Lotus/Ferrari brake reactive ride height

Seems to be the new "big" thing in F1 at the moment.

Any idea how it works and if mechanically operated from brakes how is it different fom simple anti -dive?

"Ferrari is awaiting an answer from the FIA on the legality of an adjustable ride-height braking system that Lotus is believed to be developing for 2012.

A report in Gazzetta dello Sport on Tuesday revealed that Lotus was running a ride height control mechanism - reported to be activated by a driver using a pedal - to help maintain the car's distance from the ground under braking.

As well as helping with aerodynamic performance, due to the constant ride height, the device would also improve stability under braking - so would therefore have the added benefit of helping look after the tyres.

When asked by AUTOSPORT at Ferrari's Wrooom media event on Wednesday about whether the Italian team was considering copying the innovation, team principal Stefano Domenicali revealed the matter was awaiting clarification from the FIA.

"What you are talking about, is more related to having stability under braking," explained Domenicali. "It is a system that I know there have been some documents in writing between the FIA and the teams.

"We are waiting for the final confirmation if this kind of devices will be acceptable or not. But for sure we are looking around these sorts of devices to see if they contribute to a performance. But we need to wait and see what will be the reaction to the FIA on that."

Illustrations of the Lotus system show that the system uses hydraulic cylinders situated below the lower wishbones to adjust the ride height.

SOURCE: Autosport "

Well, so long as they promise not to use it in corners I guess it must be legal.

The old Suzuki motorcycle anti-dive simply blocked a compression damper bypass obviously increasing the compression damping - the brake fluid pressure blocked the bypass ...



"Suzuki's anti-dive system, developed from the feedback of racing technology, is now equipped on many of Suzuki's 1982 models. The new system is attached to the outer tube of the front fork. The brake line of the front brakes master cylinder leading to the caliper is connected by a hose to the antidive device. When the master cylinder's hydraulic line functions to brake the front wheel, it simultaneously operates the anti-dive device's plunger, which regulates and limits the flow of oil in the front fork. This reduces the compression of the front fork, which also reduces the extension of the rear shock absorber. Hence, the device serves to counteract the change in the motorcycle's attitude during braking." (from the Suzuki GSX 750/1000/1100 Supplementary Service Manual, Sept. 1981, p.6)

Also being discussed here .. http://forums.autosp...howtopic=159666

Since it can`t use driver input im thinking Some minor movement in the suspension to trigger some function.

as in the longitudinal direction,.

Edited by MatsNorway, 13 January 2012 - 11:11.

The concensus seems to be that it's illegal, but that, in itself, doesn't mean it will be banned in F1.

If it's simple to do and not expensive then no-one is going to gain from it.

Ban it; once it's accepted it will be developed to the nth degree until it steps over from acceptable to questionable, and then we'll be into mid-season reviews and interpretation issues again.

Edited by jatwarks, 13 January 2012 - 08:28.

The concensus seems to be that it's illegal, but that, in itself, doesn't mean it will be banned in F1.

If it's simple to do and not expensive then no-one is going to gain from it.

Ban it; once it's accepted it will be developed to the nth degree until it steps over from acceptable to questionable, and then we'll be into mid-season reviews and interpretation issues again.

I wonder if Mr Newey has known of this for sometime?

It's unclear to me how this system is designed to work but if hydraulic actuation is considered too "active" perhaps a simple mechanical anti-dive a la Udo Geitl http://vintagebmw.org/v7/node/8201 which feeds the braking torque from a floating caliper carrier into the sprung chassis through a linkage would be considered sufficiently passive. Not sure how the linkage would be accomplished in the tight packaging confines of an F1 car but it would I'd think hardly be more "active" than simple geometric anti-dive.

With road car suspension technology racing ahead of F1 practice, perhaps its time to reconsider the ban on active systems. Do we really want our "pinnacle of motorsport" limited to systems less sophisticated than those in common use on mass produced road cars? Anyone still remember when F1 tech was at least arguably state of the automotive art?

