According to Ivan at DeWALT Chat, DeWALT recommends using the DWA181440 to rip new, untreated 2x4s and the DW7118PT to cross-cut them. However, when I told Ivan that my table saw can run anywhere between 3,500 and 8,000 RPM and asked him what speeds does DeWALT recommend (for ripping and cross-cutting untreated 2x4s with my two new saw blades), he replied, "There is no exact chart for this, the torque of the saw, material, how worn is the blade, all those variables are combined together by the operator expertise." 

Can someone suggest a good starting point for ripping and cutting 2x4s with the DWA181440 and the DW7118PT, respectively?

Thanks!

Joe