What the 'Fric' is it?

[gixxer_drew]

With a system like this you can program the attitude to aero load response. In essence where it carves through the aero map gets tighter control. There are more and less desirable parts of the map in terms of pitch sensitivity, aero balance, everything that matters. Which as you mentioned always has the side effect of letting mechanical work better and compromise less but there is a huge list of aero benefits as well beyond the obvious.

Starting with CoP shift, you have a target balance range. It needs to be adjustable and also needs to be set in the middle of the range it walks to on its own as the balance shifts with speed. So lets say you know the aero balance will be 55-60% rear (base adjustment) you need to optimize the front wing to work through a range of adjustment that the driver might need. In your designs you need to target a max efficiency and down force across that range, not just at one angle of adjustment. Now you can program to slice through a certain part of the aero map you can reduce that to say two percent adjustment range instead of five, you optimize more tightly for a smaller range.

Your front wing gains efficiency straight away from the smaller range needed to design for. Next thing is, you devote so much accuracy and time to the downstream effects of a front wing to the diffuser and all the other devices in its wake. Think of how many of your design iterations you are devoting to needing to test across a front wing adjustment range. Test quantity (WT and CFD) is a multiple of the ranges. If in a month you do 100 tests and all of them had to be run at three adjustment points for front wing. Now, say you reduce that from three points of adjustment to just two. You have just cut the need for 33 of those tests needed. You now test 1/3rd more ideas than your competitor. Then more tests return positive results because that extra 1/3rd of tests might work in the other 2/3rds of the adjustment range but not in the last 1/3

You progress at a rate per quantity of tests. Everything is about optimizing the number of tests you perform with your given resources. If they are doing that in CFD its compute time gains for sure. Im sure their wind tunnels at that level sweep through the range automatically and dont require a stop start to change the settings but especially if they are testing adjustment range in CFD the gains can be large in terms of aero development.

I would want to play with trick things as well in how I program the ride/load response. I’m sure the plank wear problem is really centered around the nose of it and the 1mm maximum is a small number. Jabroc is a very low friction material. If you can control the car up in such a way that after you are above the air speed of any corners the attitude goes nose up and the rear drops you can get the jabroc sliding flat across the straight reducing the nose wear. Spreading wear evenly and then have it respond to braking in such a way the nose of the plank doesn’t push as hard into the ground. I think red bulls "big secret" is whatever devices they have in the back to keep the rear diffuser working without being close to the ground to allow the front wing closer to the ground via rake. Spreading around where on the plank it is wearing means you spend more of a lap time at the lower ride height before you have worn too much.

I believe F1 plank is different than LMP in that it does not get as close to the front axle center line. As the car settles the front of the plank gets closer to the ground right, but if you lock the front ride height at some point and settle only the rear the plank still gets closer to the ground. So you have to lock the front suspension down earlier than optimum but with a programmable response you can get front to come back up a little as the rear goes down. A lot of ideas like that, may or may not work but I would want to look into them if I had a system like that.

Choosing in a less pitch sensitive part of the map can increase your average aero loads across a lap as well... a lot of work is done there.

When you talk about 7mm.... I don’t have a sim model for an F1 car but I have cars with similar or higher downforce and if I dropped my RH by 7mm average across a lap it is a huge chunk of lap time.

[gixxer_drew]

No comments? Am I off in outer space with this?

[tuj]

Everything is about optimizing the number of tests you perform with your given resources.

This totally makes sense that the teams would want to have a system to keep ride height as constant as possible across the aero map, minimize the variations in attitude that are necessary to test in the WT/CFD.

[DaveW]

There would appear to be two schools of thought on the heave/pitch action of FRIC.

The first, outlined by RideRate follows the Kinetic idea which (notionally, at any rate) resists pitch displacement, but allows heave displacement. Here the FRIC interconnection is "crossed over", which implies that a reduction is front ride height causes (or tries to cause) a reduction in rear ride height. Can I call this the "Kinetic" (K) approach?

The second school of thought does not "cross over" the interconnection, which implies that a reduction in front ride height causes (or tries to cause) an increase in rear ride height. Can I call the "anti-Kinetic" (AK) approach?

