Assume the road is banked at angle θ above the horizontal.
Fc = mv2/r
N = normal force exerted by surface of road on car
N sinθ = component of normal force in the radial direction. This is the same as Fc.
N cosθ = component of normal force in vertical direction. This must balance the weight of the car.
N cosθ = mg ⇒
N = mg/cosθ
mv2/r = N sinθ = (mg/cosθ)sinθ = mg tanθ
v2/r = g tanθ
θ = arctan[v2/(rg)]
v2/(rg) = 162/[84(9.8)] ≅ 0.311
θ = arctan(0.311) ≅ 17.3º