If you use the dirt that is there, it will take work to maintain the surface if 1/8 scale use it. If the dirt is loose, use step pins. We had a track in our area but was closed down due to poor maintance. It will take alot of watering to keep the dust down. What area are you planning to set up this track? Is the soil sandy or does it turn to hard packed when it is dry? Have somebody with a r/c test the dirt to see if it breaks up.