Seeing that I do much racing on asphalt I was looking for some foam donuts would do the job. I found some ENNETI 1-12 foam donuts with shore 25 for the rear and 42 shore for the front which you can order from the following shop DMModel . The first set of tires I added some corally "JACK THE GRIPPER" additive. The result was very interesting as I had much more grip when using the corally foams tires that I use. The track that I use is very dusty and I noticed that using the additive the dust would make the tire very slippery after some minutes. I then tried the second set without any additive and the result was excellent. I had grip for 8 minutes and to be honest I had to much grip as the front would push in the corners. I had to place a harder spring in the front and increase the tension on the center spring. After these changes the car was on rails. After 6 runs the tires in the rear where about 1 mm less in diameter when I started and the front about 2 mm. The car that I am using is a corally SP12M.

I know that Enneti makes these tires only on request so you won't find them very easily. As I said above DMModel has them for a very reasonable price.