What about Swift coilover springs ? Whats the inner diameter of the stock springs ?

these:

http://splparts.com/store/product-info.php?pid127.html

 

Actually slip machine unless you on sticky and really wide R comp tires.

 

^^^

at high speed....yes

 

those need the spl midlink to work

 

i'm not concerned about the rear as I can always just cut the spring mount, I'm wondering if a slightly shorter spring of the same stiffness (9kg would b about it IIRC) could be used on the stock FRONT damper.

 

The diameter of them does not allow those Swift springs to work without using the SPL midlink. Z rear springs are tapered, Swift race springs are constant diameter. That is why those are listed as 'coilover springs' because they are intended for use with coilover setups, where height is adjustable. They are not bolt in lowering springs ala Tein S Tech, Hotchkis, Tanabe GF210, etc etc. The SPL midlink out back satisfies that requirement, and would then require an appropriate shock to me mated to it. And no, they cannot be used up front either, unless again, it's on a coilover setup that uses those diameter/length springs