Spring Rates Q's?

[240 2NR]

Now I'm wishing I paid a little more attention in high school physics.  

What I'm wondering, (or can't remember) is if spring rates are linear.  More specifically, will a 400 lb/in spring be four times stiffer than a 100 lb/in (this is roughly the rate for the stock front S-13 springs correct?) spring?  

What other numbers are important to look at for a street/auto-x setup.  I'm starting to look a getting the Tein HA coilovers and though I don't plan to install them till the spring, it sounds like Modacar can take their time with shipping so I may need to order early if I go with that setup.

[uuninja]

The ratio is how much weight it takes to compress the spring one inch. Of course there are progressive springs like most eibach which offer more resistance the more the spring is compressed.

[DSC]

Are tien's progressive?  Progressive is better itsn't it?

[uuninja]

No I am sure Teins are not.
Progressive springs are really for street use. They allow the car to sit lower and provide greater comfort over small bumps and pot holes. But linear springs are better for performance.

[240 2NR]

No I believe the Tein's are not progressive and are roughly 400 lb/in in the front.

I would think performance is better on non progressive springs since they compress in a linear fashion (predictable), and are stiff to begin with.  Progressive spings are soft on the street, but that traslates into lean on corners until they reach the stiff part of their travel.

I'm still curious is 400lb/in is four times stiffer than 100lb/in?  

[uuninja]

Well it takes 4x as much weight to move the spring one inch so that would fall under my interpretation of 4x as stiff.