Hydrolastic individualising valves

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robanzac
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Location: New Zealand

Hydrolastic individualising valves

Post by robanzac »

I have just happened across these things on ebay

https://www.ebay.com.au/itm/15372265557 ... R6LGntv5YA

The above links to some fittings that delete the front/rear interconnection resulting in each hydrolastic unit acting individually.
(well that's my take)

Has anyone ever done this? And if so, what is the benefit?
Rob
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mab01uk
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Re: Hydrolastic individualising valves

Post by mab01uk »

Out of interest the Austin Metro Hydragas suspension was not interconnected front to rear but the later Rover Metro/100 went back to interconnection:-

Rover Metro/100 suspension details.
"In the new Rover Metro/100 application these units have been interconnected front to rear.
The interconnection gives a controlled ‘bogie action to the suspension which reacts to and absorbs road irregularities much more in the manner of a large car than the previous Metro. The flatter ride platform is in marked contrast to the existing car and handling also benefits – particularly in respect of wheel control on high speed bumpy cornering. Interconnection is by plastic pipes mounted under the floor."
https://www.aronline.co.uk/cars/rover/m ... n-details/

The history of Hydrolastic and Hydragas suspension and how they work
"Spen King liked the compact suspension units but did not understand the interconnection. This is why the Austin Metro of 1980 was not connected front to rear, although Dr Moulton did persuade the design team to link the suspension across the rear, to give better stability. However Dr Moulton bought a Metro and connected the suspension, as well as fiddling with the spring and damping rates. The result was an excellent ride and handling quality, and Rover fitted this system to the new Mk3 Metro with the K-series engine. The system lived on in the Rover 100 (updated Metro) until 1997, and in the Metro-based MGF sports car until 2002, when the coil-sprung MGTF replaced it. Many people agree that the coil sprung TF and Hydragas MGF have simillar handling but the ride is a lot better with Hydragas."
http://www.hydragas.co.uk/history.html
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Peter Laidler
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Re: Hydrolastic individualising valves

Post by Peter Laidler »

Knowing my pet hate and aversion of hydrolastic, as a concept, I was going to write a comment here. I'll keep it short but ask whether the forum flock have ever heard the phrase '...flogging a dead horse.....'

Once you have separated the hydro bag - or the unit - from another then your unit is at a crossroad. On the basis that the laws of physics tell us that you CANNOT compress a liquid, the unit can only operate by the 'lastic' part of the unit. That is by the elasticity of the rubber end caps.

On the other hand, if you do want a bit of movement, you could leave a bit of air in the unit - single unit don't forget - and....... er...... hope that in your case, nature doesn't revert to type and rise to the top of the unit.

My view of hydrolastic hasn't changed. It's a frill if not a direct fraud. Based on fuzzy logic. That it works is pure and simply a bed of fluid that is transported from one unit to another. Like two balloons filled with water connected by a bit of 3/8" dia pipe.

There are a couple of similar fuzzy logic examples that spring to mind. The CUTTS compensator and the BLISH lock

Here endeth the sermon for today.......
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winabbey
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Re: Hydrolastic individualising valves

Post by winabbey »

Peter Laidler wrote: Sun Oct 16, 2022 10:20 amMy view of hydrolastic hasn't changed. It's a frill if not a direct fraud. Based on fuzzy logic. That it works is pure and simply a bed of fluid that is transported from one unit to another.
Who cares how it works? The end result is that it works, as owners of all the hydro sprung cars worldwide (and drivers of hydro cars in motorsport) will attest.
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Peter Laidler
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Re: Hydrolastic individualising valves

Post by Peter Laidler »

Yes, I agree entirely with that statement Winabbey. But let's stop all the sheer waffle surrounding it. And more to the point, complicating it. All the pure horse shi......., er...... manure about dual chambers with different fore-and-aft rate of flow valves......

It works by the ebb and flow of an incompressible liquid* flowing between two connected balloons. And once you separate the two balloons...........
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