What the 'Fric' is it?

[Blanchimont]

The reason the dampers are basically on the pull rod...

Could this be for ride height control...?

This is how i understood FRIC!
It's a system to avoid or limit pitch and roll during hard braking, acceleration and cornering to stabilize aerodynamics and as a consequence you'll get shorter braking distances and higher cornering speeds.

If you were able to close certain valves in the damper (front under braking, rear under acceleration, outside under cornering) and limit the hydraulic flow and displacement only by using the occuring g forces, this would be the FRIC in theory.

[Tim.Wright]

It just occurred to me....

http://www.f1talks.pl/wp-content/galler ... kor948.jpg

The reason the dampers are basically on the pull rod...

Could this be for ride height control...?

I am assuming that the damper is chambered in a way to increase pull rod length. If it is not on the push rod and is on a bell crank instead it wont give an effective increase or reduction in length, the bell crank ratio would have a say.

Also if your damper is on the pull rod. It will have no effect on the spring. This is more crucial!!!

A damper on a bell crank, if it has a change of lenght and pushed the crank to increase ride height. It will have to go against the spring force.

A usually change in ride height is all adding shims to a pull rod or screwing an adjuster nut.
This damper in this diagram is not only a damper, but it is a length adjuster.

A possible route to explore is if the damping of the car is much different than FRIC. Fric may be a separate system that simply shares the damper body. Maybe it is compounded with the damping of the car, but it can be likely that it has it's own hydraulic circuit separate and apart from the damping fluid. it may only use the damping fluid volume and speed as inputs to control rate of ride height change and also the displacement.

Make sense?

edit: i spoke too soon, i could have a few errors, i'm going through some diagrams. but the idea still holds.

Nah, there is no difference between between mounting the damper inline with the pull rod and mounting it somewhere else. The damper is not "basically on the pull rod", its on the rocker exactly the same as any other pull rod system, but in this case with perhaps a different motion ratio.

[autogyro]

I disagree Tim.
With a hydraulic system for suspension bump and droop the damper can be anywhere on the hydraulic circuit.

The pull rod geometry gives hydraulic displacement of fluid over the suspension travel.
This allows the hydro/pneumatic springing and the hydraulic dampers to be located anywhere on the car.
If you add a fluid dispplacement unit under the fuel load coupled to all four hydraulic rods, you have a way of maintaining ride height from full to empty.
Reaction valving with direct input from G force and suspension movement will allow control of spring hardness and damper effectiveness for roll and pitch control.
Great, now make it work in less than two years and work out how to set it up.

My hydro Mini (1978) had a beam axle with coil overs on the rear, so we only had to play around with the two front displacers.
That was hard enough.

[Dragonfly]

On that photo of the Mercedes what do you think is the black cylindrical object beneath the differential and connected with hoses to the pull rod rocker assembly?

[Tim.Wright]

Probably a hydraulic accumulator and/or valving unit for the interconnection of the left and right suspensions. Might even be connected to the front suspension too but its not so clear in that picture.

None of this is new technology. It similar to the old Kinetic (now owned by Tenneco I believe) suspension system. Below you will see two accumulators in such a system. What they are doing would be something similar, but the exact plumbing is impossible to know really.

[autogyro]

Just add the fuel tank variable load for ride height and you have got it Tim.
At least the basics.

Sorry to sound big headed yet again but I have an idea for an electromagnetic suspension system that could also be passive.
Had it on the back burner for over a decade.
We thought it up after playing with the electromagneticaly activated fluid that Tony Rudd discused with me when Lotus were looking at using it in fluid clutch packs.
All that was before hybrid and electric vehicles and electric energy recovery in F1 so we had no large electrical storage on board.
Its different now of course.
Damn regulations would probably outlaw it though, so yet again nobody is going to risk money on 'proper' development and things will remain stagnant.

[Tim.Wright]

How exactly are you suggesting the fuel tank is incorporated here? I don't see it.

[ringo]

Nah, there is no difference between between mounting the damper inline with the pull rod and mounting it somewhere else. The damper is not "basically on the pull rod", its on the rocker exactly the same as any other pull rod system, but in this case with perhaps a different motion ratio.

I see your point. This was a possible error i mentioned earlier. However i will show what i was thinking.

Let's start by comparing a damper in series with a spring, then in parallel with a spring.

Then what we will do next is the same comparison, however the damper will have a hydraulic ram/actuator in it where the length can change. (this internal ram is the FRIC component, its displacement is driven by the FRIC system).

I'll add the diagrams later, i'm busy at work.

[ringo]

On that photo of the Mercedes what do you think is the black cylindrical object beneath the differential and connected with hoses to the pull rod rocker assembly?

It could be an accumator with a hydraulic dsiplacement differentiator.

Now that's a mouthfull, but this is what i mean.

Accumulator with either air spring, or coil spring.
DIsplacement diffeential/differentiator as in when fluid comes in from on corner or one axle, that dispalcement is reduced or increased and then imparted on the fluid for the other corner or other axle. This is done by the spring, or valving.

I will try my hand at a diagram later with a few basic equations. This is good practice as my vibration theory is rusty.
Note; I'm no suspension expert, so if there is any input of realistic info, feel free to add to it.

