What the 'Fric' is it?

[Dragonfly]

Can the same mechanical accelerometer change stiffness of hydraulic/gas spring?

As I said earlier, I think it's possible - by connecting or disconnecting a third hydropneumatic block to the hydraulic lines. As it is done for many years on some road cars. With the third spring (and remember it is both a spring and a damper 2 in 1) we have the wheel ones combined in parallel with it and the suspension is softer. When under acceleration disconnecting the third block results in stiffer suspension.

[Pup]

So why would you need a third spring/damper (and why would it need to be hydropneumatic if it's just being switched on and off)? Why not use a damper with dual circuits like I posted earlier? Same philosophy, but with the added benefit of valving at all four corners and therefore variable damping in cornering as well as braking/acceleration.

It just seems to me that you could get the same benefits of a cross linked system without the need for cross linking.

[Dragonfly]

I guess there are number of ways to design a suspension with the desired behavior. But because the FRIC is said to be using hydraulic links and pneumatic springs I just tried to show a way to achieve variable suspension behavior. Further than that, I am afraid, my knowledge is not sufficient.

[korzeniow]

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)

http://formula1.com/wi/enlarge/sutton/2 ... kor948.jpg
via Sutton Images

Chinese GP 2013(not from same angle)

http://formula1.com/wi/enlarge/sutton/2 ... chn163.jpg
via Sutton Images

The second image is Lotus' 2013 gearbox, not Mercedes'

[DaveW]

This thread appears to have run its course.

It has been very helpful for me, so many thanks for the varied contributions (some I agreed with, others not, but all were interesting). I have now developed (what I think is) a working model of the front/rear coupling so I should be in fairly reasonable shape to interpret what I measure when I do actually meet one.

A few of thoughts:

With a 2+m pipe(s) connecting front & rear suspensions, there seems to be no way the coupling can affect suspension dynamics in any meaningful way, or even control dynamic warp loads although, to be fair, my model of the fluid flow dynamics is primitive...

With a relatively low charge pressure there appears to be a need to maximize fluid displaced per unit of suspension movement, and that might imply the adoption of a hydropneumatic spring (as per Citroen), particularly at the rear axle. I still would prefer to see bars at both axles, however.

Of the three "journalistic" views referenced here, Garry Anderson's seems to be closest.

Overall, the model seems to confirm my first impressions.

[techF1LES]

[Source] Minardi claims it ran 'FRIC' back in 1993 on Minardi M193



Former Minardi and Scuderia Toro Rosso engineer Gabriele Tredozi on 'FRIC': "Firstly, you have to go back twenty years, when active suspension rapidly gained popularity. This technology had the ability to electronically manage the suspension through a number of parameters such as ride height, roll and pitch. All this was no longer done through a conventional mechanical system, but hydraulically. The system was composed of actuators placed on struts. The spring-damper actuators received hydraulic fluid pressurised by a pump and the electronic controllers handled the front and rear ride height, roll and pitch, thus obtaining a benefit in terms of aerodynamics. This project could be divided into two parts: a passive, with the hardware of the hydraulic suspension and active related to electronic controls."

"Martini's and Fittipaldi's M193 was equipped with a passive hydraulic system. There wasn’t an external pump which would pressurise the system, but the car was equipped with traditional suspension supported by hydraulics. It worked on the springs controlled by hydraulic lines with the strut that put the circuit under pressure. This was the starting point and then we made the system fully active the following year. Unfortunately, the FIA banned the system, so we found ourselves with very advanced, but not exploitable suspension. However, in 1994 we continued to use it without making it active."

"The goal was to minimize the variations in height between the front and the rear during braking and acceleration. In order to passively manage pitching of the car, we used cross-connection (link) of the front axle with the rear. In this way, when the vehicle was under braking, the front actuator created a vacuum in the back, immediately filled by the hydraulic fluid from the rear, so the rear was also pushed to the ground. Doing so kept the height difference unchanged. Cross-connection also helped in the corners. When the load was greater on the outside rear wheel, intervened on the inside front wheel limiting body roll. The same operation, but the opposite way was the case when accelerating and the load is transferred back raising the front. The pressure of the actuators avoided it pushing the nose down to the ground. Doing so decreases the understeer during acceleration."

"At the end of 1993, however, interlinked system was banned. With the M194 then we continued with the hydraulic suspension, but no longer connected. A portion of the benefit was therefore missed. On the other hand, today's Formula 1 has reappeared this link using a system similar to ours 20 years ago."

[Pierce89]

This thread appears to have run its course.

It has been very helpful for me, so many thanks for the varied contributions (some I agreed with, others not, but all were interesting). I have now developed (what I think is) a working model of the front/rear coupling so I should be in fairly reasonable shape to interpret what I measure when I do actually meet one.

A few of thoughts:

With a 2+m pipe(s) connecting front & rear suspensions, there seems to be no way the coupling can affect suspension dynamics in any meaningful way, or even control dynamic warp loads although, to be fair, my model of the fluid flow dynamics is primitive...

With a relatively low charge pressure there appears to be a need to maximize fluid displaced per unit of suspension movement, and that might imply the adoption of a hydropneumatic spring (as per Citroen), particularly at the rear axle. I still would prefer to see bars at both axles, however.

Of the three "journalistic" views referenced here, Garry Anderson's seems to be closest.

Overall, the model seems to confirm my first impressions.

Any chance we could see a sim comparison of pitch and roll control as compared to a traditional(non linked) system?

[ringo]

"The goal was to minimize the variations in height between the front and the rear during braking and acceleration. In order to passively manage pitching of the car, we used cross-connection (link) of the front axle with the rear. In this way, when the vehicle was under braking, the front actuator created a vacuum in the back, occupied by the oil from the rear, so the rear also crushed to the ground. Doing so kept the height difference unchanged. Cross-connection also helped in the corners. When the load was greater on the outside rear wheel, intervened on the inside front wheel limiting body roll. The same operation, but the opposite was the case when accelerating and the load is transferred back raising the front. The pressure of the actuators avoided it squeezing the nose to the ground. Doing so decreases the understeer during acceleration."

Good find, it adds a lot of material to the discussion. I find that vacuum part interesting though, and i'm trying to visualize it.
It looks like pitch control is the greater benefit.

[ringo]

Well, might as well look into the past since there is a connection.

What's going on here?

ride height control ?

[thisisatest]

i could be missing something obvious, but it just looks like a pullrod bellcrank system. the dampers have large remote reservoirs. transmission/diff oil cooler. funny round can in the middle, vented out back.

[ringo]

It does appear so.
The previous car to this one had similar suspension bar the remote reservoirs.

[Tim.Wright]

Looks like a pretty normal suspension to me

[timbo]

I remember Tyrrell running some sort of tricky suspension during 1995.

[gt6racer]

Hi,
Neat discussion.
I've seen a lot of discussion regarding pitch reduction effect of the FRIC and understand the advantages, but I've not seen discussion on the additional possibility of switching the hydraulic connections as relayed in Scarbs rear susp. article : http://scarbsf1.com/blog1/2011/10/17/me ... uspension/
Are there any thoughts as to whether the FRIC system is also changing plumbing connections for roll or pitch modes, and if so, how such switching might be triggered ?

[flyboy2160]

....if so, how such switching might be triggered ?

I haven't looked at a moog valve cutaway in many years, but going from memory, how about entering mechanical perdition and replacing the electro-mechanical solenoids that displace the magic finger with some lateral G sliding/rolling/bending weight on an arm gizmo. good luck setting it up and having it work reliably. (i'll have to look up a valve schematic before any of you take this seriously....)