I've drove my friends Z with some Tanabe spring and they feel really great so i

was checking out information about springs and some people were asking me

if these spring were linear or progressive. What does that mean?

But any ways i saw some pictures of Zs dropped on Tanabe GF210 and it looks

really great for the cost

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


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

 

Linear = soft

Progressive = stiff

Thats all u get....search.

 

Wrong lady.

Linear springs keep their same level of lb/in through their whole compression range.

Progressive are usually pretty soft till they get to a certain point(lets say half.) At that point they become stiff like linear springs.

Linear usually feel stiffer on the street but are better at the track because they are predictable.

Progressive are usually more compliant on the street while sometimes offering better handling on the street, but many people dont like them for tracking because of their unpredictability.

 

Thats all u get

vv

 

As mentioned,.....

A linear spring: From one extream to the other, this spring gives out the same stiffness per inch at all times, from no weight on a wheel to full compression as in deep into the bumpstop. Take a corner and at each end of the car, the otherside is on the same page, no differance in spring stiffness at all points in wheel travel.

A progressive spring: From one extream to the other, this spring does NOT give out the same stiffness per inch of travel at all times, from no weight on a wheel to full compression as in deep into the bumpstop. Take a corner and at each end of the car, the otherside may be on the softer initial spring rate that may be as much as 50% less and not on the same page, at a certain point in wheel travel, differances in spring stiffness will occur, huge question is, at what point?

I've noticed that buyers are generally in one of three groups.

1. Don't care to know what the differance is, I buy on looks and how many owners shout out how great the spring is.

2. Know the differance, but I don't plan on tracking the car, looks is more important, besides is doesn't matter,.....does it?

3. Know the differance and a progressive spring will never be something I put on a sports car which I just might want to enjoy, track or no track.


Here is a picture of the rear spring and upper mount from a Bilstein Pss9 coilover. Notice the tightly grouped coils at the top, that is one way a spring is progressive. This spring has a rate of 240-420 (shows initial and final rates)


Here is a picture of how I killed the progressive spring above by making a simply 6061 adaptor seat and installed a linear spring in it's place, rate 450lbs. In back to back drives, no comfort was lost and I got much better, more predictable handling.


Here is a picture of the other way a spring can be progressive. From top to bottom this spring slightly differ's in how wide it's coils are. This make it progressive and since it can never bind, no sudden rate change occurs. And because the differance in coil diameters is slignt top to bottom the differance between initial and final rates is also slight.



^Tanabe GF210 are a softer spring then the Eibach Pro-Kit. His comments aren't exclusive to a tracked car, no one here bought a sports car and won't ever push it?

 

ahhh thanks mate that was very informative *cheers*