304 replies to this topic

[Timstr11]

Renault has reportedly placed springed balast in the nose cone which counter balances vertical movement, thus decreasing pitch sensitivity.
Very clever!

See illustration:
http://www.formula1....article_291.jpg

Another illustration which makes more sense to me (balast moving between two springs).

Is this not movable balast?

[KWSN - DSM]

No it is not.

Rrmour has it that Ferrari, Honda and McLaren have similar systems either intesting or actually in place. Can not be long before all teams have it.

[rhm]

How is it not moveable ballast? It's unnecessary weight that moves about in the car. Sounds like moveable ballast to me.

Obviously the scrutineers don't think it's moveable ballast otherwise they wouldn't have passed the cars with it in, but I'd like to know what their reasoning is.

[LMP900]

In a thread about 20 months or so ago, I suggested using ballast as inertial damping, on the mythical Atlas F1 car. It's nice to see that we lead the field technologically!

[Timstr11]

ARTICLE 4 : WEIGHT

4.2 Ballast :
Ballast can be used provided it is secured in such a way that tools are required for its removal. It must be
possible to fix seals if deemed necessary by the FIA technical delegate.
***************************

Legit according to the rules.

[rhm]

Originally posted by Timstr11
ARTICLE 4 : WEIGHT

4.2 Ballast :
Ballast can be used provided it is secured in such a way that tools are required for its removal. It must be
possible to fix seals if deemed necessary by the FIA technical delegate.
***************************

Legit according to the rules.

Wow, I just checked the regs myself and you're right. This ban on "moveable ballast" is a myth, there isn't anything in the rules that forbids it. It says that you must need tools to remove it, but that would still allow you to, for example, have weights slide back and forth on linear bearings in the floor of the sidepods driven by hydraulics.

[LMP900]

Two more points. Firstly, it's not ballast - it's a functional part, an inertial damper. The ballast regs don't apply. Secondly, I trust the teams are trying something similar in the front wing endplates or similar to increase the roll inertia on some circuits.

[WHITE]

Originally posted by rhm


Wow, I just checked the regs myself and you're right. This ban on "moveable ballast" is a myth, there isn't anything in the rules that forbids it. It says that you must need tools to remove it, but that would still allow you to, for example, have weights slide back and forth on linear bearings in the floor of the sidepods driven by hydraulics.

Why not using the driver himself as a "movable ballast" ? Is is only a question of having him seating on a seat susceptible of sliding back and forth on linear bearings in the floor and driven by hydraulics

[Timstr11]

Originally posted by WHITE



Why not using the driver himself as a "movable ballast" ? Is is only a question of having him seating on a seat susceptible of sliding back and forth on linear bearings in the floor and driven by hydraulics

Yes, but the driver is near the center of gravity and would thus be less effective

[rhm]

Originally posted by WHITE
Why not using the driver himself as a "movable ballast" ? Is is only a question of having him seating on a seat susceptible of sliding back and forth on linear bearings in the floor and driven by hydraulics

I suspect you're not serious, but really there's no scope for moving the driver. The seat back has to be entirely forward of the fuel cell and the feet have to be rearward of the front wheel axel-line.

[desmo]

So this sprung mass device would be similar in theory to those tuned mass dampers that are used in architectural applications? It sounds like in the description its actual application is perhaps to address a specific tire or chassis mode. Is there precedent for something similar to this in pneumatically tired vehicles?

[Greg Locock]

Yes, absolutely. We fit a 200-300 kg mass that has other functions and then tune the hydraulically damped suspension of that mass so as to interact correctly with the primary and secondary ride characteristics of the vehicle. Typically we can get a subjective 1.5 VER improvement, which might equate to 6 dB, or a halving of inputs at specific frequencies.

Now, fair enough, we don't tune the vertical modes to improve traction, but we certainly are aware of the interaction between torsional modes of the driveline, which are heavily dependent on the inertia of the engine and the rates of the engine mounts, and 'axle tramp'. There's also a mode, trailer hitching, which is a more benign form of axle tramp. Solving those torsional modes is tricky as the forces involved are enormous compared with the usual vibration problems.

Somewhat related is the use of tuned mass absorbers in BMW convertibles. They used a 25 kg slug of cast iron to suppress 'scuttle shake'. I can't remember whether it was compliantly mounted or just bolted in. Long before then, Rover used to individually tune an absorber on every car, in the late 60s early seventies.

