goldhunter_2, you really can not compare the Q with the S and I apologize for that. sometimes it gets difficult to understand our prop nomenclature, these 2 blades are meant to work on totally different applications in most cases. Q blades are designed as left hand rotation only and work better on direct drive applications , it is a shorter prop that ranges from 67" to77" depending on the hub and is also not as wide (10.5").The S blades or known as SUPERWIDES apply to automotive engines with reduction units that apply 2200 max. prop rpm. They are power hogs so you need alot of power or a higher ratio of reduction to achieve an efficient setup, even though larger in dia. and wider (15"), they will produce lower noise because of the range of rpm that it works best at. A majority of the time prop rpm is going to dictate noise levels to a certain extent, other things like boat setup and engine noise will also contribute to a quiet running boat. I suppose whichever blade design most fits your application should be the one to choose, but they both do very well for there specific applications. The main things to look at when trying to figure out if the S blade will work, is 1 engine power and 2 reduction unit. Also the S is available as left or right hand rotation, so belt or gear drives are ok for this blade design . I hope I hit the key points let me know.
