"4-Way suspension" work alike?

[PhillipM]

4. One softer spring can dampen another stronger spring -- it is often done on the mechanical linkage for governors on small engines, for example, to provide smooth throttle control without surging/oscillation... It is NOT just "changing the base spring rate" that you seem to insist is the case.

Damp, not dampen. Two different things, since you like definitions.
Here's another one from a more reputable source than some random blokes badly worded Wiki entry, OED:

• technical a reduction in the amplitude of an oscillation as a result of energy being drained from the system to overcome frictional or other resistive forces.

Still not happy? Have another:

a method of bringing about a reduction in oscillatory peaks in an electric current or voltage using an energy-absorbing or resistance circuit

Notice one thing in common? Both are through controlled energy removal. Exactly as per my earlier definition.


I've seen a lot of twin sprung governors, and without exception they've all had the secondary spring for fine idle control (springs, outside a perfect world, are non-linear for small displacements at the start and end of their travel, hence the smaller spring used for control when the main spring is lightly loaded, it's for much more accurate control of the spring force)
I'd like to see this example of yours where it's used for damping, as I've never seen that, they've all been for the above reason, would you have a picture?

[KentT]

No, I'm done parsing words with you...

But, the second spring on governors for small engines is not at all as you describe. They're to stabilize the RPM at high-or-full-throttle application -- i.e. under working loads. The governor doesn't even come into play at idle -- only the throttle control cable or linkage. The governor controls maintain the RPM set by the throttle linkage under changing engine load... and the secondary spring reduces the oscillations in the primary spring (which is responding to airflow off the flywheel fan, in air-cooled engines) and helps stabilize RPM fluctuations. When the engine is idling, the spring is hanging loosely...

[Roflhat]

I emailed tough dog last week and he said they no longer make them for VW applications.

I've lost track of what you guys are arguing about, but even I can see how these things work, and I'm no engineer (yet).
PhillipM, why not try a set and report back?

[Piledriver]

Once we started talking, we came to the understanding that they work roughly similar to dual spring coil overs, and discussed other ways to implement ~the same thing if you have two adjustable torsion bars or along the lines of the split//locked center swaybars I proposed as an alternative back at the beginning of the thread.

...although the ease of installation//setup and the ability to preload/unload the suspension seems to make a significant difference.
(you cannot not preload dual springs on coil overs against each other AFAICT, they only push)

That little trick seems to make a significant handling difference, they no longer seem to have an annoying step transition.

The spring and ends (no shock) setups used to go for ~$25-50ish/axle back in the day...
You could probably duplicate it for <$200 using off the shelf springs and some fabricated mounts, although it would be great to have the original castings available.

[KentT]

I emailed tough dog last week and he said they no longer make them for VW applications.

I've lost track of what you guys are arguing about, but even I can see how these things work, and I'm no engineer (yet).
PhillipM, why not try a set and report back?

I asked Tough Dog specifically what was the OD of the "shock" used for their stabilizer, and the spring rates on their springs. If the bottom mounts would fit a VW shock, the springs could be cut to the desired length... That I was looking for a potential "add-on" and not an "off-the-shelf" product...

As far as the English language lectures -- I made the mistake in saying that these 4-ways provide additional damping of the primary torsion bars/springs as they either help push/pull the suspension back to its centered, at-rest position when it tries to bounce or oscillate. And then the "lessons" began...

[PhillipM]

...although the ease of installation//setup and the ability to preload/unload the suspension seems to make a significant difference.
(you cannot not preload dual springs on coil overs against each other AFAICT, they only push)

That little trick seems to make a significant handling difference, they no longer seem to have an annoying step transition.

You just offset the locking ring an inch from the ride height.

