I'm no expert on the Tesla turbine so take any advice with that in mind. However, my understanding of the operating principles are that the plates have to be close enough together that the surface friction comes into play. In other words, the volume of air entering compared to the area available for exit has to present enough resistance (friction) to pull the disks as the air moves toward the center exit. The first thought would be reducing the 1/8" between disks. Otherwise you have to pump a much higher volume in to develop the inlet pressure that makes it viable.
"Opportunity is missed by most people because it is dressed in overalls and looks like work." Thomas Edison