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This has been covered so many times I know it off by heart
10 to 12 psi is considered "safe". I run that, thing goes fine
IF it has indeed been hiflowed (I would get someone in the know to check this for you, someone in the club enarby to you will be able to help ) then more the 14psi is certainly possible.
The BOV laws really depend on which state you're in. In NSW, they are illegal to have them venting to the atmosphere, and they also cause stalling issues with the standrd Air Flow Meter, and the car runs better when it is plumbed back in