Here is my 17.5 setup from WCICS Round 2 in Edmonton. The car was pretty easy to drive and had great corner speed, easily walking away in the infield.
The mod car was similar, but I struggled a bit to get the back end planted in a fast chicane. There changes from stock to mod were:
Serpent white rear spring
Serpent grey front spring
40wt front oil
3.5 rear suspension bracket