I run dual stacks mounted on the outside equal to just above the lower rack but all the diminsions and ratios are straight from the calculator. The only time I have ever experienced "stale smoke" was when I overloaded my FB and then cut back too far on the intakes in an attempt to grab some extra sleep between fueling on an overnight cook. I starved the fire and ended up with smoldering wood that was not completely igniting and yes that was some crappy Que when all was said and done. To answer your question you first hand could find a a buddy with a set up with a flush top exhaust and insert a piece of rolled up gutter flashing that will extend down to the lower grate. After taking some readings during a test run remove the extension and take some more readings without changing anything else. The exhaust location should not effect airflow but rather overall potential temp zones inside the cooker. You may find that one design results in temp zones you prefer over the other. Only thing I would say is when you pull out the inside extension you put it back as an extension on the outside so that the overall exhaust length is equal during the whole test process just. If yo ugive this a try post some results and we can put this one to bed.DUAYNE B wrote:I think where people come up with stale smoke is when they dont have a finely tuned cooker
Mo Smoke wrote:My bad bro...I read your last post again and you did say that you control your temps with the FB inlets. I just missed it. The last thing I can think to ask is have you tried building a smaller fire? Check this thread.
Temperature Variation in RF Smoker
viewtopic.php?f=11&t=1505
Quick question for you.. How much difference are your temps from top to bottom? Mine won't be quite as long as yours so I hope left to right temps won't be that big a deal, but Since I have 3 racks roughly 5-6 inches apart, I wonder about the difference from rack to rack.