1g BOV theory?

[1fast4x4]

I built this car 10 years ago. Blew it up so it sat for 6 years until I fixed it about 6 months ago.

I was getting tired of the whistle my crushed 1g bov made when I decelerated during normal driving so I put my stock uncrushed 1g bov on it and the whistle went away. I know why but here is the question about the crushing your BOV theory.

I know we crush them so they will hold more boost pressure. But, since the vaccum hose that opens the BOV has boost pressure when the turbo is making boost isn't the pressure on each side of the diaphram the same? If the pressure is the same why does it leak? Or does it leak at all, we just assume it does?

 

[JusMX141]

Crushing increases the spring's holding pressure by adding preload.

The Dodge Garage Mod caps off the valve's quick release feature.

Doing one or the other should help it to hold boost well into the 20's; doing both guarantees boost to be held over 30psi but can cause compressor surge and flutter as the valve is stiff to open at low boost. This is a common trait of all stiff "racing" blow off valves.


With the factory quick-release feature still in place, there's a center chamber underneath the diaphragm that is fighting to open the valve in addition to the pressure in the piping. By doing the Dodge Garage Mod alone, you should have no issues holding a streetable boost pressure.