What would be a good setup for this track?

it is "Outacontrol Raceway" on youtube and its the video that is 1:59 long

It is hard packed clay, has a groove and it develops a little bit of dust.

I running silver springs all the way around, stock link locations, stock wt oil, shocks are in on the tower and out on the arms and barcodes. I am able to turn some fast laps but it seems really inconsistent (could be me). The fast guys are like a half to a whole second faster a lap... Thanks!