Set up a grill with one chimneys worth of charcoal off to the side.
Season tri-tip with oil, salt, pepper and garlic powder.
Add some wood chips to the charcoal.
Once wood is smoking, move wood chips to far side of grill and place tri-tip above the smoking chips. Turn tri-tip every 10 minutes or so.
Mix potatoes with 1 tsp olive oil, 1 tsp kosher salt, and 1 tsp black pepper
Place potatoes on hot side of grill and grill for 10-15 minutes, flipping every 2-3 minutes, or until potatoes are softened.
Remove potatoes from grill, add some more wood chips to charcoal and cover grill with vents open.
Chop potatoes and mix with remaining ingredients.
Once tri-tip reaches rare (115 f), sear over hot charcoal for 1-2 minutes per side.
Let tri-tip rest for 10-15 minutes before slicing against the grain.