Anyone with GF210 might know my answer...

http://www.tanabe-usa.com/gf210.asp?id=3

Do you guys know if tanabe's spring is progressive or Linear?

 

Yep, it's in the Suspension 101 thread.

https://my350z.com/forum/8293527-post13.html

 

Dude, i say we just close entire Suspension section and just leave Jason's thread...One could find out how the African Crested Porcupines mate from reading that thread...

 

Progressive and they are NOT 20%-30% stiffer then oem

Tanabe GF210 Series 350Z progressive springs 1”/1.2”
Spring rates in LBS 336/375 (only peak rates are published, softer initial progressive rates unknown)

Vs 03-04 oem +7%/10+

Vs 04.5+ oem +7%/-12%

Progressive springs are not only defined by having a grouping of tightly spaced coils that bind to change rate. Springs can be wound with a coil diameter that changes (Kw Variant 1, 2 & 3 coilover front springs). I have never seen a spring that changes wire diameter, but that is another way a spring can be progressive.

 

Tanabe! sry.