RE: Dialing in a stick burner
IMO you don't actually want a slow burn, because there is always the danger of a smoldering dirty fire, instead of a small hot fire keeping your temperatures up.
Think of the fire base as the footprint of the fire you need to run your pit at a specific temperature, for a specific amount of time.
Raise your coals 2 - 2.5" with a log basket or charcoal basket.
Build your fire base of coals with a mix of charcoal and wood, and leave your exhaust as open as can be, while you heat up the cooking chamber. While you are starting the fire in the fire box, you can also preheat the exhaust in the cooking chamber, to begin the draft out of the exhaust, and start the draw.
Once the temperatures are stabilized, check the amount of fire you have in the fire box, in most small to medium sized pits, you require a fire 12" - 15" long, 6" - 8" wide and 1.5" - 2" deep of burning coals, some need more, some need less, this is the fire base you want to maintain, in order to keep your working temperature in the pit.
In order to maintain that fire base, you can add 1 or 2 splits at a time, about every 40 to 60 minutes, you can alternate between 2 if the fire base is shrinking and 1 if the fire base is growing, if you need more base in a hurry add a chimney or 1/ chimney of fresh light charcoal every 3rd or 4th refuel.
Once you get an eye for the fire base your pit requires to maintain a specific temperature, you can also work in preheating your splits, stack the next refuel wood on or next to the fire box, this starts the process of off gassing, a precursor to combustion, when you add preheated splits to the fire, add it split side to the fire, and it should burn almost instantly, by having flame and heat immediately you reduce the dips and soars in the temperature that your pit is running at.
Depending on how these ideas help with maintaining a more even fire, you may be able to reduce the exhaust a little, not more than about 25%, then readjust your firebase to keep your temperatures.
A clean burning fire will put out a little smoke when you first add a fresh preheated split, but will settle into a clean burn again within a minute or two, and at that point you will mostly see heat shimmer at the exhaust, rather than billowing clouds of dirty, sooty smoke!
Do a couple of test burns in good light and pay attention to the temperatures, and the volumes of smoke or lack of it that you get with different fuel loads on that fire base.
Respice, adspice, prospice. Latin proverb.
Respice = you didn't use enough spice the first time! adspice = you ought to add spice, you know? prospice = you should be an advocate for spice!
KCBS Certified Barbecue Judge.
UBBQO Certified Barbecue Judge.