Originally Posted by Bbq Bubba
Lose the door & your temp issues will be gone.
Yes, this is your problem. Any air leak will cause temp problems and I guarantee the door is leaking air.
I'm all about improving and trying new things, but you have changed so many variables that if some thing does or does not work as planned you will not know where to begin looking for problems or making changes, you'll just be guessing.
I would take 1 used drum, make only 1 change and test that out before making any other changes (a test should be more than one burn, more like 3-4). The drums can be made to look cooler and you can add bells and whistles but the basic design is right on the money.
keep us posted.