For example, Imagine if you are releasing 5 psi vs. 20 psi at WOT and how that pressure is acting on the bottom of the piston as it pushes the piston open along with the vacuum pulling the piston open. AT WOT, it is a smooth opening and release of the pressurized air. Does anyone have experience with wastegate flutter and how that sounds in the car? Wastegate flutter is a common problem on cars with boost controllers, either manual or electronic.

 

I've noticed low speed flutter upon slow release of throttle while shifting... Is that what you mean?