Originally Posted by
metalnut
Harder springs / less body roll actually reduces grip. Unless the springs are so soft that the weight transfer can't actually follow through to the tires, but I'm doubting that's the case. If you want to reduce body roll I'd go for the sway bar kit first and start soft. If you're doing offroad, going too stiff on springs/bars will make for an unpleasant ride with no grip.
I agree with metalnut. For tarmac, increasing the spring rate will reduce grip in order to reduce body roll; it might introduce either some heavy understeer or oversteer. When talking suspension, there is no easy solution, itīs all about compromises. The setup that works for me is to have somewhat soft springs and stiff sway bars. Conceptually, sway bars are just springs positioned in a different location.
An example of a similar configuration: soft springs, stiff arbs is the Impreza STI. The 1998 Impreza STI version IV, for example, has:
Front:
-Spring Rate/Wheel Rate (lb/in) = 196/180
-ARB rate/Wheel Rate (lb/in) =400/268
Rear:
-Spring Rate/Wheel Rate (lb/in) = 174/135
-ARB rate/Wheel Rate (lb/in) =285/168