Mgdwj wrote:k.a.m. wrote:I like to go 10% to 15% larger. Basically if you plug in the perfect 100% and start enlarging the firebox watch your exhaust height when it starts to change you're altering the recommended 1/3 rule draft. Too much and you completely change the way the cooker performs. I am not saying this is a bad thing it is just something I do not do.
I had planded on going about 20% larger firebox. To much? I also plan on a vertical warmbox.
You will be fine at 20%.