And no Kent, the lessons began when, instead of admitting you got it wrong when saying they changed the damping, you went around circles arguing your were right instead of just saying you were wrong. Still no pictures of this governer I notice? None of that math? None of those graphs?
Colour me surprised.
This:

I made the mistake in saying that these 4-ways provide additional damping of the primary torsion bars/springs as they either help push/pull the suspension back to its centered, at-rest position when it tries to bounce or oscillate

..is true of every spring holding the car up. A single stiffer spring would help push/pull the suspension back to rest faster too, a normal additional spring would do the same. Tells you nothing.

Roflhat, if you think I don't see exactly how these work (even Piledriver has come to see they do just work as switched springrates, despite our disagreements), you are more than welcome to come down and call in the workshop and I'll show you exactly how they do and why, I can even match the system with various normal coilover and torsion bar systems and put them all on a spring tester and print you matching graphs out from the lot.
I'd be interested to see why you disagree with me over them, I have plenty of time to explain to anyone wanting to learn, I just have none at all for those blinded by their own faith.

[KentT]

The spring and ends (no shock) setups used to go for ~$25-50ish/axle back in the day...
You could probably duplicate it for <$200 using off the shelf springs and some fabricated mounts, although it would be great to have the original castings available.

I remember paying over $100 (but most definitely under $200) for a complete set of four, including OEM-replacement type oil shocks. Now that I think more about it, mine came labelled Front and Rear, and since the swing-axles used the same shocks front and rear, that tells me that the spring rates used for 4-ways was likely the difference. The rears likely had stiffer springs...

That would make sense.

Did you ever swap your front and rears, to see if that helped the bit of bounciness you were experiencing in the front?

[KentT]

Colour me surprised.

No, I'll just color you conceited and convinced of your own infallability...

If you don't understand that governors do not control idle, there no point in discussing it further...

[PhillipM]

I could say the exact same thing about yourself, you're so blinded by how you think they work you won't do any research, diagnosis or math to even confirm it's true. We've got a mythical governor that only you've ever seen and I have to accept your word on how it works despite you having to Wiki damping earlier, and dismissing both the relevant description and both OED ones, and then contradicting all the posts where you were arguing about them changing damping with your previous post saying you simply mis-spoke in one post - that's not what the past 2 pages say.
There's a reason I'm convinced of my own infallablility, it's because all the math, physics and definitions agree with exactly what I've been saying.

As for your edit, there are dozens of governors that control idle, the idle stop is used as a dead stop in the event of failure and the governer idle is set just above it to keep a smooth, regulated idle speed. And unlike your mythical one, there's still lots in service so if you hit google I've no doubt you'll find plenty of examples.

[KentT]

Glad you admit your conceit, at least...

[PhillipM]

Pity you can't see your own.

[KentT]

Pity you can't see your own.

I don't pretend to be infallible, especially about things I've never experienced, so I have nothing to admit...

I'll await your "last word" since you seem to require getting that in... Hopefully you'll show me the math of how a governor controls idle...

[PhillipM]

Well, since your waiting, as I've said, I've run the same system myself for years by emulating it with the torsion bars, perfectly possible, exact same results. Mathematically provable and physically verifiable as the equivalent.

Still, you seem to be quite happy being infallible about dampers, when you appear to have little understanding of even the definition, never mind the way they actually work, so it's not just me. The only difference is, I'm right. And I can prove it, and so can anyone else on this thread with a bit of basic math, it's as simple as that.

[itawolf]

less rant more pics

LoL

[Piledriver]

Yes, I swapped the springs back to front to go softer up front, although according to a couple online spring calculators, they are around the same rate as they are 2 coils shorter, despite being somewhat smaller wire.

That's when i remembered to pull the rear down some against the torsion springs.
(This is what you cannot do with only dual compression springs on coil overs)

I still want to play with the front preload, some pull down preload may soften things up out front as well.

There is an effect that may be confusing us:
Spring rate vs. required damping: Some reading seems to indicate higher rate springs need less damping.
(oscillation frequency is higher so damper is more effective or somesuch)

This could be from reading too much online and not enough textbooks.