The calculator is giving you the maximum size you need for intake when it suggested the two 3" x 9" intake openings. Running on little to no intake is a good thing in my opinion it say's your cooker is drawing properly. You could slow the draft by 1/4 to see if that tames your heat a bit. but in all honesty if you can maintain a 250°/275° temp you are golden in my opinion.So Cal I am lighting the fire in the box with a torch,no charcoal ,just straight seasoned cherry wood . I was just concerned about temp, and the fact I'm only using one quarter inch gap on one side of the fire box. The pit calculator called for two vent holes 3x9. It is what it is but just seems I would need more vent open. It doesn't take but a few minutes and its up to temp