I read a few suggestions on smoking trip tip. Remember, smoking meat is smoking. Not cooking meat. Anyone that is smoking meat over 225 degrees is not smoking meat. They are cooking the meat. Smoking is a slow process. If you do not have the time then do not bother.
3 lb tri tip.Do not, I repeat, do not purchase trip tip that has had the fat trimmed or removed. Fat side up in smoker. Make sure meat is at room temp. Many dry rub recipes online. find one you like. Dry rub the meat, wrap in plastic wrap, tightly. Place in refrigerator for at least 5 hrs. Remove from the refrigerator and let meat come to room temp. All meat should be placed in the smoker at room temp. Make sure smoker is up to temp. 170 degrees, put meat in smoker for 3 hrs, fat side up. After three hours of smoking, cover tri tip with foil to keep moisture in. Smoke another two hours. Med is 145 internal temp of the meat. Remove trip tip at 135 degrees and let rest. While resting internal temp should come up to 145. When it comes to trim tip smoking past med will give you dry meat. Do not over smoke.