I flew over two speed bumps today and the fan hit the shroud, broke two blades off the fan so I spent about 20 minutes pulling the shroud off in little pieces and had to drive to work with an unbalanced fan. While at work I used a hacksaw to take off the opposing two blades and balance was restored. Now I have to see if a motor mount broke loose and caused the fan to hit the shroud. Luckily the Koyo didn't get damaged, After it cools down I'll install my old NA fan blade back on and have one less car part for my wife to complain about laying around.