"4-Way suspension" work alike?

[PhillipM]

Exactly as above, set your torsion bars to come in progressively in stages. Hell, at one point on the racer we had twin springs on the coilover changing rates halfway through the travel and torsion bars coming in either side of it, so 4 different progressive rates. Gives you the exact same effect.

Probably better in fact as you can make sure the rate switch isn't at the ride height which can end up with really strange handling quirks with different loaded weights for passengers/luggage, etc.
Either way, if it's something that's fitted as an assister as well as the main spring, what it's doing is nothing fancy, a good marketing gimmick perhaps, it's just giving you two spring rates, one softer and one stiffer than standard. A dual spring setup on a coilover without the torsion bars will do that, staggering the preload on the torsion bars will do it, a soft spring on a coilover with the torsion bars wound back to come in halfway through the travel will do it, long urethane foam bumpstops on a stock damper, etc, etc. Nothing is 'pulling' on the spring per se, just the main vehicle spring is pushing against it.

[Piledriver]

... The only way they could exert no force at all would be for it to be fitted as a secondary spring system whilst keeping torsion bars/whatever the vehicle normally had...

You had it there for a moment, and no, that's NOT REMOTELY the same as a simple progressive rate spring if you think about it for even a second.

I must be using the wrong words or something...

OK, missed a post, I think you have it now with your 2 spring + 2 torsion bar setup, but this is probably ~as effecive and a WHOLE lot simpler to get the ~same effect,
...and it's also not the same as large foam bumpstops.

[PhillipM]

Of course it is, a foam bumpstop will give you two spring rates, just as this does (albeit they tend toward rising rate at the end of their travel, but so do most cheap springs).
A progressive spring can be wound to give you either two distinct rates or a fully progressive system from one rate to the other, personal preference, same effect.

Far cheaper to just do it with a normal spring on the coilover, or a bumpstop, or just load one torsion bar up more than the other if you have to retain the torsion bars anyway?

[helowrench]

Alrighty then, i will bite.
Standard torsion bar carrying a standard weight car.
Normal coil over helper spring is added. Set at 0 additional spring rate when car is at rest.
(most helper springs are not infinitely adjustable like this.)

This is the set up that you are describing. I can see how this adds spring rate for the compressed wheel, but cannot see how this reduces spring rate for the extended wheel.

[PhillipM]

If you have adjustable torsion bars, wind the preload off on a set. Or stick a set/sets in with less leaves.
Or remove one set if neither are available, so long as you can hold the arm on.

Or just leave it as it as, given the first portion of the travel will be similar to stock ride anyway, they'll all work in a similar fashion, it's just playing until you're happy with the spring rates, I was originally under the impression it was the main spring system from the description, hence the confusion, but obviously as a secondary system it's no different to achieving it any other way of splitting rates.

[Piledriver]

Alrighty then, i will bite.
Standard torsion bar carrying a standard weight car.
Normal coil over helper spring is added. Set at 0 additional spring rate when car is at rest.
(most helper springs are not infinitely adjustable like this.)

This is the set up that you are describing. I can see how this adds spring rate for the compressed wheel, but cannot see how this reduces spring rate for the extended wheel.

The springs are attached at both ends, at rest. It cannot do otherwise, as it counters the std spring extension force, effective rate reduction on extension, increase on compression.

If you build suspension stuff, you can probably make up a set to try yourself ~easily and see how well they do or don't work.
I'm not selling anything--- I'm buying.

Oh, wait, replied to Helo... Dude, just make some, the setup on a 914 will be ~trivial, but full custom in any case.
The compression and extension rates may differ somewhat, but so long as the sides match, it's OK.

[helowrench]

Are you kidding? The teener is getting air ride and 26"s.
scrapin the ground and bouncing.........

[Piledriver]

Are you kidding? The teener is getting air ride and 26"s.
scrapin the ground and bouncing.........

