Settings for printing HIPS?

I have been testing with HIPS filament.
Bed adhesion is OK with 100C bed temperature (skirt).
Layer adhesion stays a problem for some models.

nozzle temp 245C / 250C
I lowered the print speed from 20mm/s up to 10mm/s which improved the result.
Also making the layer thickness smaller seems to help. I ended testing with 0,12mm
Cooling fan off.

anyone with experience with HIPS? Do i have to raise the nozzle temp even more, or even slower print speeds?

in addition: no popping or burring. what comes out is nice and clean, except for some layers with adhesion problems. I work with an enclosure that stays closed at all times during printing.