In general, shocks built for the Japanese market have too much compression damping for US roads and race tracks. Our Tarmac surfaces are much bumpier then the surfaces in Japan and the shocks needs more compliance in bump to let the tires grip well. Also, most car owners think a stiff ride means good handling so low and medium priced shocks are made with more compression damping the ideal for grip. Good shocks are generally $300 a corner and up in price. That's just the shock, not the spring, camber plate, etc.