Whats up guys. I am running a trick turbo kit with a Turbosmart Raceport BOV(the black one). Ever since I installed the kit my BOV has always had a flutter noise when letting off the throttle, at least I think its coming from the BOV. I just assumed it was normal. When I got the truck tuned, the tuner asked me if I had a weaker BOV spring and said the one in it was a little to stiff but it would work. Well that was a while ago, and it sort of slipped my mind. Well today I felt like when letting off the throttle I heard this light howl sort-of kind-of noise coming from the turbo area and this got me thinking about the BOV again(I am paranoid about noises lol) Is that how these BOV normally sound or is this turbo surge?

 

How much boost you running?
Spring in BOV needs to string enough to stay close while cruising.

 

Just 9 for now. I thought it couldn't open unless the throttle body was closed?

 

Could I just look at the vacuum I am pulling on my boost gauge to decide what kind of spring I need?

 

Correct
Bov uses psi difference to open.
Vacuum on top boost on bottom
It opens.
Boost on top and Boost on bottom
It's Closed.

If the bov is opened under boost.
There's a leak in top. Either vacuum line. Plug left out. Etc.

Unless you have a Wild cam in there spring should be fine.
Better to have it heavier then weaker.

 

No flutter noise while in boost. Only when letting off.

 

i find on mine the low boost 2-3psi wont open the bov fast enough so you will get surge though the turbo a little.

 

Do you get your vacuum reading at idle in park or in gear?

 

i run on speed density my bov is open at idle...i had the heavier spring (closed at idle) in but was getting the same bov flutter so was told i should switch to the lighter spring to avoid turbo damage

 

So would that be pulling in unfiltered air into the engine?