It's unclear to me how this system is designed to work but if hydraulic actuation is considered too "active" perhaps a simple mechanical anti-dive a la Udo Geitl http://vintagebmw.org/v7/node/8201 which feeds the braking torque from a floating caliper carrier into the sprung chassis through a linkage would be considered sufficiently passive. Not sure how the linkage would be accomplished in the tight packaging confines of an F1 car but it would I'd think hardly be more "active" than simple geometric anti-dive.

With road car suspension technology racing ahead of F1 practice, perhaps its time to reconsider the ban on active systems. Do we really want our "pinnacle of motorsport" limited to systems less sophisticated than those in common use on mass produced road cars? Anyone still remember when F1 tech was at least arguably state of the automotive art?

F1 might not match road car suspension for complexity electronically but completely exceeds it mechanically and hydrauliclly. The lotus system is crude compared to some of the systems of other teams.

The Rotus system is crude compared to some of the systems of other teams.

What "systems"? They have 2 wishbones and a damper/spring operated by a push/pullrod last time I looked....

I must admit to not keeping up with the rules, what have I missed?

F1 might not match road car suspension for complexity electronically but completely exceeds it mechanically and hydraulically.

Ummm, No? The complexity of design of modern road car suspensions and the tasks they have to perform is way beyond the simple tasks a F1 suspension does.

What "systems"? They have 2 wishbones and a damper/spring operated by a push/pullrod last time I looked....

I must admit to not keeping up with the rules, what have I missed?




Ummm, No? The complexity of design of modern road car suspensions and the tasks they have to perform is way beyond the simple tasks a F1 suspension does.

So in one sentence you admit to no knowledge of the current state of the art F1 inboard suspension systems, and the next you say they don't match the complexity of modern road car suspension? 'Damper/spring' doesn't come anywhere close.

btw I call it rude to quote me and then edit it to say something I didn't no matter how trivial the change.

So in one sentence you admit to no knowledge of the current state of the art F1 inboard suspension systems, and the next you say they don't match the complexity of modern road car suspension? 'Damper/spring' doesn't come anywhere close.

I knew I was being to polite....

F1 cars run dampers and spring - prove otherwise thanks.

The basic double Aarm suspension layout that a F1 car uses is no where near the complexity of, for example, a modern road car's 5 link layout, it doesn't need to be as it has no where near the performance parameters of a road car.

btw I call it rude to quote me and then edit it to say something I didn't no matter how trivial the change.

I also changed your bad spelling.

I was referring to 2012 rules that I haven't read in detail and was wondering by your statement if hydraulic additions had been allowed, they are not.

Ok, if I understand their system then the brake caliper is left to float and the brake force uses the caliper itself to operate a master cylinder that operates a slave cylinder at the bottom of the pushrod (the piston would be part of the the mount) extending the pushrod itself raising the ride height.

Let me draw you a picture ..

Very good! thats one way to do it.

Only problem is that you get no forces from the inner wheel if it lifts. But i guess it evens out.

One problem is that brake balance would affect this system. to even it out you need to do it at the back too. The problem then would be the long piping. (minor problem?)

The major problem would be to get those two systems to interact. without the front system interfering the rear.

The descriptions seem to be in line with Cheapracer's sketch and that is arguably legal unless you apply the rules very strictly.

I think the idea raises two interesting points

- firstly does it allow a skilled driver to "play" with turn-in by using a different braking pattern? Braking while you turn in will have a rather different effect ( good or bad) versus a car which doesn't load up the outside front with the extra load this system implies.

- Secondly the obvious advantage would seem to be th ability to set an overall lower ride height as braking dive won't use up front suspension travel. What the advantage is versus simple anti-dive I am not sure.

