What the 'Fric' is it?

[DaveW]

FRIC may be the hydraulic equivalent of electronic damper control.

That is a good find, ringo. So far as I can tell, the BMW damper units are made by KW, using a control valve designed by Ohlins (see under the CES section of this reference). If that is the case, then it is a good device that I have used successfully in a prototype boat suspension (of all things). "Magnaride" would be another technology offering similar facilities.

In any case, I think it is just a continuously variable current drive damper valve with all the "technology" encoded in the control software, using driver inputs (e.g. steering & brakes) and vehicle response measurements (e.g. strut position, vehicle accelerations). Difficult to think of a passive equivalent.

I am quite sure that F1 could take advantage of the system, but you might note that it doesn't offer steady state ride height control (BMW also offer that separately, see here).

[DaveW]

I'm guessing he means a diaphragm with pressurized gas behind it to absorb an increase in fluid volume when temperature increases so the pressure stays stable. I've used these at work to control pressure spikes in our fuel oil line durring the summer months.

A good thought.

If I can explain the basic problem of an hydraulically coupled third, with, for example, the third housing a bump rubber. The object is to engage the bump rubber when a prescribed average suspension deflection is reached (i.e. an airspeed). If the effective length of the hydraulic coupling varies with temperature (& it does), then the race engineer has no control over the airspeed that engagement will actually occur. I can't help thinking that a front/rear fluid link will have similar issues (i.e. the overall ride height of the vehicle will be temperature dependent).

[DaveW]

Just a thought that you might find interesting.

A few years ago I rig tested Alex Moulton's original prototype "hydragas" vehicle, a perfectly preserved 25 year old Mini. I wondered what that might reveal about front/rear linked suspension. I rationalized that if I identified a model of the vehicle using a heave only run, then any effects of the linking would be minimized. I could then use the model to generate a response functions of the vehicle using both heave and pitch mode excitation with an uncoupled suspension, and compare those with the measured response functions using the same inputs.

In the event, I encountered some issues with the non-linearity nature of the vertical "springs" (that I was too lazy to emulate), but I managed to achieve this comparison (both from heave inputs, red being measured, green modelled), and this (both from pitch inputs, red measured and green modelled).

I hope the first plot will demonstrate that the model was a fair representation of the vehicle when excited vertically. The second plot suggests that the effect of the coupling was to reduce the pitch mode natural frequency, increase slightly its damping ratio, and to lower both the frequency and damping ratio the hub resonance (I hesitate to call it a natural frequency, because coupling made the mode pitch specific).

[TryHard]

No disrespect to scarbs, but he's not knowledgeable on the subject of suspension clearly, neither vibration theory.
He's simply going off what he reads or is told. So i wouldn't really take his words seriously. He's doing enough for the layman to have an idea how the system may work, even though he's not 100% correct.
Until you have an engineer writing articles you wont get much insight into formula 1 technology.

Why would one believe that there are no springs on this setup?
Or dampers?
I am looking at the damper, it's colinear with the pull rod.

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

Also a damper doesn't have to look like a typical damper, it only needs to be a device that does the same thing, so if it is hydraulic, aren't most dampers used hydraulic dampers anyway? See what i'm saying.

I think if we want to figure out this FRIC thing, first we need to write down what it is we want to acheive from the F1 car suspension wise, then look on what the current none Fric system offers and what limitations it has.
After finding out the limitations, you then devise what is to be done to to reach our goals in what we want the suspension to do.
Then finally you design a system with equivalent hydraulic components and that's your FRIC.
It's to fill in those gaps that the unconnected system has.

Def agree that there is a "damper" there, as you can clearly see the hydraulic lines... whats interesting though, is that these lines (from both L & R "dampers") clearly connect to a centrally mounted cylinder under the middle of the rear box. I would guess this is the "heave" element, which is then connected in some way to the front system... going on the articles posted.

I do agree that I'm struggling to see if there is or isn't springs, that photo doesn't lend itself well to seeing the bell cranks, where torsion bars normally reside.