[DaveW]

Sorry to sound big headed yet again but I have an idea for an electromagnetic suspension system that could also be passive. Had it on the back burner for over a decade. We thought it up after playing with the electromagneticaly activated fluid that Tony Rudd discused with me when Lotus were looking at using it in fluid clutch packs.

Aura Systems, I recall (now defunct, I think) patented the idea over 25 years ago & I believe produced a prototype. More recently, Bose have laid claim to something similar - probably the same system, because "they" have been working at it for over 25 years (apparently)....

[DaveW]

I will try my hand at a diagram later with a few basic equations. This is good practice as my vibration theory is rusty.

Good stuff, ringo. My earlier reference to a thesis published by Razenberg might help, with both diagrams & equations....

[autogyro]

Sorry to sound big headed yet again but I have an idea for an electromagnetic suspension system that could also be passive. Had it on the back burner for over a decade. We thought it up after playing with the electromagneticaly activated fluid that Tony Rudd discused with me when Lotus were looking at using it in fluid clutch packs.

Aura Systems, I recall (now defunct, I think) patented the idea over 25 years ago & I believe produced a prototype. More recently, Bose have laid claim to something similar - probably the same system, because "they" have been working at it for over 25 years (apparently)....

No Tim that is an electronic damper system.
The system we were working on was the complete suspension using fluid as the operating medium.
I first spoke to a certain Mr Chapman about it and other matters at Elstree flying club over lunch.
Late 1970s if I remember.

How to maintain a constant ride height using hydropneumatic suspension should be fairly obvious.
Making it work reliably is the problem.

[Dragonfly]

On that photo of the Mercedes what do you think is the black cylindrical object beneath the differential and connected with hoses to the pull rod rocker assembly?

It could be an accumator with a hydraulic dsiplacement differentiator.
................

I also think so, and that's why I asked this question.
Ringo, I don't have the technical background many of you have here. But I own and drive an aging Citroen "Xantia". I took it because I was curious about the suspension since I was a boy. Initially it seemed complicated, but now I know it and it is a relatively simple and reliable thing.
By Citroen terminology this is a "sphere" (IMO), which can either be a dedicated accumulator or a act as a spring and a damper 2 in 1. On a Citroen the left and right wheel are interconnected by the tubing for each axle. There is no interconnection between front and rear. On the so called "hydroactive" variation there is a third "sphere" for each axle which can be connected or disconnected from the common pipe contour by means of a valve. If all 3 are connected, the suspension is soft, if the third is disconnected, it becomes stiffer. This is achieved by different gas pressure (different spring rates) in the side ones and in the middle one. Also the damping holes and valves are different.
So I was thinking about a similar principle - connect or disconnect an accumulator to the hydraulic circuit and obtain different characteristics. And I presume it can be achieved in a passive manner by just using valves and switching routes for the hydraulic liquid. For adjusting spring rates they can simply use different pressures, and by changing a simple block with calibrated holes and leaf valves on it - change the damping characteristics.

As a side note: self leveling on a classic Citroen is a pure mechanic solution - 3 way valves connected to the anti roll bars (front and rear) and activated by their twisting under a changing load. With more load hydraulic liquid is fed from a high pressure accumulator to the hydro cylinders, acting as struts until the roll bar moves back to normal position. On less load, liquid is bled from there.
The only thing I see as not compatible with F1 rules is that the system has a pump which keeps the main accumulator full and under the desired pressure, as the bled liquid i returned to the tank.

P.S.
If someone is interested there are many sources on the net. like this one
http://www.citroenet.org.uk/miscellaneo ... ics-1.html

[DaveW]

Sorry, off-topic again, but I couldn't resist.

No Tim that is an electronic damper system.

I think that Bose would claim rather more... see this.

How to maintain a constant ride height using hydropneumatic suspension should be fairly obvious.

On topic again, perhaps you could explain how. We can worry about reliability later.

[ringo]

I will try my hand at a diagram later with a few basic equations. This is good practice as my vibration theory is rusty.

Good stuff, ringo. My earlier reference to a thesis published by Razenberg might help, with both diagrams & equations....

That's more than enough info! it's just to sift through and tailor something out of it.

edit:

I see what is happening now, and i understand why some may have been mixing up their hydraulic fluid with a spring.
Bluntly, the fluid is not the spring. It is the air in the accumulator that can act as a spring. How this translates to F1 i don't know. Also a strut body must exist, and this is what we see in the 2010 suspension picture.
The damper body now, can be a valve block, and the accumulator may be that bottle on the back of the gear box.

The catch is, this system is no different than a mechanical system if it is passive. In fact it could be more unpredictable as the spring rate, which is based on ideal gas laws will vary with temperature. The spring force can be predicted for any instant and will change dramatically for reduction in fuel as the car does laps around a track, however the spring rate is a different matter.
Ride height control now is interesting as fluid will need to be introduced. The good thing is that introducing more oil does not affect the spring forces.
Can this oil be introduced passively?
Interesting stuff, but i'm yet to see how a passive hydrodynamic suspension has any advantage over a more mechanically efficient conventional system. This is why i feel the 2013 FRIC may be more geared towards ride height than to replace all suspension components. Because it clearly takes up more space and ir-reversibility in an air spring will be noticeable.