In a small bowl, combine butter, lime zest and juice, chili powder, garlic and salt and pepper and set aside.
Carefully peel back husk from the ear, without detaching from the bottom, remove silk from corn, fold the husk back around the ears and soak in water for 30 to 45 minutes. Make sure to weigh down the ears so that they are fully submerged.
Preheat a grill to medium, indirect heat. Remove ears from water, drain, open husk, dry ears with paper towel and spread butter mixture evenly on corn. Fold husk back over corn and grill, turning often, for 35 minutes (change heat to medium-high for the last ten minutes of grilling). Serve immediately.