European Stage 1 springs, to cut of not to cut...

[ironhelix]

I have a set of Euro Springs I bought 15 years ago, and everything I've read says I need to cut them. However, looking at the specs for the standard and euro springs, I shouldn't have to. Here are the specs I have for both:

I could not get the table to format properly. I hope you can still make sense of it.

European Spring Stock (from 72 manual}

RH Front 54010-E4107 54010-E4104

Spring constant: 100.795lb/in 83.000lb/in

Inside diameter: 3.937in 3.937in

Free length: 13.031in 14.700in

installed height/load 7/604in/lb 8/604in/lb

Loaded length: 7.008in 8.000in

Typical loading: 604.067lb 604.000lb

Wire diameter 0.442in 0.417in

Active turns of coil 8.500coils 8.500coils

Coil turns 9.500coils 10.000coils

LH Front 54010-E4106: 54010-E4102

Spring constant: 100.795lb/in 83.000lb/in

Inside diameter: 3.937 in 3.937 in

Free length: 13.031in 15.200in

installed height/load 7/560 in/lb 8/562 in/lb

Loaded length: 7.008 in 8.000 in

Typical loading: 559.974lb 562.000lb

Wire diameter 0.442 in 0.417 in

Active turns of coil 8.500 coils 8.500 coils

Coil turns 9.500 coils 10.000coils

Rear 55020-E4201: 55020-E4102

Spring constant: 115.915lb/in 103.600lb/in

Inside diameter: 3.937 in 3.937 in

Free length: 14.016in 14.500in

installed height/load 8.86/653 8.4/635in/lb

Loaded length: 8.858 in/lb 8.400 in

Typical loading: 652.568in 635.000lb

Wire diameter 0.460 in 0.449 in

Active turns of coil 8.500 coils 8.500coils

Coil turns 9.750 coils 10.650coils

Based on this chart, The euro front springs should be 1" shorter when loaded, the rear should be ~0.5" longer. Perch heights should have nothing to do with the loaded length of the springs. The load numbers are close for both spring sets, especially the front. What am I missing here?

Edited May 9, 2012 by ironhelix

[Carl Beck]

Perch heights should have nothing to do with the loaded length of the springs.

Move the lower spring perch up or down the strut about 1 inche - and all 7" inches of "Installed Height" goes up or down with it. That is because the upper spring seat is not fixed... Perch height directly effects the ride height of the car because the upper spring seat is fixed to the body.

Also - a stiffer spring will compress less in lenght with the same load as a softer spring.. so I wouldn't put too much faith in looking at the "installed lenght" given.

FWIW,

Carl B.

[ironhelix]

Okay, that makes sense. I just hate to cut springs by trial and error.

I wish there was a less stiff spring set out there than the Eibach's I presently have. I suspect Eibach has changed the design since I purchased mine back in the day. Each spring has a stack of about 6 coils that are nearly touching. I suspect they would be better described as a dual rate spring.

The Mulholland springs and struts I had were a great setup. Some one should offered a design like them.

[Arne]

Okay, that makes sense. I just hate to cut springs by trial and error.

I totally understand. I cut mine in little snippets - took me 3 cuts over several weeks to get it down to stock height. I was terribly afraid of cutting too much.

[Carl Beck]

I wish there was a less stiff spring set out there than the Eibach's I presently have. I suspect Eibach has changed the design since I purchased mine back in the day. Each spring has a stack of about 6 coils that are nearly touching. I suspect they would be better described as a dual rate spring.

From my notes of an earlier discussion = Ken P. reported Feb 06:

Eibach: Front 69-183 (prog) / Rear 86-212(prog) with a 1" drop.

FWIW,

Carl B.

[Travel'n Man]

Everytime you lift the rear wheels you always have to double check the spring perch due to it not seating back correctly. Before you cut anything or measure anything make sure they are seated......if not you could end up with a "surprise" you were not counting on.

[ironhelix]

Thanks for the advice. I'll be sure everything is aligned, top and bottom.

[Arne]

The cut Euro SS1 springs are still plenty long enough to stay tight in the spring perches. Unlike some lowering springs, they will not need to be re-positioned after jacking up the car.