going to buy gc coilover, but dont know about the spring rates...
i don't really like a ride that is stiff...
even OEM setup is a little to stiff for me i guess....
pls inform me, kg/mm what it means... the heavier kg the stiffer or softer????

 

Yes, higher is stiffer. These numbers are in lbs/in, which means it takes X number of pounds to compress the spring 1 inch. 1kg/mm = 55.88lb/in

Here is some data from other board posts to give you an idea of various options.

MY00-01 = 218/291
MY02-03 = 240/230
MY04-07 = 256/207
MY08-UP = 274/225
MY08 CR = 375/264
Tein S-Tech = 296/363 with a 1" Drop
Comptech = 220/280
KG/mm sport = 398/448
Neuspeed = 280/215 with a 1.25" Drop
Espelir Active Super Down = 314/392 with a .75"/1.2" Drop
Spoon Sports Progressive Springs = 263/383
Tanabe GF210 = 283/378
Backyard Special European R Springs = 262/335
Eibach Pro-Kit Springs = 263/343 with a 1" Drop
Bilstein PSS9 Coilovers = 345/285 with an adjustable drop

Spring rate only tells part of the story. Shock valving/damping goes a long way towads your impression of the stiffness of the suspension. I have the Bilstein pss9, and despite much high spring rates, it doesn't feel much different than stock over bumps in the road. On harsh areas - bridge joints, patched asphalt - sometimes it feels better than stock.

 

The standard Ground control spring rate should be 340/380. Which is 340 (pound / in) = 6.07170889 kg / mm

You can type this into google search and it will convert it for you.

"XXX lb/in to kg/mm" or the other way around.

 

I was looking at these too. you can order it from groundcontrol.com and tell them you want a comfortable ride and they will custom make u a set.

 

i have 425/400 ride nice, not too stiff at all

 

u say MY04-07 = 256/207 so that means the front is 256lbs/in and the back is 207lbs/in???
which means if i want it softer i should get below 256lbs/in front and below 207lbs/in for the rear???
or it means 256lbs/207in???
i am just going on oem shocks by the way is it possible to make the ride more comfy just by installing the ground control coilover only without changing the shocks???

 

that's front and rear

256lb to compress 1 inch in front

207 lb to compress 1 inch in the rear

spring and damper(and other suspension part) are design to work as a system, going low on springrate(and god forbid if you going to lower it too) might make a boat ride out of your car, which might or might not result of bottoming out of your damper


you are 6 foot tall = 183 cm, you are not taller or shorter, just the scale is different

kg/mm(or kg/cm) is just different scale to measure the samething(used by pretty much everyone else other than us), force applied vs compression(measure in distance).

metric vs good ole american type of deal

 

so what do you guys think of the most comfortable spring rate would be?

 

1lb/in then you need 700 inches of travel to not bottom out


lol, in all honesty, it depends on both damper and spring rates - a good damper might be able to run higher spring rates without feeling harsh. Bilsteins are a good example

 

I just ordered their full Coilover Kit for the S2000. I went with 550lbs/in all around. Hopefully it will be a good match to my non staggered set up 255/40 all around and the Sanner Bar I just ordered