Ride adjusting suspension?

[Richard]

That's not in the technical regulations though, they don't specify a testing procedure for the cars suspension.

I was trying to illustrate what the rule is saying, ie only respond to forces on the wheels. A hydraulic link to the fuel tank is not a force on the wheel.

Conceptually the easiest way to think of it is to isolate forces on the wheels and see if anything happens.

[Maxion]

I was trying to illustrate what the rule is saying, ie only respond to forces on the wheels. A hydraulic link to the fuel tank is not a force on the wheel.

Conceptually the easiest way to think of it is to isolate forces on the wheels and see if anything happens.

Yes that's true, though were you to lift the car up in the air and test the suspension you're only applying direct loads to the wheels. The regulation allows for loads of any kind to the wheel to invoke a suspension response, hence why I think OP's system would abide by the wording.

A hydraulic link to the fuel tank is not a force on the wheel.

It isn't a direct load to the wheels, no. But it is an indirect one. The weight of the fuel in the car puts a load on each wheel while the car is on the ground.

As the regulation does not specify that only direct loads to the wheels may give a response to the suspension you should also be allowed to apply indirect loads to the wheels to invoke a suspension response. Hence why I think the rule in it's current wording wouldn't make OPs idea illegal.

[MarkedOne8]

I hope and I think they have asked FIA first. Remember the last year, the FIA did not hesitate to ban their reactive suspension.
Lotus had these lasers almost all the winter testing. Now we know that they were working on something serious.
They've also had those attachments on wheels. I can't believe that it helps them so much with tire preservation.

I would say it is legal.

[Maxion]

Interesting note. The rules regarding suspension changed in 2006. In 2005 the technical regulations had this to say about suspension.

10.1
Sprung suspension :
Cars must be fitted with sprung suspension. The springing medium
must not consist solely of bolts located through flexible bushes or
mountings.

The suspension system must be so arranged that its response is
consistent at all times and results only from changes in vertical load
applied to the wheels save only for movement permitted by inherent
and fixed physical properties.

10.2
Suspension geometry :
10.2.1 Suspension geometry must remain fixed at all times.

10.2.2 Any powered device which is capable of altering the
configuration or affecting the performance of any part of the
suspension system is forbidden.

And, in 2006 the rules were changed to what we have now.

10.1 Sprung suspension:

Cars must be fitted with sprung suspension.

10.1.1

The suspension system must be so arranged that its response results only from changes in load
applied to the wheels.

10.1.2

10.2 Suspension geometry:

With the steering wheel fixed, the position of each wheel centre and the orientation of its rotation axis
must be completely and uniquely defined by a function of its principally vertical suspension travel, save
only for the effects of reasonable compliance which does not intentionally provide further degrees of
freedom.

10.2.1

Any powered device which is capable of altering the configuration or affecting the performance of any
part of the suspension system is forbidden.

10.2.2

No adjustment may be made to the suspension system while the car is in motion.

10.2.3

The interesting thing here is that they basically made the rules a looser. This, to me, says that the FIA with this rule change back in 2006 wanted to give teams the opportunity to play a bit with the suspension.

[ForMuLaOne]

10.1.1

The suspension system must be so arranged that its response results only from changes in load
applied to the wheels.

The system will only response from changes in load applied to the wheel. Having the car up in the air, with an empty tank, the suspension will be in a position where the dampers are fully down and in place ( in a way they normaly were). Fill the tank, and there will be NO response by the systems, as dampers were already down and in place BUT any load applied to the wheel (when back on the ground) will no lead to a smaller effect in rideheight because of the preloaded system.

10.2.1

Any powered device which is capable of altering the configuration or affecting the performance of any
part of the suspension system is forbidden.

This system is not powered and does not power. It is simply the mass which can act when the car is on the ground. It does not act in a way that a response can be witnessed, as mentioned above, when the car is in the air.

10.2.2

No adjustment may be made to the suspension system while the car is in motion.

This will be done during pit stop, with a device that activates the valve. Pressure from the inner circle ( suspension dampers) will be released into an outer circle ( fuel tank hydraulic reservoir)

[Richard]

Hydraulic power?

[CBeck113]

Only if they use a pump. Without a motor or electrical pump the system relies on external forces. No force (or change to the force), no changes to the car. In my opinion it gets past the wording.

[marcush.]

I don´t think so.
What do you need basically? A load lowering system which will reduce rideheight over a defined time -duration of a GP and something to stop the system from lowering the car in certain circumstances .
Let´s assume it was a hydraulic cylinder lets call it a ram which is rock solid under all (!) makro sized loads -basically a hydraulic lock no bleed no lines no nothing.
Say you got a less than perfect seal of the piston to the cylinder "leaking"fluid slowly by the piston but only as temps exceed
say 30°C this all would shorten the Damper about say 4mm over race duration.voila a very simple part -easily incorparated into the damperbody and undetectable from the outside .
The lowering would just be enough to keep rideheight constant over diminishing fuelloads.
It is perfectly within the rules-no forces other than loads from the wheels working the system -and it is perfectly constant,but unfortunatelly it does not work to spec ,as it leaks a tiny bit.. well what´s 4 mm of rideheight loss.