[Piledriver]

I'm still waiting for the second unit to show, but verified the springs/collars will fit the Monroe-Matics i have installed currently.
(I strongly suspect these Trailmasters are custom label Monroes due to how they are made/labeled)

The setup at the top of the shock is a tiny bit different than I recall, probably as these shocks are genuine 4-Way branded made to purpose... the retrofit setup I used ages ago had a little slotted cast aluminum collar that wedged between the cut off dust shield and the upper shock eye, these clamp around a slightly custom upper shock dust shield bit ~3/8" high... but spinning up a slotted collar or even hacking off the custom collars and welding are doable.

I just need to wait for the second one to arrive to make absolutely certain the springs and hardware are in fact twins separated at birth before i can give a yeeeha and put them on. (will go on the back as I lack a rear swaybar and it pushes a touch anyway, plus it will allow hauling more junk for the One That Must be Obeyed, NOW. )

[FJCamper]

Hi Piledriver,

I do remember the 4-Ways, and have been reading this subject with some interest.

I think the people who can't believe the 4-Ways work don't really understand how the spring attachments are different from say, a coil-over or suspension spring.

A coil-over spring is compressed, always applying force up and down against its stops.

A 4-Way applies zero force until you try to compress it or extend it.

FJC

[Soul]

While surfing that other site I ran across these Treuhaft load control springs. Are these closer to what you remember?

-Fit most front and rear shocks
-eliminates front end sag
-restores camber after installing wide wheels
-made from oil tempered spring steel
-no special tools required to install

[Piledriver]

I think those Treuhaft units are just std "helper springs", and only provide lift, but if the threaded spring capture units could be put on both ends and they could be secured to the top and bottom of the shock, they could work the same, the springs are ~bog std units AFAICT.

The 4 way springs attach/lock at the top and bottom, typically in an unloaded condition.

You can apply preload if desired, I used them (ages ago) pulling the rear down ~1" for a softer initial rate at launch, seemed to soften the rear end for better bite, but still ~zero roll, at least in the amusement park of my mind.

EDIT: second one won't be here until Friday, I'll post detailed pics to show exactly how they are built.

I've been thinking about it: On a SA car there would utterly transform the handling and safety in a matter of 20 minutes, assuming the tire/wheel combo was up to it.
They effectively would replace camber compensators etc, only better. (might still want some limit straps)

Trailmaster was still flogging these for Jeeps and motor homes in 2009, so they haven't been off the market in the USA all THAT long. ToughDog (in Oz) still makes them but has apparently given up pushing them for normal apps, as no one gets it unless you have used them already.

[Piledriver]

Second unit showed, spring/lock assys are twins separated at birth.

Will provide pics etc this weekend, have to crash.

[Piledriver]

I hope the picture makes it obvious how they attach/work:
These were on different length shocks for different apps, but the springs/mounts were identical. They upper and lower aluminum bits split and clamp on Monroe shocks just fine, although the upper mount may need some work, as the retrofit units i had back in the day came with a slide-on adapter to attach to std shocks with the dust shield removed, so I'll get to do some cutting/welding. May need to cut springs down for T3 app, too long.

[Piledriver]

...and it turns out Monroe-matics dust covers are ~just the right OD for the upper clamp bit with careful work with the cut off, and are actually a tad thicker than the 4 way custom units, although i may add a touch of weld for insurance.

Measured unloaded/suspension at rest shock length and orientation (I cut off most of the dust cover and used a sharpie on the shaft)

Cut 3 turns off the spring, could probably have gotten by with two

Complete unit, length and orientation set, ready to go in.
(These Monroes are low pressure double tube gas shocks)

BTW---The rear end is now ~pothole proof, now hunting another set for the front..
Turns in ~dead flat, but the front end now feels like mush.
Perversely, seems to ride better somehow.
I'm wondering how to calculate how much effective dampening the dual/counter springs add, the T3 front shocks are even softer and identical dimensionally.
Based on my bathroom scale and a ruler, they seem to be ~150 lb/inch springs.