The concept of using a existing torque ( brakes in this case) to alter the suspension reminds me of something I have played with in my head of using engine torque to alter roll stiffness. In a car like a sprint car where the engine is mounted separately on the chassis you could interpose a hydraulic cylinder in one of the side engine mounts and the torque under acceleration would provide a hydraulic force to slide the anti-roll bar settings softer or harder.

Then you could optimise the roll stiffness for turn in and provide a different level of roll stiffness for traction out of the corners. So more roll stiffness at rear to enter and the rear stiffnes is reduced pro-rata to engine torque into the rear wheels to aid exit traction.

Just a thought, now where is Steve Kinser's phone number??

I find it a bit sad that the system still uses a brake calliper and disk to throw away energy as heat.
If the FIA were to develop regulation to encourage new technology ideas in F1, there would be no need for conventional brakes.
KERS systems would include energy recovery braking and modern ride height and variable handling set up would be electronic.

Ok, if I understand their system then the brake caliper is left to float and the brake force uses the caliper itself to operate a master cylinder that operates a slave cylinder at the bottom of the pushrod (the piston would be part of the the mount) extending the pushrod itself raising the ride height.

Let me draw you a picture ..

So you are proposing that the slave cylinder contains a fluid pressurised by the master cylinder? Sounds like a hydraulic system unless you are proposing that the working fluid is air - but 'hydraulic additions' according to you are not allowed - something of a contradiction?

Hydraulic systems within the suspension are perfectly legal as long as they are not externally powered, so the trick is to use power generated within the systems themselves to effect changes in behaviour / characteristic.

So you are proposing that the slave cylinder contains a fluid pressurised by the master cylinder? Sounds like a hydraulic system unless you are proposing that the working fluid is air - but 'hydraulic additions' according to you are not allowed - something of a contradiction?

Hydraulic systems within the suspension are perfectly legal as long as they are not externally powered, so the trick is to use power generated within the systems themselves to effect changes in behaviour / characteristic.

Not "THE" master cylinder, as in the the braking system one activated by the driver's foot. Rather "A" master cylinder activated by movement of the caliper bracket relative to the upright... so the hydraulics of the anti-dive system do not involve the hydraulics of the brake system. I'll be surprised if there is no complaining from the drivers about braking weirdness this season.

That would essentially be the same principle as the Udo Geitl system except using a passive unpowered hydraulics rather than a mechanical link which makes sense given the packaging constraints. Can't see that being ruled as illegal.

Not "THE" master cylinder, as in the the braking system one activated by the driver's foot. Rather "A" master cylinder activated by movement of the caliper bracket relative to the upright... so the hydraulics of the anti-dive system do not involve the hydraulics of the brake system. I'll be surprised if there is no complaining from the drivers about braking weirdness this season.

Yes I understand these are not part of the normal hydraulic braking system - Cheapy used the terms master and slave cylinders probably to spread fear and confusion! This setup must have negatives in terms of unsprung weight, brake cooling and probably upright stiffness - only two attachments may be used to secure the caliper to the upright (tech regs 11.2.2).

Why wouldn't the terms master and slave cylinder apply here? I don't see the two attachment rule making this impossible to implement.

Why wouldn't the terms master and slave cylinder apply here? I don't see the two attachment rule making this impossible to implement.

They do loosly apply but since elsewhere in the braking system these terms are commonplace the possibility of confusion arises - hence Engineguy's post. If you search a typical hydraulics glossary you will not find the terms master or slave.

No the two attachment rule doesn't make this impossible - just difficult to achieve given the package space constraints in this area.

Yes I understand these are not part of the normal hydraulic braking system - Cheapy used the terms master and slave cylinders probably to spread fear and confusion!......

Fair go! A master cylinder - be it brake, clutch, suspension or whatever, is simply any hydraulic cylinder where the initial hydraulic displacement occurs, and the slave cylinder (again be it brake clutch or suspension) is where the displaced fluid causes a consequent mechanical reaction.....

Edited by seldo, 16 January 2012 - 07:16.

