What unit are these "Points" in? Atmospheres/bars? 6 atm is VERY low (88 PSI). If it just had arbitrary numbers on it, he's talking out of his ass. 9 atm is 132 PSI which does sound more like what it should be. You dont always get smoke from an exhaust if you have bad compression. You can have poor compression but no smoke due to bad valves, valve seats, or valve timing.