Spring Rates
 

Is there a way to tell what the spring rates are on lowering springs/coilovers. Most manufacturers don't mention it on their site. I know JIC can have custom spring rates or even ones that you can change the spring rate yourself. Thanks.

you can have them tested. Problem is, I dont know where. Many co's dont list spring rates because the average person who Purchases Sport/Lowering springs wouldn't know what do do with the Information. The more Reputible Racing suspension companys like H&R, Tein, Eibac, and Neuspeed to name a couple, would be more then happy to tell you the their spring rates, all you have to do is call them and ask.

Tein S Tech spring rate:

front/back:
2.8/5.2

We under stand LBS/In her in America. Metric tends to confuse us.
:hgrin:

157lbs/in front and 291lbs/in on the back. not very stiff at all.

The SS springs are

336lbs/in front and 448 lbs/in back. More then twice as stiff on the front.

and its also hard to say with progressive springs since it varies... it gets stiffer n stiffer as it gets compressed more..

so, the tein rate is linear or progressive?? & is the ss really doubling the stiffness??

Coilovers are linear racing springs, lowering springs are typically progressive.

when Racing is involved Linear springs are better to have then Progressive ones. on the street, Progressive will give you a better ride when your just cruzin but still retain some level of performance when pushed.

That is why companies like eibach, progress, neuspeed, etc say it is x-x% stiffer than stock. They vary when they are compressed/extended.

Conversion Chart. Should be useful for some people.


0 Kg/mm 0 Lb/In
1 Kg/mm 56 Lb/In
2 Kg/mm 111.9 Lb/In
3 Kg/mm 167.9 Lb/In
4 Kg/mm 223.8 Lb/In
5 Kg/mm 279.8 Lb/In
6 Kg/mm 335.7 Lb/In
7 Kg/mm 391.7 Lb/In
8 Kg/mm 447.6 Lb/In
9 Kg/mm 503.6 Lb/In
10 Kg/mm 559.5 Lb/In
11 Kg/mm 615.4 Lb/In
12 Kg/mm 671.4 Lb/In
13 Kg/mm 727.4 Lb/In
14 Kg/mm 783.4 Lb/In
15 Kg/mm 839.2 Lb/In
16 Kg/mm 895.2 Lb/In
17 Kg/mm 951.2 Lb/In
18 Kg/mm 1007.1 Lb/In
19 Kg/mm 1063.2 Lb/In
20 Kg/mm 1119 Lb/In

Boilermaker1 gave this awhile ago.

1 lb/in=.017854 kg/mm

One of my friends estimated the rate of his springs by measuing the Diamiter of the coil, Simmilar to how you can calculate the rate of an anti-roll bar by knowing its thickness.

I'll ask him about it.

Found a Coil spring rate Calculator...

Another (More Informative)

neuspeed race springs are 285/400. since they are performance minded springs, are they still progressive like the sports springs?

You can tell its a progressive spring if it has dead coils on it. Whereas a linear spring coils are evenly spaced for the most part.

most true coilovers are linear springs, most aftermarket springs are progressive. Sleeves are just aftermarket springs on an adjuster so they are usually progressive too. But flotsamm is right.