I've got a Brinkmann vertical smoker (Trailmaster Limited Edition) and will attempt to smoke some tri-tip roast today. My first time. I've got four tri-tips totaling maybe 12 pounds. The recipes I'm pulling up all seem to call for about 2 hours of cook time for a single 2-3 pound tri-tip roast. My question is, should I add additional cook time due to the larger amount of meat I'm smoking? How long should I plan on cooking the meat? And I may as well ask what the optimum cooking temperature should be in this case. Thanks for any help!