Lowest boost for BOV
 

What is the lowest boost that a BOV will open up on? I can rev my car to 6k and let off on the gas and I hear compressor surge. In neutral reving to 6k I get 3.5 to 4psi of boost.

The spring is as loose as it gets. Do I have to be driving for my BOV to open?

Re:Lowest boost for BOV
 

do you have the vacuum lines ran into it?

Re:Lowest boost for BOV
 

Vaccum is ran to a T from the intake manifold.

Re:Lowest boost for BOV
 

try running a bigger line to it...what kind of bov is it?

Re:Lowest boost for BOV
 

It is a Blitz SS BOV. I am running 1/4 fuel line for vaccum to the BOV. Shouldn't that be enough?

Re:Lowest boost for BOV
 

I always thought that a BOV wouldnt open unless the engine was under load, just reving it with the car stationary wont open it?

Re:Lowest boost for BOV
 

I think that depends on the BOV and what car its on.

Re:Lowest boost for BOV
 

BOVs work of vacume wich is always present in the manifold when the throtle plate is closed.If your car is not turboed yet and you want to see if a BOV works you can just pull a vacume line off your manni. and that vacume will open the valve.This is how you can test your "junk yard" BOVs to see if they work.If your BOV is not openning then somethings wrong.

Re:Lowest boost for BOV
 

What do you mean just hook vaccum to it? I am turboed right now. If what you say is right then the valve would stay open because at idle.

I think that the BOV has to see a load for it to open because if not, it would just bleed off boost at wide-open-throttle. The Blitz also came with a hard spring for high boost. What is the average setting on low boost springs on BOVs?

Re:Lowest boost for BOV
 

How would it leak at wide open throttle if there is no vacume pressent to open the diaphram.There is only pressure present at wide open throttle.Vacume is created couse the engine is trying to suck air frome where ever it can at idle or when the throttle plate is closed.Only when the throttle plate is closed will it have vacume.If it is open(wide open throttle) then you have pressure not vacume.So if the bov works on vaccume at WOT it would be closed........right?

Re:Lowest boost for BOV
 

Fixed the problem, the holes in the vaccum tee was too small, so I bored them out.

Only opens after 5psi. Now keep in mind that this is only when I rev up in neutral. I can rev up to 5psi in neutral. It opens a little at 3 and 4 psi but it doesn't open up enough and I can still here compressor surge.

Is this normal or all BOV's like that?

Re:Lowest boost for BOV
 

I find this whole "getting 5psi in neutral" deal much more odd than the compressor surge... Who can build boost in neutral? What car / turbo? I knew/heard that some VW's running that tiny kkk03 deal could, but my t3 doesn't build a pound in neutral and I'd be hardpressed (but i can) to get my BOV to sound in neutral.

Re:Lowest boost for BOV
 

b16 is confusing himself and everyone else.

BOVs are open with vacuum. they close at WOT <--- NO VACUUM

i hooked my BOV up to my car when it was NA and reved it a couple times and the bov opens and closes.

maybe that bov is made for a race car or something? i have no clue

Re:Lowest boost for BOV
 

Sorry for the confusion guys. I fixed the problem; the ports in my vaccum T were too small. I opened them up and now I can enjoy the loud crack of the wipe sound of the BLITZ SUPER SOUND BOV!!!! MUUUUHAAAAHAAHAA!!!!

Still get a little compressor surge under 3psi but I think that is normal.

Re:Lowest boost for BOV
 

how can you be using a 1/4" line and still attach the vacuum line to the bov?

why i ask is because im having the same problem, i get flutter, or compressor surge at all psi with my hks ssqv, and im running 10-12psi. so maybe the vacuum line is just too small?

Re:Lowest boost for BOV
 

Yes, the vaccum line is too small. I have upgraded to 3/8" fuel line for the vaccum line to the BOV. I know that the 3/8's is bigger than the nipple on the BOV but 3/8" ensures good air flow to the BOV.

This is another "less restriction the better" situation. I put hose clamps on everything and have noooooooo problems. ;)

Re:Lowest boost for BOV
 

Oh yeah, make sure the holes in the vaccum T are close to or the same diameter as the 3/8" hose. And no you don't have to use fuel line (expensive); I just used it because everything is very close under the hood and I didn't want something like fish-tank line to melt. 8)

Re:Lowest boost for BOV
 

hmm how do u hear for compressor surge?

Re:Lowest boost for BOV
 

Its fluttering of the turbo. Very noticable.

Re:Lowest boost for BOV
 

haha my bov opens before boost.. like in 5 inhg it opens and a small psssshh

and it whistles a bit if i partial throttle and about 12 inhg vacuum

haha my bov is badass, opens so early

Re:Lowest boost for BOV
 

what kind of blow of valve are u using? fluttering sound? .....i have yet to hear how it sound like.......so what kinda damges will it do?