Update: my offset smoker ran 75 degrees hot at a Sunday cookoff in Waco and I lost to a guy with a drum
Last Sunday I hauled my offset out to a small cookoff in Waco, got set up at 6am, and by 9 the pit was sitting at 300 when I wanted 225. I chased it with the intake for two hours, overshot the other way, and my brisket came off dry at the turn-in. Judges gave me 6th out of 9, and the guy who took first was running a plain drum smoker he built in his garage. I've cooked on this offset for four years and never had it swing like that. Bad charcoal, a leaky door, or am I just fighting the wind off the lot? Anyone got a fix for a pit that won't hold steady?