[wallot]

70WT oil for racing? thats crazy unless on very smooth track.

try this: as thin oil as possible (300cts front 350cts rear) with hardest springs as possible. why? the goal is to have wheels on ground not in the air

soft oil helps shocks react faster and hard springs return shocks faster. and progressive shock position, in case of revo as progressive rockers as possible
excellent for broken tracks.

for smooth tracks the other way around. thick oil with very soft springs.
for many people it sounds very strange but dont judge it unless you try it.