What will happen to ride heights in practice will depend on actuator area ratios and conventional heave/pitch spring selections. I am reasonably convinced that either strategy can be made to work, in the sense of taking control over front ride height, but they will require different parameters. So which is to be preferred?

The K strategy implies that the rear ride height will tend to be increased (or reduced less) at speed (supporting the rear axle), whilst the AK strategy implies that rear ride height will tend to be reduced at speed.

At first sight, it would appear that the K strategy would be appropriate, but my gut feeling (as far as that goes) is that the AK strategy is likely to work better, provided that inflow under the car can be controlled and the diffuser flow be persuaded to remain attached at the high initial rear ride height. That should allow increased diffuser contribution to the overall D/F at low/medium speeds, the front spring rate to be reduced (helping both front & rear grip), the rear tyre (in particular) to be looked after rather better, and the rake to be reduced at high speed (helping L/D). Reducing the rear wing contribution should also help to improve L/D. All(!) that is left is to ensure that the front splitter gets out of the way and remains legal.

... But I could easily be wrong.

[dren]

This was posted by another member in the W05 speculation thread found here http://www.f1technical.net/forum/viewto ... &start=105

Btw.. Today I had a chance to sit with an insider from Mercedes who explained to me about the FRIC for next year's car. As well as Rake angles, and why Lewis has been struggling with "braking issues"

As we know Mercedes started playing with the idea at the end of 2011, then in 2012 they had full FRIC and wasn't perfected until this year where it still a bit volatile.

this is as he explained it down to the way its laid out and no, no Mercury involved..
the concept behind the FRIC mainly to aid high speed cornering mechanical grip and to complement the lowspeed cornering with tradition anti-roll bars.. yes they use both methods. the fundamental issue this year was that because its hydraulic fluids that are adjusted, i.e taken out or put in depending on how soft you want the suspension, aren't always of the same "viscosity/pressure" at the time of adjustments, usually done in FP1 and locked for FP2 they can't get it 100% all the time between both cars. simple matter being that one car maybe hotter than the other or vise-versa when making the changes on setup as its only one guy doing it, so by the time he's finished on one car, the "pressure/viscosity" has changed.
But from what he's told me they're almost got the "balance" correct on that, and when it works, like at silverstone it works brilliantly. they should have it honed over the next few weeks for the w05 he told me.
the other thing with relation to FRIC and Lewis hamilton's braking ability.. it's not that there is anything wrong with the brakes per-sey, but more over that he's not used to the FRIC system keeping the car pitched up underbraking, where like in his mclaren days you'd see that his car DIVES massively as he wants it which gives him the confidence..

[DaveW]

Thanks for the reference. That and the following posts are well worth reading.

[dren]

Yes, there is much more to learn in the posts prior, but I posted that since it states anti roll bars are still used which I thought was interesting.

[ringo]

Yup, at least there is some semblance of common sense.
I remember mentioning that the system needs all these traditional things, but i guess the fanciful ideas of liquid springs and what not was more marketable.
Reading that insight above, it seems the system is more for anti pitching than anything.

[DaveW]

A couple of thoughts on dren's reference:

I suspect that the reference to "viscosity/pressure" relates to the difficulty of pressurising the system so that the ride height is correct when the running temperature has stabilised. Quite small changes in running temperature of a closed hydraulic system will affect ride height....

The action of braking would be expected to cause the nose to drop (just as it would without FRIC). Thereafter, however, the nose will be raised by the action of the FRIC, ultimately, I suppose, to reach the original ride height (ignoring the fact that airspeed will actually be changing quickly). The rate of recovery will depend on the resistance to flow, which will, in turn, depend on the interconnecting pipe diameter and length, and any additional restriction. Perhaps LH did not like the recovery action...

If that is the case, then further restricting the flow would help, but it would be a compromise because the restriction would also slow down height corrections when changing airspeed.

[PlatinumZealot]

A couple of thoughts on dren's reference:

I suspect that the reference to "viscosity/pressure" relates to the difficulty of pressurising the system so that the ride height is correct when the running temperature has stabilised. Quite small changes in running temperature of a closed hydraulic system will affect ride height....

