I believe they are stating ALL the way IN (max feed) and then back it out 8 turns. So you are pretty close.
17 - 11 = 6 turns out (approx.), you are in the ball park.
You have to put it on MAX Heat required (turn the thermostat up) and get it burning/feeding max and set it accordingly without pushing hot coals off the end and have about 1" of ash on max feed. Start at 4-6 turns out, If you are pushing hot coals off, back it out 1/2-1 turn and continue until it settles in (May take you a couple hours).
Then that is the optimum setting. Every stove is different, so what works for one, may not for another. You have to do your own trial and error.