I hope this stays in F1. Makes the need for having a silly stiff car less important. Just a little bit less.

It also makes it a bigger gain in having a lower CG.

I somehow envisioned it out at the damper mount. But it is ofc as cheapy sketched it up right next to the caliper. much lighter and more compact.

http://www.jamesalle...n-f1-explained/


BUT...

How about this??



Are the teams allowed to have bushings that move in the suspension?

I somehow envisioned it out at the damper mount. But it is ofc as cheapy sketched it up right next to the caliper. much lighter and more compact.

http://www.jamesalle...n-f1-explained/


BUT...

How about this??



Are the teams allowed to have bushings that move in the suspension?

Mats,

I think your idea is illegal due to this rule;

10.2.1 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.


The F1 regs can be found here:
fia tech regs

Mats,

I think your idea is illegal due to this rule;

10.2.1 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.


The F1 regs can be found here:
fia tech regs

I see now.. no fun to go around there.

Slight OT: But does this mean that they can`t have anti squat built into the suspension?

Edited by MatsNorway, 20 January 2012 - 14:24.

I see now.. no fun to go around there.

Slight OT: But does this mean that they can`t have anti squat built into the suspension?

Anti squat doesn't provide an additional degree of freedom, it's just a consequence of the wishbone geometry. Your proposal adds a new articulation to the wishbone mount.

As for bushings, I believe all the teams bolt the inboard wishbone ends directly to mountings on the monocoque using flexures — forget bushings, there isn't even a joint!

Anti squat doesn't provide an additional degree of freedom, it's just a consequence of the wishbone geometry. Your proposal adds a new articulation to the wishbone mount.

As for bushings, I believe all the teams bolt the inboard wishbone ends directly to mountings on the monocoque using flexures — forget bushings, there isn't even a joint!

So principally vertical is not vertical to the ground?

So principally vertical is not vertical to the ground?

Well, it's a single degree of freedom — I don't think they are concerned about the angle of the axis.


In other news, I heard via Scarbs' twitter today that on Peter Windsor's podcast Mark Gillan of Williams has confirmed that the FIA is banning these reactive systems via a technical directive. Sad. This is the FIA at its worst, maybe even dumber than the mass-damper-is-an-aero-device farce.

Well, it's a single degree of freedom — I don't think they are concerned about the angle of the axis.

Nice way of saying it. thank you.

In other news, I heard via Scarbs' twitter today that on Peter Windsor's podcast Mark Gillan of Williams has confirmed that the FIA is banning these reactive systems via a technical directive. Sad. This is the FIA at its worst, maybe even dumber than the mass-damper-is-an-aero-device farce.

Thats horrible. this device would possibly made a stiff car less important in relation to the aero...

Thats horrible. this device would possibly made a stiff car less important in relation to the aero...

The wheelbase is so long, and the CoG so low... even at the high-G braking they attain I wouldn't think the dive force would be anywhere near the magnitude of aero downforce... so they still would be stiff. Granted in such a competitive setting, a millimeter less dive may improve aero df stability enough to be worthwhile IF you're the only team that has it. From a spectator standpoint, I think it's better to let the fan see a little bit chassis reaction in the car (as little as it may be these days). Even very small visual clues that the car and the driver are actually doing something more than a slot car are important IMHO. Amazing as it may be, we don't want this... Insane fast... insanly boring

Amazing as it may be, we don't want this... Insane fast... insanly boring

That's screwed up.

I don't understand why it has taken so long to ban it. If a driver puts his foot on the brake pedal and it activates a system to adjust the ride height advantageously it is a driver activated aero system, not purely about suspension geometry. For instance, the concept of trail braking could take on a new meaning if the car is designed around the driver being able to adjust the suspension characteristics.

Steve

I don't understand why it has taken so long to ban it. If a driver puts his foot on the brake pedal and it activates a system to adjust the ride height advantageously it is a driver activated aero system

Steve

Its not a Aero device pr definition. But its usage gives gain in that area.

we don't want this... Insane fast... insanly boring

What's the point?

