Preheat oven to 180ºC . Season wings with salt, pepper and garlic powder. PLace in a shallow baking dish and bake for 15 minutes. in a small saucepan, combine ketchup, vinegar, sugar and water. Heat, stirring until well blended. Brush sauce over wings and continue baking for 20 to 30 minutes, or until wings are tender. Remove from oven, and serve.