There was only some 3-4lb of lump in there for a clay saucer test, and trust me, last time i tested with a proper load i couldnt keep it under 300 while empty no matter what i did with the vents:)
Even with that small load, i went from 2 vents just cracked @ 240 to having to add more coal and run said vents wide open, just by adding some ribs on the top rack. Naturally, it kind of surprised me that so much extra heat was needed to compensate for the meat
So, how much extra heat does it really take to compensate for a sensibly loaded smoker? 50 degrees or so? I imagine the requirement dwindles as the meat goes up in temp.. but what's the curve look like?