No Compression Surge Or "flutter" With Blocked Bov

[XGTRX]

Did some quick calculations on my rb20 rec-valve,

Valve seat is 1" diameter = 0.785² inches x 14 = 11lbs

Diaphragm is 2" diameter = 3.14² inches x 14 = 44lbs

estimated spring pressure 10 lbs

so when at 14 psi boost, there is 44lbs pushing down from the diaphragm, 11lbs pushing up on the valve face, then add another 10lbs down for the spring

so thats about 54lbs down compared to the 11lbs pushing back up from the 14psi of boost.

To see how that changes at intermediate throttle positions you would need to put another pressure gauge before the butterfly in the throttle body, needless to say as soon the plenum approaches atmospheric pressure only the spring will be holding the valve closed.

Please correct me if my physics is off

Sounds right, but I question the stock BOV's efficiency at evacuating the pressurised system TOO efficiently. I may be wrong but the lack of evacuation efficiency that a system has with no BOVs might actually be a blessing by more pressure remaining the intake system therefore helping part throttle response and turbo spool recovery.