Here is the setup Kiyo gave me at TITC, the TRF team were all using slight variations on this setup. The track was medium size (50m straight), fast and super high grip - people were traction rolling on asphalt! Its not a big nitro track like it appears in videos, the infield is tighter than it looks.
We started out using 0.5mm shims in the wheels but this pushed a little in the tighter corners so I went to 1mm the same as Jilles when the grip came up and for me that was better.
http://db.tt/nlCvYTLH