My Profec B Spec II is set to boost to 0.75bar, which equals 75 kilopascals. This is well within safe limits on my car, I'm not 100% sure on the specs of the R32 GTSt turbo but 0.8bar (80 kilopascals) seems to be the upper safe limit.
The boost guages usually measure in kilopascals x 100. So it's really showing Bar.
I've come to the conclusion that 0.8bar is safest when upping the boost, I've not heard of anybody damaging a turbo at that pressure. 0.85 is regarded as the absolute maximum they should be run at and even then I've heard of more than a few self-destructing. Any higher and you're asking for trouble.
These are basically my opinions based on what I've read and personal experience.
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