I've been eyeing Tri-TIp at Costco for some time now. I finally caved in and gave it a try on my WSM. Put the Tri-Tip in a marinade of:
Lemon/Lime Soda with cane sugar
Fresh Ground pepper
Was hoping to marinate it for 24 hours then my wife reminded me of dinner plans we had the next nigth and I had to go to plan B. It only got to marinate it for about 4 hours but it still worked out.
Got the smoker going with some Hickory chunks. Cooked the tri tip at about 275 for about 45 minutes till the meat temp was 129. Then Seared it directly over the hot coals on both sides. Pulled it off the smoker and let it rest for 20 minutes. Sliced it thin against the grain on a diagonal bias.
Turned out amazing!
I served it with a great Horseradish Cream sauce from Alton Brown. Made some awesome steak sandwiches.http://www.foodnetwork.com/recipes/alton-brown/horseradish-cream-sauce-recipe/index.html