We already have watched this video. You better focus on 1.5 turn. Opening it further down only will mess the fuel average while performance will affect too. This video is explaining the balance of air and fuel so it is clear now that when you open it down till 2 or 2.5 turn, it only messes the fuel average while air remains same. If you want to keep your settings around 2 turns then open the duct and increase air intake first.