The boost levels would depend on your setup; every setup would have different boost levels for the desired power level.
If your looking to 30 psi seriously in the future I would invest in a quality electronic boost controller that would display your boost at any level.
2004 SVT: bewst'd!
2010 Escape 3.0 V6
2004 F350 6.8L V10
1986 XR4Ti 2.3L Turbo, 15 psi
2007 ST ; formally bewst'd - R.I.P