1. add lining of ceramic.
buy pottery clay, mix with water to mud, add inside, thickness 1", natural dry, fill in charcoal in main body and fire box, burning for 3 days.
2. chang to reverse flow
3. add motorized spit rotisserie
4. power draft like stoker or CyberQ
6. heat insulating blanket
7.a grease catching grill to avoid grease fire