When I drive with window open I hear "pshhh" noise from the back. I did not have 997T long enough and wonder if that is a boost leak I hear.

Yesterday I accelerated in 4th gear to see if I could read 1.2 bars of boost but the road was too short (and the speed limit was too low) and I could only see 0.6 shortly. If I were to have a small leak on one side, would I ever see 0.6 bar pressure?

How would I easily test for a leak? Would something like accelerating in 5th/6th gear from say 30mph to 70/80mph, pedal to the metal, induce 1.2 bars of pressure?

Plugs have been changed 3k miles ago.
2 months ago the car showed 573hp on the dyno (it has exhaust and Sportec software).

 

Went on highway, acceleration in 5th, 1.1 bar stable and goes like stink. In my book that means no boost leak. :-)