A hydraulic suspension system?

[gridwalker]

The hydramatic system showed lots of promise and it was considered by Lotus for F1 use. Of course the Lotus development ended with fully active suspension for ground effects with tunnels and skirts and then twin chassis'. Followed shortly after by a ban and the death of chunky. A sad loss. IMO F1 has come little distance since.

Lotus started researching active suspension in 1981, intending for it to be used to maximise ground effect. Unfortunately, the flat bottom rule was introduced in 1983 before the system was ready to race (so there could never be a tunnels/skirts/active triple hit combo).

During the 1983 season, Nigel Mansell ran the active system in 2 races before it was dropped for performance reasons. Lotus then returned to traditional suspension setups until 1987, when Ayrton Senna won 3 races in the active 99T.

[DaveW]

The hydramatic system showed lots of promise and it was considered by Lotus for F1 use. Of course the Lotus development ended with fully active suspension for ground effects with tunnels and skirts and then twin chassis'. Followed shortly after by a ban and the death of chunky. A sad loss. IMO F1 has come little distance since.

The Lotus Active Suspension project started only after the '88 had been abandoned, Auto.

During the 1983 season, Nigel Mansell ran the active system in 2 races before it was dropped for performance reasons.

True, but might be misleading as stated. Lotus had planned to use Renault engines & active suspension for 1983, but Renault refused to allow an hydraulic pump to be attached to its engine. The season started with a passive/Renault car, an active/DFV car & a passive/DFV spare. It is probable that there were economic reasons for the mix of engines (the Renault produced, I recall, around 150hp more than the DFV at the time), but it did allow some race experience to be gained with active suspension. The active car was, unsurprisingly, slower than the Renault engined car, but a back-back test during Long Beach practice ("street" circuit) demonstrated the active DFV to be around 3 seconds quicker than the passive DFV. A full complement of Renault engines was used after Long Beach, I think, which meant that active suspension development continued elsewhere.

... until 1987, when Ayrton Senna won 3 races in the active 99T.

Two races, I think, GW, Detroit & Monaco.

[xpensive]

Back on track after little bit of empirical research of the Citroen idea together with my new Trondheim mistress.

Now, if we can try to behold the hydraulics as a a conveyor of force only, while the compressible gas gives the spring-effect, what if the amount of hydraulic-fluid could be controlled in an orderly fashion to adjust the ride-height?

[DaveW]

Now, if we can try to behold the hydraulics as a a conveyor of force only, while the compressible gas gives the spring-effect, what if the amount of hydraulic-fluid could be controlled in an orderly fashion to adjust the ride-height?

X, you are describing the Williams GP semi-active system of 1987, I believe. I'm told it included parallel steel springs - I guess to provide rate adjustment & a "soft" landing in the event of a failure.

[timbo]

the Tyrell, Marcus has mentioned, is 023 and the system was called "HydroLink".
They made quite a dance about it, but droped it later in the season, as it did
not showed the advantages on track, the system should theoretical have.

I remember hearing that.
Do you have any more info on that?

[DaveW]

I believe I saw the basis of that as an "hydraulic rocker". A neat & clever idea that had two problems from my observations, friction & stiffness (too much of the first, too little of the second).

[autogyro]

The hydramatic system showed lots of promise and it was considered by Lotus for F1 use. Of course the Lotus development ended with fully active suspension for ground effects with tunnels and skirts and then twin chassis'. Followed shortly after by a ban and the death of chunky. A sad loss. IMO F1 has come little distance since.

Lotus started researching active suspension in 1981, intending for it to be used to maximise ground effect. Unfortunately, the flat bottom rule was introduced in 1983 before the system was ready to race (so there could never be a tunnels/skirts/active triple hit combo).

During the 1983 season, Nigel Mansell ran the active system in 2 races before it was dropped for performance reasons. Lotus then returned to traditional suspension setups until 1987, when Ayrton Senna won 3 races in the active 99T.

I am sure you are correct gridwalker, it is a long time ago but I distincly remember discusing active with Tony Rudd in 1980 or it might even have been 1979.
We talked about a Swedish tank, gyro stabalized gun turrets, the potential for military use and its lack of potential for road cars, due to cost, complexity and the limited benefit for ordinary vehicles. The F1 application was secondary at that time. We shelved the option of an active racing saloon for cost reasons.

[747heavy]

the Tyrell, Marcus has mentioned, is 023 and the system was called "HydroLink".
They made quite a dance about it, but droped it later in the season, as it did
not showed the advantages on track, the system should theoretical have.

I remember hearing that.
Do you have any more info on that?

Unfortunately not much Timbo, I was trying to find some pictures, but with no results
so far.
Here are some comments about the system.

http://www.xs4all.nl/~rvreekum/ty07f.html
February 1995
http://www.grandprix.com/ns/ns00026.html
July 1995
http://www.grandprix.com/ns/ns00222.html

the system das designed in cooperation with Fondmetal (Technolgies)

[timbo]

Thanks!

[riff_raff]

xpensive,

While your idea is technically feasible, it would not be advantageous for F1. One of the most critical things with F1 suspensions is consistency and predictability in set-up. A mechanical linkage system with hydraulic damping is very consistent and predictable in terms of stiffness, structural frequency, damping rates, etc. A system that transfers/reacts forces mainly via hydrostatics and pneumatics would be much less predictable or consistent, due to the variables such as temperature, viscosity, and flow losses.

Regards,
riff_raff

[autogyro]

xpensive,

While your idea is technically feasible, it would not be advantageous for F1. One of the most critical things with F1 suspensions is consistency and predictability in set-up. A mechanical linkage system with hydraulic damping is very consistent and predictable in terms of stiffness, structural frequency, damping rates, etc. A system that transfers/reacts forces mainly via hydrostatics and pneumatics would be much less predictable or consistent, due to the variables such as temperature, viscosity, and flow losses.

Regards,
riff_raff

Nicely put riff_raff and basicaly true.
However, if you look hard at the history of hydro/pneumatic suspension in F1, you will find occasions when improvements to the cars handling were achieved. Continued development was mainly prevented by the changing regulations.
IMO it is possible today to design an 'active' system using electronic control to overcome the negative aspects you mention with little difficulty.
The main problem as always is, will the 'spec' regulations allow any future for the idea. In a way F1 has become a block to future technology IMO.

[alexbarwell]

Throwing this into the mix - if the hydraulic link were as a transfer system to an inboard spring/damper with opportunities to orientate the action of inertia, if the tube bore/length/capacity were critically tuned then an element of vascilation (?! meaning small amplitude high frequency deviations)could be addressed much in the same way as tuned mass damping. Some heat would be developed in the fluid, but that happens to the brake fluid in any case as it gets pretty close to some quite warm discs...

[netoperek]

alexbarwell, could You please put Your post in different words? i just don't get what You mean (English is not my native language, sorry). You mentioned high frequency deviations... i doubt if there is any HF noise transfered through hydraulic system. To my understanding, it works just like low-pass filter, just like any other low order intertial system.