Springs Springs Springs

[KamiSpeed]

So an interesting subject came up about what the OEM spring rate is and how aftermarket springs compare.... so after a little bit of research and asking around this is what I got:

OEM:

Front: 2.3 kg/mm - Rear: 3.4 kg/mm

B&G:

Front: N/A - Rear: N/A
Front: ~1.2 inch drop - Rear: ~1.2 inch drop
S2 Sports Springs

Eibach:

Front: 2.4~2.75 kg/mm - Rear: 1.7~4.0 kg/mm (Progressive)
Front: 1.0 inch drop - Rear: 1.0 inch drop
Eibach Pro-Kit

Espelir:

Front: 2.4 kg/mm - Rear: 3.1 kg/mm
Front: 1.2 inch drop - Rear: 1.4 inch drop
Active Super Down Springs

H&R:

Front: N/A - Rear: N/A
Front: 1.3 inch drop - Rear: 1.3 inch drop
H&R Sports Springs

Kansai Service:

Front: 2.5 kg/mm - Rear: 3.9 kg/mm
Front: 1.0~1.2 inch drop - Rear: 0.8~1.0 inch drop
HKS Kansai Service Sports Springs

Swift:

Front: 3.0 kg/mm - Rear: 4.5 kg/mm
Front: 1.2 inch drop - Rear: 1.2 inch drop
Swift Sports Springs (by far the most detailed information about their design)

Tanabe:

Front: 2.2 kg/mm - Rear: 3.5 kg/mm
Front: 1.3 inch drop - Rear: 1.0 inch drop
NF210 Springs

Tein:

Front: 2.2 kg/mm - Rear: 4.0 kg/mm (Progressive but Tein gives one rate??)
Front: 0.8 inch drop - Rear: 0.9 inch drop
High Tech Springs

I saw somewhere else in the forum that the spring rates are 3.5 kg/mm and 3.0 kg/mm (front and rear respectively) so idk which one of us is right.

Regardless I think it's good info to look at. Leads me to believe that Swift and Kansai focuses on stiffening the rate more so than other companies thus improving performance. Espelir, Tein, and Tanabe stay pretty close to what seems to be my estimate of OEM, so they will give you the same comfort with drop. As for Eibach, idk what to think of their setup, its definitely an inbetween. Oh and H&R doesn't publish their rates so... idk haha.

Let me know if I should include some other springs.

[JCRZ]

B&G has springs too. HKS kansai service has a set too. That's about it I think.

[KamiSpeed]

Originally Posted by JCRZ

B&G has springs too. HKS kansai service has a set too. That's about it I think.

up, thanks

[Scotty001]

@ Kami - Hey, thanks for putting that together.. Great information for the Forum..

Good Stuff.

[716atHeart]

Thanks KamiSpeed!!

[KamiSpeed]

NP haha I was curious myself -_-

[northbridge]

stock specs you have are correct @ 2.3 and 3.4

thanks for this thread!

[franck2725]

this all sound very interesting but for someone who doesn't know much about it tell me,if i just want to improve the suspension what do i choose more or less than the oem,

this is what the trunck look like all week long,i would like to stiff up the suspension,so went i hit one of are numerus pot hole it reacte better that oem. what would you do???
thanks for the info

[TinTin]

Originally Posted by KamiSpeed

So an interesting subject came up about what the OEM spring rate is and how aftermarket springs compare.... so after a little bit of research and asking around this is what I got:

OEM:

Front: 2.3 kg/mm - Rear: 3.4 kg/mm

How did you get these numbers for stock? I thought they were both 3k all around.
its strange how the fronts are softer than the rears. Looks like my springs do have quite an upgrade over stock after all...

[northbridge]

^ KoalaYummies provided the stock spring information from a HyperRev book i believe (further detail is in the coilover comparo thread). The specs are listed there.