[LMP900]

Originally posted by Greg Locock
[B]Yes, absolutely. We fit a 200-300 kg mass that has other functions and then tune the hydraulically damped suspension of that mass so as to interact correctly with the primary and secondary ride characteristics of the vehicle. Typically we can get a subjective 1.5 VER improvement, which might equate to 6 dB, or a halving of inputs at specific frequencies.

This would be the engine, as you mentioned in the earlier thread? The idea of using ballast as inertial damping occurred to me when we were testing an F3 car on 4-post rig (this was before the days of "post inflation" - four was all we could find). The airbox, which was a very light carbon moulding containing only an air filter, was at that time fitted to the inlet tract with a flexible coupling, and the stiffness of the coupling had a noticeable effect on the contact patch forces at certain frequencies

[zac510]

I've heard a rumour that Toyota have tested a damper like this but in a side-to-side (lateral) configuration. Does this sound viable or is it a chinese whisper rumour that should be buried right now?

[LMP900]

Lateral compliance would affect the roll mode, but I think that vertical compliance of masses disposed laterally (e.g. the FWEP ballast I suggested earlier) would be more effective at this. Lateral compliance would also affect the transient response, which may be useful, but any lateral displacement of a substantial mass would result in unfavourable CG movement.

[Ben]

Apart from the OP no one's been talking specifically about the effect on pitch sensitivity of having the inertial damper in the nose as opposed to centrally. I can't imagine they'd increase the yaw inertia (and CG height given the raised nose) if the longitudinal offset from the CG was important

Anything I've read about rig testing talks about minimising pitch mode disturbance as one of the most important things to target.

Ben

[Greg Locock]

I was just thinking about what happens when we get it wrong, and tune the engine bounce or pitch mode to wheelhop.

Yup, definitely affects traction!

[LMP900]

Originally posted by Ben
Apart from the OP no one's been talking specifically about the effect on pitch sensitivity of having the inertial damper in the nose as opposed to centrally. I can't imagine they'd increase the yaw inertia (and CG height given the raised nose) if the longitudinal offset from the CG was important

Anything I've read about rig testing talks about minimising pitch mode disturbance as one of the most important things to target.

Ben

You're right - it's another means of tuning pitch response. But IMO roll and warp are at least as important in terms of maximising grip.

The shift of emphasis from low yaw inertia and low CG height to optimum longitudinal CG position and more creative use of ballast has led to compromises (such as the present example) which wouldn't have been considered a few years ago. I'm told the Toyota nose weighs 75kg and is filled with Densamet balls.

[Ross Stonefeld]

When you say nose, do you mean the front end of the monocoque? Because a 75kg front wing/nose bit would be a bit hard to change in a pitstop

[LMP900]

Nosecone and wing.

They presumably use spheres rather than monolithic ballast to make it buckshot rather than armour-piercing ordnance....

[Christiaan]

My understanding all these years was that the ballast material was supplied by FIA. In which case I would have thought that even if they had a ban on moveable ballast that if you opted to use your own ball bearings instead of theirs then the rules wouldn't necessairly apply. The other thing is that incorporating suspension and ballast to me sound intuitive. While I am on that I have always wondered if there is any benefit to making the wheel rims as heavy as possible with a view to improve the car's weight distribution and manage the roll tendancy.

[LMP900]

As I said earlier, an inertial damper is not ballast, so the ballast rules don't apply.

Regarding increasing the unsprung weight... well IIRC Citroen did it with inertia dampers on the 2CV. But to do so by increasing the rim weight would be negative on all fronts - CG height, rotating inertia, gyroscopic effects as well as the inertial effects on tyre contact patch loads, without any prospect of using it as a damper.

[rhm]

Originally posted by LMP900
As I said earlier, an inertial damper is not ballast, so the ballast rules don't apply.

I'd say that's a matter of opinion since the regulations don't offer a definition of "ballast".

It is commonly held to be a mass added to the car with no purpose other than to increase the weight. From that you could argue that because this device performs another function that is isn't ballast, but that function is solely to allow an otherwise functionless lump of tungsten to move about.

It could all become accademic if the FIA were to introduce a maximum weight limit for nosecones as they were threatening to last season.

[Ross Stonefeld]

Wouldnt all dampers be moveable ballast then?

[LMP900]

Originally posted by rhm


I'd say that's a matter of opinion since the regulations don't offer a definition of "ballast".

It is commonly held to be a mass added to the car with no purpose other than to increase the weight. From that you could argue that because this device performs another function that is isn't ballast, but that function is solely to allow an otherwise functionless lump of tungsten to move about.

...in the same way as a brake disc is an otherwise functionless lump of carbon? Sorry, your logic seems flawed to me. If any part has a function other than to increase car weight, it's not ballast.

