i went on the ground control web site and haven't found stiffer spring rate than 430lbs/in. i saw lot of people talking about 500* where did you found it??

 

When I placed my order I specified the rates I wanted.

 

^^^ did the same

 

bu where did you ordered it, i saw ground-control-store.com or something like that. do they sell custom rate???

 

I ordered mine from one of their authorized retailers. http://www.gruppe-s.com/

 

hey if u r intereseted i have a pair 500lb right now those r on the car but ill change the rates so if u want let me know

 

They carry pretty much any spring rate you could want.
http://www.ground-control-store.com/...ory.php/CA=213

 

my looking at the numbers on the springs how do you tell what the spring rate is?

Also if all of them are same spring rates is there a difference between front vs rear coils?

 

I believe it's length.diameter.rate, which is why they all have 250 in the middle (I linked directly to the 2.5" diameter spring page).

Rear sleeves are longer on Integras at least, not sure on other models, same perches though. Some cars use a longer spring on one end as well, but that isn't necessary (adjust spring perch to compensate for spring length).