I run a Forge FMCL007P BOV, I am using a switched low boost / high boost set up with the BOV spring set up to the high boost value (20psi).

I am concerned that the BOV will not be operating correctly at the low boost value (10psi), however, when I started to research into how a BOV works I found this:


How do I adjust the spring pressure to suit different boost levels?
You don't need to! At full throttle there is equal booost pressure on both sides of the piston, so it doesn't matter what boost level you are running, the pressure balances itself out. It then requires very little spring pressure to stay shut. The spring adjustment is used to match the VACUUM signal of the car. The idea is to adjust the valve so that the piston remains just closed at idle. This way, when you lift off the pedal, the spring will be neutralized so that the boost is free to push the piston open.


I assumed the spring psi strength was for boost not vacuum, If the above is correct and the spring psi value is for vacuum only, am I right in thinking that if I fit the weakest spring (5-15psi) and get no vac leaks at idle then the BOV will work perfectly at my 2 boost levels?

Barry

 

Cancel that, I understand it now!

Barry