Xray T2009 Setup for low traction polished wood floor?

[lucas-b4-b44]

Anyone got a good setup for Xray T2009:

- polished wood floors low traction
- indoor track small mixed and leaning toward technical
- using control tyres: 20mm schumacher yellow mini pins on 20mm wheels
- shock spring seem too loose when lowering for a 5mm ride height, can I just change shock position?
- should the diff be looser? When I hold one wheel and the spur should the opposite turn or be very hard to turn?
- I've got a 24 pinion on an 84 spur for a 13.5 LRP eraser giving about 5:95. LRP recommend 6:00
- Oh and I'm running ball diffs front and back.
- Setup for LRP SXX TC Spec, my settings: 1,4,1,1.
- back end fish tails on corner exit too.... (is this called oversteer?)

any thoughts and advice?