With the vents 100% open at the bottom and a full chimney of lit charcoal to start, you MAY see temps that high, but once you put unlit charcoal on, the temp will drop and then they may spike. Each smoker is different, but for me to maintain higher temps I choose not use the minion method. I may add a few unlit pieces every now and then, but I don't use the minion method that much. I choose to use the pre-burn method.
One thing you must do everytime is heat up the smoker before you add meat or other foods. I usually get mine up to about 375°F and then stabilize it to what I want for what I'm smoking. But the smoker must be brought up to temp for at least a half hour or so before the meat. Once the smoker is hot it takes less fuel to keep it there. Sometimes with too much ventilation I get temps spikes and billowing smoke when using the minion method, which is why I stopped using it. With my Brinkmann Smoke'n Pit Smoke King I make very few ventilations adjustment at the bottom, as a matter of fact I have none at the present ( I have 12 - 3/4" holes in a circle in the bottom of the charcoal pan, that has been the ventilation at the bottom for about two months now along with the sides. To lower the amount of air I block it with an aluminum dutch oven that fits perfectly under the charcoal pan). But, I mainly use the Stack Mod I came up with to adjust temps. Works great and I can achieve most any temperature I wish, I just have to babysit it. I don't have a problem with babysitting the smoker(s), if I did I would just buy electric (Traeger).