The action of braking would be expected to cause the nose to drop (just as it would without FRIC). Thereafter, however, the nose will be raised by the action of the FRIC, ultimately, I suppose, to reach the original ride height (ignoring the fact that airspeed will actually be changing quickly). The rate of recovery will depend on the resistance to flow, which will, in turn, depend on the interconnecting pipe diameter and length, and any additional restriction. Perhaps LH did not like the recovery action...

If that is the case, then further restricting the flow would help, but it would be a compromise because the restriction would also slow down height corrections when changing airspeed.

hmm interesting I share some of those views as well. My take on Viscosity pressure is that it is simply the viscous and frictional pressure drop due to the liquid moving through those very small diameter lines while the system is being primed by the mechanic. The faster the mechanic pumps the more pressure you will need to overcome. To make things even more unpredictable the fluid heats up as it is pumped too. With increased temperature changes the viscosity of the fluid reduces. So as you can see it is difficult to pressurize the system to a normalized pressure when you are in non standard conditions.
So I think that to allow more stable conditions while pressurizing the system the mechanic has to wait a prescribed time after pumping to allow the fluid temperature to come down to its static pressure value, then check the pressure, then pump again.

[DaveW]

So I think that to allow more stable conditions while pressurizing the system the mechanic has to wait a prescribed time after pumping to allow the fluid temperature to come down to its static pressure value, then check the pressure, then pump again.

You are probably correct, although I think it may be more than simply pipe restrictions. The sign for me of a competent truckie (they are usually entrusted with setting tyre pressures) is one who always checks the tyre pressure a second time after a change.

[Lex LFA]

So is Mercedes or any of the other teams using FRIC this year, I havent heard anything about it.

[matt21]

So is Mercedes or any of the other teams using FRIC this year, I havent heard anything about it.

As they all learned how to use it and it is not forbidden, you can be sure they are using it.

[Powerslide]

If we could get a clear answer on FRIC, if it were that simple, in a split every team would have the system on their car so here comes my little fantasy on it.

Formula One teams run their cars with its rear kicked up higher than its front. Forget mechanical grip advantage its all aerodynamics now, just look at the angle of that front suspension and it will scare mechanical grip traditionalist at first sight. They even got Ackermann puzzled with that steering geometry, ok, thats not aero related. So, the rear is raised to get more downforce at lower speeds and on the straight, that high downforce rear wing will push down the rear to squat. This changes the cars angle which also means it change the wing angle, straightening the car towards the incoming air improving aerodynamics for faster top speed. Think flexible wing era where the wings were flexing backwards changing the intent attack angle to less downforce and reduce wind resistance yet straightens itself for when speeds are reduced for more downforce. Call it downforce ratio changes or flexible downforce ratio if you will.

Then comes DRS, this reduces rear downforce when activated. The whole squat set up based on rear wing pressure now undone. So in comes FRIC, reduces roll? Reduces Pitch? Sure, but what about if I were to say it helps squat? Raise the rear, add a stopper for squat so it won't collapse. FRIC keeps suspension in tune with all requirements but softens squat relative to rear suspension's mechanical load to work with the DRS system enabling squat to straighten the car at low rear downforce level. Now then give FRIC a shock absorbent then throttle input will not disturb squat with those level of rear suspension load changes. Again, meeting all requirements of a Formula One car in pitch, roll and warp but allow heave to bring down that rear via aero downforce but all jacking is dampened.

Just maybe, DRS hydraulics is hooked up with FRIC. Activated, it straightens the car improving aerodynamics beyond a level of just DRS wing flap movement. Un-activated, it prevents squat retaining high downforce for high grip. If that can be legal, it would be immense.

[skgoa]

So is Mercedes or any of the other teams using FRIC this year, I havent heard anything about it.

We know that Caterham have been using it since last year, since there have been images of part of their system. Hydraulically interconnected suspension has been run at LeMans and there are companies who sell the parts to anyone.
It seems likely that all (or at least most) teams use such a system.

The important factor is setting it up perfectly. Apparently Merc has a huge head start.