Of course the FIA could rule it out, as they could any other development, but fortunately the teams don't let that deter them.

[rhm]

It's not a matter of logic, it's a matter of opinion like I said. The regulations don't offer a definition of ballast, I was just positing one, the one that you are probably assuming.

The lump of carbon we call a brake disc has an obvious function and so does virtually everything else on the car. Since the lump of tungsten in the "inertial damper" is just a mass that increases the weight of the car it could still be called ballast. OK, so they've mounted it on springs so it can change the car's CoG as well as increase it's weight, but that lump of tungsten is still just a mass. If the sum of the parts has a greater function then it's because of the springs, not the mass. Therefore the decision would come down to whether they regard the "inertial damper" as a complete unit or just ballast on springs.

FWIW I don't really care whether it's allowed or not. Since the rules don't apparently outlaw mounting ballast on springs, or even on any type of mechanical device as far as I can tell, it's moot anyway. I just don't think you can say it is definitely not ballast because it's not defined in the rules and as I hope I've demonstrated, the situation could be interpreted more than one way.

[Fat Boy]

On a side note. The really cool DTM cars of a couple years ago had a mass that could be ran fore/aft in the car on a jack screw. In the rulebook, ballast was defined as being rigidly bolted to the chassis. Because of this, the moveable ballast was determined to be part of the suspension and therefore allowed.

Further aside. When doing rig testing on a car we wanted to remove a part of the bodywork to allow for easier access to the dampers/springs. The problem was that the road profile would excite various parts of the bodywork that were now free to move which made our contact patch disturbance numbers go to hell. We had to run all the bodywork to get any reasonable numbers. If moving bodywork can make grip go to hell, then my guess is a properly sized and engineered inertial damper can help things out. Just a guess.

[Ross Stonefeld]

How many tenths you reckon are in leaning your head to the inside as much as possible mid corner?

[Fat Boy]

From a CG point of view, I'd say nothing. In terms of the whole car, it's just miniscule. You're talking about maybe a pound or 2 swing.

In terms of screwing up your line of vision, I'd say it has to hurt. Overall, I'd say it's probably a net loss.

[hyperbolica]

Originally posted by Ross Stonefeld
How many tenths you reckon are in leaning your head to the inside as much as possible mid corner?

If it looks cool enough, it might attract some sponsor money, which might in turn by you a tenth or two.

[desmo]

By rhm's reasoning, wouldn't crankshaft counterweights be a movable ballast as well?

[rhm]

Originally posted by desmo
By rhm's reasoning, wouldn't crankshaft counterweights be a movable ballast as well?

*sigh* No, because (a) they're pretty important to the function of the engine and (b), they wouldn't really work if they were rigidy attached to the block.

[J. Edlund]

Originally posted by rhm


*sigh* No, because (a) they're pretty important to the function of the engine and (b), they wouldn't really work if they were rigidy attached to the block.

The counterweights on the crankshaft perform a function just like an inertial damper in the nose cone. Inertial dampers may also be used in the engine to reduce torsional vibrations. To make the components as small as possible a high density allow is usually used.

The counterweights on the crankshaft are usually made out of a tungsten alloy (and are separate from the rest of the crankshaft), they would not perform their function if they were attached to the chassi, but that is also the case with the inertial damper in the nose cone, if we attached the high density mass directly in the nose cone it would not perform the function intended. So it's not ballast, it's a damper and is no different from the mass added to a torional vibration damper or crankshaft counterweights.

[Christiaan]

when I was a kid I thought up a car that had a heavy block on the chassis floor that moved longitudinally to absorb impact in the vent of an accident. OK, I was probably like 12, however I wonder if you could have an active dense block in a car that moves in two axis on the floor board to actively move the car's CG in accordance with the driving conditions. While it will not be possible in an F1 car because of space, would it be legal? Would there be any benefits?

[Ben]

Originally posted by rhm


*sigh* No, because (a) they're pretty important to the function of the engine and (b), they wouldn't really work if they were rigidy attached to the block.

And an inertial damper is pretty important to the attitude control of the car if you choose to use one. Just because the cars don't traditionally have them doesn't make them unecessary ballast.

Ben

[WHITE]

Originally posted by Christiaan
OK, I was probably like 12, however I wonder if you could have an active dense block in a car that moves in two axis on the floor board to actively move the car's CG in accordance with the driving conditions. While it will not be possible in an F1 car because of space, would it be legal? Would there be any benefits?

This is what I had in mind when talking about using the driver himself as a movable ballast. Is not it what a motobiker does ?

