I would look into getting a billy-goat type blower to clean track. It is a walk behind high speed blower made for cleaning asphalt prior to seal-coating. Painting Pete up at PNP hobbies in Palm Bay uses this type blower. Alex mentioned after he ran there that it was loose. I also looked at the track about a month ago the ac or liquid asphalt is wearing away and the rock is exposed more now which causes top layer to ravel. Thats why it starts looking white ,not black. Many coats of sugar help, but a light coat of sealer might be needed in the future. Sealer can also reduce traction, but sand should be added to sealer ,which helps. Hope this helps, good luck!!!!