spent quite some time looking for this. no one i asked seemed to know, so maybe this can help someone else. worth noting, i have seen this value incorrectly identified in a different location in other tuners files.
in 16bit, search for 0006 07D0 0FA0 1770 1F40 2710 3A98, this seems to be axis data for Offset zur Korrektur der Tachovoreilung, Offset to correct the speedometer, should be a 6x1 map of all 0000.
few bytes past that map you will find your limiter. may be 1x1 or may be several bytes. 61a8 for euro files, or 4e98 for usa files. 250km or 201.20, 120mph basically.
.01 factor in km/h.