I just finished up the NB and did a few mods, baffle, lowered the vent, raised the fire grate, built a basket, added some wheels, thermometers at grate level, new handles and table slats and a paint job.
Well I fired it up on St. Paddys Day and things didn't go all that well for me. I had a hard time keeping the temps up even though I had a good fire going, it was a struggle. @16 hrs with a 10# brisket, at 2AM it was on 170* internal so I foiled and put in the cooler. Finished them off in my drum smoker today.
Any firebox mods I can do?
Things I will be changing: Raising the coal grate @ an inch higher (4" clearance now) Re-do the Baffle to widen the opening.
Iv'e also read (as I don't have first hand experience) there are a few more things that might help to hold the temps better.
"Inverting the fire grate they give you. Take that grate, invert it, and place it on the last set up risers on the firebox. This will give you more clearance underneath the fire so you can reach 200+ degrees and maintain it."
"A door gasket modification can be made with simple high heat silicon. Wipe Vaseline around that edges of the cooking chamber when the door meets the chamber. Next run a nice bead of high-heat silicon inside of the door where they both meet. Close the door tightly and allow for the silicon to set up. After a day, open it up and you have a door gasket."
Put four large bricks in the cooking chamber next to firebox to act as a heat buffer and minimize temp drops during fuel reloading