Hi, ive installed S4 cams about 2 weeks ago. After 10mins. of cams install we have tested cylinder compression. 12bar everywhere. After a week of break in the cams, we have tested compression again - 10 bar on all four. Anyone know whats the problem?

Manual says 12.75 standart, 10.78 minimum.
PS: Its JDM 10:1 DE, stock ECU. It was on 16° for a week and change it to 15° as JWT recomend. Running 100octan fuel (93 RON in USA?).