could someone explain the difference b/w progressive & linear rate springs?

[kidsdoc]

these terms have been coming up on searches although they're really not explained, i think the progressive become more stiff when you have increased body roll, etc. but are supposed to be more "soft" in daily driving whereas the linear springs are "always" stiff, is this correct?

also, of the popular aftermarket tuners (eibach, H&R, UUC, ACS, Racing Dynamics, any others i may have left out) which are progressive & which are linear? (on an e46 330i)

hopefully, this'll be my last post & question before deciding on which springs to go w/

[Joey325i]

all those comapnies mentioned will use a progressive spring in the rear because thats what it asks for on a BMW, so they match
the OEM spring, but when you jump into coilovers they all use linear springs which is stiffer.

[teuton]

Progressive rate springs increase their resistance to compression as the spring compresses. Linear rate springs have uniform resistance throughout.

Pete

[kidsdoc]

thanks, all; do you know what the following springs are: Eibach, UUC, H&R, ACS, RDSports, linear or progressive?

[Vitolo]

IIRC Eibachs are progressive and H&R are linear. There is a good chance I could be wrong, and I dont know about the rest.

[SG_M3]

Eibach uses some linear springs in different kits. All h&r are progressive.

The only real way to get linear springs is to go to a coilover kit, that way you can use any 2.5" or 60mm linear springs.

[SeCreTaZnBoY]

i know the prokit by eibach is progressive.
the h&r spring i think is linear...because the spring design is different. i dont konw if u have to have coilovers to be linear. my friend has h&r springs while i have the eibach...the h&r will roll less...but are the same stiff wise.

one more time.
progressive means the spring rate will increase as more force is aplied while the same amoutn of spring rate is present through the compression of a linear spring.

[SG_M3]

Originally posted by SeCreTaZnBoY
i know the prokit by eibach is progressive.
the h&r spring i think is linear...because the spring design is different. i dont konw if u have to have coilovers to be linear. my friend has h&r springs while i have the eibach...the h&r will roll less...but are the same stiff wise.

H&R are not linear, i can tell you that for a fact.

Eibach pro kit for the e36 m3 uses linear rear springs.

[bignate]

ok, so what are the pros/cons of each?


nate

[kidsdoc]

i guess the best thing to do is probably contact the manufacturers directly as it seems there is contradictory info?