Really interested to follow this development, seems like a genuinely clever solution (I'm not going to say novel, as it isn't, more an adaptation of previous ideas/tech)... albeit one that has taken a long time to develop!

[abw]

I see there is more discussion of this in the main Mercedes car discussion thread. Relevant pictures, too.

[Crucial_Xtreme]

I'm guessing he means a diaphragm with pressurized gas behind it to absorb an increase in fluid volume when temperature increases so the pressure stays stable. I've used these at work to control pressure spikes in our fuel oil line durring the summer months.

Here is the full res image(right click>view image)


via Sutton Images

Chinese GP 2013(not from same angle)


via Sutton Images

[TryHard]

Those two pics aren't the same gearbox.... Tell tale is the upper front leg of the suspension, on the Merc box, it's ontop of the casing, the lower one, it's recessed into the casing. Maybe a Macca, or other Merc powered teams 'box?

[Tommy Cookers]

considering that the interconnection benefits are the USP .....

the Hydragas cars (and Hydrolastic ones) were mostly (unlike Hg as intended by Moulton) not interconnected ?
the MG F apparently can be improved by removing the interconnection

also not interconnected was the related MG Liquid Suspension Special in the 1965 Indy 500
Ferrari tried a mechanical (cable ?) interconnection for F1 around 1971

[autogyro]

We have used the mini with just the front hydrolastic units and a beam axle rear with coil overs.
It helped keep the inside rear wheel on the ground without upsetting pitch control.

[ringo]

I see both dampers and torsion spring in the hi res image. I don't know what's going on with all the hoses though. haha.
The second image is the Lotus gear box.

[mep]

The first picture is definitely from Mercedes but a couple years old. I think it was taken at the end of 2011 season.
Can anyone say for sure to which team the second picture belongs, and prove why?

[ringo]

FRIC may be the hydraulic equivalent of electronic damper control.

That is a good find, ringo. So far as I can tell, the BMW damper units are made by KW, using a control valve designed by Ohlins (see under the CES section of this reference). If that is the case, then it is a good device that I have used successfully in a prototype boat suspension (of all things). "Magnaride" would be another technology offering similar facilities.

In any case, I think it is just a continuously variable current drive damper valve with all the "technology" encoded in the control software, using driver inputs (e.g. steering & brakes) and vehicle response measurements (e.g. strut position, vehicle accelerations). Difficult to think of a passive equivalent.

I am quite sure that F1 could take advantage of the system, but you might note that it doesn't offer steady state ride height control (BMW also offer that separately, see here).

Yes for a passive system, which uses no transferred inputs other than the suspension itself, it must be a very difficult task to make something be an input variable for itself.
For all the things those other damper systems use as inputs and for control, the Fric cannot have any of them. No sensors, no solenoids, no ECU.
I guess external inputs to each damper must be from the other axle, or the other wheel, or the rocker arm angle (who knows maybe a rotary hydrualic valve on the steering shaft, or a spool on the steering rack?).
Now imagine using just these basic inputs (which aren't removed from the suspension system itself) to achieve what we think they are trying to achieve?
It's amazing. Difficult to think of a passive equivalent as you say, but i don't put it past these F1 guys to do it.

[ak21_rao]

Can someone please point out which one is the anti roll bar in the above pics.

[abw]

The first picture is definitely from Mercedes but a couple years old. I think it was taken at the end of 2011 season.
Can anyone say for sure to which team the second picture belongs, and prove why?

Second picture gearbox looks to be nominally identical to this one from the E21 thread (page 74).



The gang of Lotus mechanics around the gearbox serves as my proof that it belongs to them. Either that, or they got seriously busted sneaking into another team's garage.

[mep]

Yea that was the kind of proof I was looking for.
Thanks.

As the system originates from Lotus it is very likely that they are using some form of it too.
Interesting is that no form of damper and springs is visible at the gearbox. Everything must be inside the housing connected with that rod (or hydraulically connected somewhere else), but the space seems to be too small to house many components.