Heres how I do them.
1. Prepared meat first with a little fresh ground sea salt, then fresh ground pepper, then some whiskey steak seasoning and finally some rosemary flakes. I wrap in stretch wrap and let this rest in the fridge overnight.
2. I mound the lump in the front of the kamado and you can see that the meat was in the back for indirect cooking.
3. I do it 20 minutes (40 total) per side. (I probably didnít need to flip it)
4. The internal temperature is the important part and 40 minutes (give or take a few) on my setup gives me an IT of 115. Your setup may yield a different time so just monitor the IT and youíre good. You could also smoke it longer at a lower temp or shorter at a higher temp so long as you achieve 115 IT.
5. Remove and tent with foil.
6. Now open up your vents to get your kamado / grill to around 550 to 600 degrees. Once it's there sear the Tri Tip for approx 5 minutes per side and you'll be at a IT of approx. 130 to 135 which is IMHO the perfect temp for Tri-Tip. It doesn't do well if cooked past medium and is better as medium rare.
Hope this helps.
Here's a link of one of my cooks.