Mike, I have never had good luck cooking chichen directly over fire on the grill. The fat is just too flammable. Try putting a drip pan (put some water in it or the fat will burn in the pan) under the grates either on a cool side of the grill or low heat side. Then put the wings (with out a rack like mine) on the grill and run the grill to 350-450 degrees skin side up. No need to turn them other than to rotate them away from the hot side. They will crisp nicely (if you need to protect them a little, I build a shield with heavy Aluminum foil doubled over a few times and make a "wall" between the hot side of the grill and the chicken. (sometimes the "indirect" heat is still too much for the flammable skin and it will burn).My grill gets to maybe 450-500 most days. It's a cheapie. When I cook wings on it, I do 30-40 minutes on each side on the grates, no rack, at medium to low flame so it doesn't flare up. I watch them the whole time and move around 1-2 times per side before turning. When done they're good tasting, but wither burned or not crispy. I use olive oil as binder to hold the rub. Similar thing happens if I smoke them first in Smoker for an hour then finish on Grill.