Or maybe one could argue the normal suspension systems are illegal as they change geometry (ride height ) whereas this system is designed to keep things as constant as posssible.Your choice.

[Richard]

Only if they use a pump. Without a motor or electrical pump the system relies on external forces. No force (or change to the force), no changes to the car. In my opinion it gets past the wording.

Why should power be limited to a motor? It doesn't even need movement, an electric current could lock a electrorheological fluid inside the damper. Can we agree that would be a "powered device"?

Stored liquid pressure (aka fuel tank) using a hydraulic pipe to change suspension properties is no different to stored electric potential (aka battery) using piped electrons to change suspension properties.

[DaveW]

If latter day versions of Alex Moulton's hydragas suspension are considered legal (and they appear to be), then there is no reason to suppose that the OP's proposal, or Marcus' ideas, would be considered illegal. But then, what do I know. As Marcus points out, if applied strictly the regulations rule out all hydraulically damped suspensions, anyway.

[Richard]

I think marcush's version is perfectly legal because all the energy comes from the wheel forces, and the spring rates are not changed by an external agent (other than the force applied though the wheels). Even a conventional metal spring and damper decay over time, no reason why a hydraulic system shouldn't either. Of course there would be an argument with the FIA over what is reasonable decay!

I'm not sure about hydragas if it is pumped up by the wheels and then uses that stored energy to level ride height like a Citroen. Storing the energy becomes a powered device? Obviously conventional springs stores energy for a fraction of a second so there'll be another argument about a suspiciously large cylinder that holds it's pressure for a minute or so!

Mind you, doesn't the J-damper store energy with its spinning wheel?

[bill shoe]

Everyone here is thinking logically, but stop. The public rules are simple and clear but the FIA, several seasons ago, issued a clarification or technical directive or something that creates limits beyond the regular rules. I don't know the wording (it's not public) but it says something to the effect that systems that return to (or maintain) a consistent average ride height for long periods of time are banned.

Putting this in specific technical terms would require languge that banned the suspension from having any response slower than x cpm, where x might be 30, or 10, or some such frequency that's below the range typically associated with car suspension. But the FIA doesn't define it, they just say no. I'll skip my soapbox about non-public non-defined rules.

As a practical matter the paddock understands the intent of the FIA clarification pretty clearly, but it could be difficult to enforce for many reasons, starting with the difficulty of detecting it or proving that some component that happened to have some long-term hysteresis or creep (for example) was actually intended to violate the no-ride-height-control rule.

[hollus]

I agree that it would never fly, but letter of the rules in hand (and ignoring any possible hidden directive), what is the big difference between the weight of the fuel changing the suspension's properties and the cars' donwforce changing the suspension's properties? (Like bottoming something into a rubber bump, which is often done and legal).

[hollus]

Changing the subject a little, how about changing your suspension's behaviour as the race progresses by some other means than the passage of time or the disappearance of weight?
One could use temperature to change the viscosity or volume of a fluid or the pressure inside a chamber. Now that many teams are rumored to have some sort of interconnected suspensions, and thus, at the very least, pipes crossing the car in all directions...

There's certain parts of the car that provide convenient heat sources, and that rather than adjust themselves overtime, are under the direct (or indirect) control of the driver at all times. So the driver could (as a secondary function, of course!) adjust said temperatures as needed, in response to a changing fuel load, or even in response to the wear of the tires during a stint.

One such adjustable heat source are the KERS batteries, and the part affecting suspension's behavior could simply be packaged next to them. Give them a heavy duty cycle, they get very hot (and everything around them), give them a light duty cycle, they get colder. So you could use full KERS, or use KERS in a wasteful way, when you want them hot; light (less HP, slower discharge?) or no KERS when you want them cold.

The KERS settings are controlled from the steering wheel, and, should one need it to overtake or defend once or twice, one can always adjust it to max for a while, as the temperatures around it change only slowly.

[ForMuLaOne]

Changing the subject a little, how about changing your suspension's behaviour as the race progresses by some other means than the passage of time or the disappearance of weight?
One could use temperature to change the viscosity or volume of a fluid or the pressure inside a chamber. Now that many teams are rumored to have some sort of interconnected suspensions, and thus, at the very least, pipes crossing the car in all directions...

There's certain parts of the car that provide convenient heat sources, and that rather than adjust themselves overtime, are under the direct (or indirect) control of the driver at all times. So the driver could (as a secondary function, of course!) adjust said temperatures as needed, in response to a changing fuel load, or even in response to the wear of the tires during a stint.

One such adjustable heat source are the KERS batteries, and the part affecting suspension's behavior could simply be packaged next to them. Give them a heavy duty cycle, they get very hot (and everything around them), give them a light duty cycle, they get colder. So you could use full KERS, or use KERS in a wasteful way, when you want them hot; light (less HP, slower discharge?) or no KERS when you want them cold.

The KERS settings are controlled from the steering wheel, and, should one need it to overtake or defend once or twice, one can always adjust it to max for a while, as the temperatures around it change only slowly.

Thats interesting, because you do not use power, you want to use energy that changes the reactivity of the suspension. I do not know enough about that topic, but in fact you do not apply forces in this case, but energize the hydraulic oil ( temperature) thus changing viscosity. Very smart to me