Sorex 32RY (Yellow insert) are good on asphalt tracks, as long as they are not too cold.
If the track is below 10degC you might find Sorex 28RY are a better choice.
Hope that makes sense
Xray T4'16, T4'14 (Wet Car)
Xray X12 2016
wlrc.co.uk (West London Racing Centre)