Now here's something worthwhile ...

If the sole purpose of a device is to help aerodynamics, I'm actually not sure what else to call it. Calling it a ride-height leveler or reactive ride height or whatever is dancing around the fact that the ride height is far more important to aerodynamics than anything else on modern F1 cars. They're not playing with the ride height to avoid bottoming out here. The device is moving parts to aid aerodynamics; i.e. a movable aerodynamic device.

... at least that's what I'm going to argue today ... whether it's good or bad for the sport ...

If the sole purpose of a device is to help aerodynamics, I'm actually not sure what else to call it. Calling it a ride-height leveler or reactive ride height or whatever is dancing around the fact that the ride height is far more important to aerodynamics than anything else on modern F1 cars. They're not playing with the ride height to avoid bottoming out here. The device is moving parts to aid aerodynamics; i.e. a movable aerodynamic device.

... at least that's what I'm going to argue today ... whether it's good or bad for the sport ...

I think you are correct.
It is a shame and has been now for a long time, that there seems to be no formula that allows a meaningful and open platform for technical development.
How about a one lap formula.
Safety regulations of course but anything else you want to attempt one fast lap.
Do it at F1 meetings to spice up the action.
It would allow in all new technology.

Its not a Aero device pr definition. But its usage gives gain in that area.

Yes, but how long would it be before a 'clutch' (or some other perfect way to describe it) was added to the braking system (if not already), allowing the braking effort to be channelled longer while the driver was on the throttle ready for the next straight? It would not only allow for the ride height to be maintained into the corner, but through it and out of it, all via a driver operated pedal.

Steve

I am tired of all this banning. Every time someone has a clever idea it gets banned.
Worse, first FIA gives the green light and make the team spend effort on it and then oops, banned.
Colin Chapman is probably doing backflips in his grave.

Backflips are banned.

Backflips are banned.

So Chapman will put a mask on the back of his head, claim he has two faces, so either way he flips is a front flip, and the ban does not explicitly mention front flips, so it is legal.

Backflips are banned.

Will the FIA penalise itself when it changes its mind again on something else?

As this system was just another smarty-pants way to manipulate the unique aero properties of the modern grand prix car, I shall not shed a tear, for it has little relevance in the real world. If grand prix cars all had 100mm of ground clearance, none of this ground-effect aero nonsense would be an issue anyhow.

Edited by JJW, 24 January 2012 - 03:16.

As this system was just another smarty-pants way to manipulate the unique aero properties of the modern grand prix car, I shall not shed a tear, for it has little relevance in the real world.

Actually it has potential for anti dive while maintaining compliant suspension for higher class cars (cost prohibitive for lower market cars).

One of the issues of anti-dive through geometry is, as Greg fondly refers to it, they are "anti-suspension".

This concept has been around a while in one form or another, wouldn't the car guys already have used it if it had much upside potential for road cars? Does some dive perhaps help the driver as feedback to gauge his decel perhaps as long as there's enough wheel travel left for the suspension to work? I can't remember ever being bothered by dive under braking in a street car.

I can't remember ever being bothered by dive under braking in a street car.

There's the nub. However in a car with a high cgz/wheelbase ratio you can run out of antidive - it feels as if it is standing on its nose. The tradeoff is with impact harshness,geometrical a/d tends to reduce wheel recession in jounce, which is a bad thing for impact harshness

Actually it has potential for anti dive while maintaining compliant suspension for higher class cars (cost prohibitive for lower market cars).

One of the issues of anti-dive through geometry is, as Greg fondly refers to it, they are "anti-suspension".

this.

It is a possible way to be able to run more correct low speed suspension setup. without the penalties under higher speeds.

One track this could be nice on is Monaco out of the tunnel. Really bumpy area where the cars are stiffly sprung.