I got an 06 6mt g35 with sport tuned suspension. Just looking at the spring rates of coilovers vs. stock ( 314, 427), most are softer, or in the same ball park. I was gonna go the hks route, but apparently they dont make anymore(according to website and a few vendors i talked to) So i think im stuck with the KW v.2 with harder eibach ess springs.( zeals and bilstein pss9 are even softer). Maybey im complete off only looking at spring rate, but the body roll is the unacceptable aspect of the suspension( feels like the body is "lifting/floating" when going into turns( even gentle bends at 50+), very unsettling). Should i just scrap the coilovers and go crazy with sways, and Gt spec braces, struts, OR is there a solution im missing. Im at a loss just looking at the spring rates. Want a street setup that i can dawg and not feel like im gonna fly off the road and end up in a ball of flames.

edit: the tein flex and mono flex have higher spring rates but i hear the float is even worse. And i DO NOT want a serious drop, the undercarriage is hitting speed bump already

 

Try a stiffer anti-roll bar first, then move onto a spring/shock or coilover setup. I think the rest of the stuff you mentioned is more oriented for keeping suspension settings more consistent than anything else.

 

humm, i dont think your converting the spring rates correctly. the zeal function xs "stock" rates are 10kg/mm and 8kg/mm = about 560lb and 450lb (and you have to remember the zeal is a trrue coil rear) again, just check you conversions, or even stock rates are 5.6f and 7.6kg/mm r.

 

Sways FTW , i dont know why they are so dam soft from the factory