Where did you even get those numbers from?

0.83   1.87   -4.08   0.90   6.29   8.20   12.03   13.89   15.07   13.52   10.61   7.95   5.53   6.16   8.11   12.97

That's the percentage difference of your numbers.  Makes no sense.  No logs either.

Post your file too.  I bet fuel or timing hasn't been changed.  How are you commanding 1.6bar?

I suggest you look at this as well, the LDRXN tool makes sense of mbar-LDRXN

http://nefariousmotorsports.com/forum/index.php?topic=13189

OR right from the guide

"requested boost=10*(LDRXN)+300mbar

EXAMPLE:

LDRXN=195
10*195=1950
1950+300=2250 "

https://s4wiki.com/wiki/Tuning
but before making changes in LDRXN I would suggest you understand a couple more maps like LAMFA, KFZW 1 and 2, KFZWOP 1 and 2, LAMFA, KFMIRL, KFMIOP, and a few others, more boost without the fueling or retarded timing causes knock or worse in my experience anyways.