[rhm]

Originally posted by J. Edlund


The counterweights on the crankshaft perform a function just like an inertial damper in the nose cone. Inertial dampers may also be used in the engine to reduce torsional vibrations. To make the components as small as possible a high density allow is usually used.

The counterweights on the crankshaft are usually made out of a tungsten alloy (and are separate from the rest of the crankshaft), they would not perform their function if they were attached to the chassi, but that is also the case with the inertial damper in the nose cone, if we attached the high density mass directly in the nose cone it would not perform the function intended. So it's not ballast, it's a damper and is no different from the mass added to a torional vibration damper or crankshaft counterweights.

If you took a crankshaft counterweight and rigidly attached it to the block, they wouldn't be crankshaft counterweights anymore, yes? They wouldn't even be useful ballast because the job of the engine designer is usually to make the engine as light as possible.

OTOH, the ballast in the middle of the "inertial damper" would still be ballast if it was rigidly attached to the chassis. You are assuming that the "innertial damper" is a single unit, akin to any other major component on the car, and that the heavy lump of metal in it isn't ballast, and then expecting me to prove that that lump *is* ballast. The point being, the FIA _could_ regard a heavy lump of metal to be ballast if they wanted to since there is not definition of ballast in the regulations!

jeez, what amazes me about this thread is that one person starts by making a blanket statement "It's not ballast, it's an inertial damper" without offering any justification at all for that position, then when I try and point out that the FIA could easilly take a different view, everyone just wants to pick holes, not even in my main point, but in examples or side-issues. What a waste of time. I should have just posted "it's a matter of opinion" and been done with it.

[Ben]

Originally posted by rhm
How is it not moveable ballast? It's unnecessary weight that moves about in the car. Sounds like moveable ballast to me.

Obviously the scrutineers don't think it's moveable ballast otherwise they wouldn't have passed the cars with it in, but I'd like to know what their reasoning is.

If there's no definition of ballast in the regs then your definition of "unnecessary weight" is just an interpretation. Your definition of "necessary" seems to be related to how common the component is. Pitch springs didn't exist much before the early 90s they're now common place why is this any different?

Clearly the FIA do not consider it ballast or they'd have banned it. Whether they subsequently change their mind is another matter.

Ben

[WHITE]

First of all, excuse me my ignorance, but from the moment ballast is used to balance the car, is not this a function itself ? By doing this, ballast is no longer a weight put at randon just to comply with the minimum weight rule and therefore, it is not ballast anymore. So, could we conclude that there is no ballast ?

[Halfwitt]

Just to fan the flames, I don't believe it is ballast. If I were designing some ballast, I'd screw it to the chassis. Cheap, simple, no fuss, reliable.

It's a damper. It's just causing some fuss because it isn't damping the motion of the wheels. Some people here even think they know what it is used for, and make sensible points to this effect.

Let's face facts, we're clever enough to know that if we were designing real mobile ballast, we'd design something a bit more sophisticated than a bit of metal wedged between two springs bobbing hopelessly up and down on the nose of the car. Wouldn't we choose to alter the front to rear weight bias in real time depending on what the car is doing? I would. So would most of you.

Please feel free to argue, and also to be abusive.

[Tooheavy]

An obvious way to apply such an "inertial damper" would be to have as large a mass as possible (100kg+ ballast in F1 currently?) in a tube the length of the chassis. Under normal cornering conditions it is at it's maximum forward point and the car is balanced, but when accelerating (not braking) it moves to the back to get as much weight as possible over the drive wheels and also reduce the initial mass to accelerate. Might be good for a few places off the grid.

At the end of a straight when the mass is at the back of the car it would allow you to brake fractionally later if the mass were allowed to slide forward during the braking (effectively briefly reducing the mass to decelerate).

The same thing could possibly also be done with the fuel by having a longitudinally extended fuel cell.

[hyperbolica]

I think one could define ballast as a removable lump of mass with no other purpose or effect than to relocate CoG to a desired position, and/or to produce desirable moments of inertia. (Compare the use of ballast in racing yachts.)

Inertial dampers and counterweights have insignificant effects on CoG and moments of inertia, and have other purposes too.

[Powersteer]

Clever stuff, should be very effective in slow speed corners while going over the curbs controlling the tyres bouce.

[Timstr11]

Now the FIA has banned it with a creative rules interpretation, labeling it a moveable aerodynamic device.

If I was Renault, i'd take the FIA to court.

[WHITE]

Originally posted by Timstr11
Now the FIA has banned it with a creative rules interpretation, labeling it a moveable aerodynamic device.

And flexible wings do not move "enough" as to be aerodinamic devices :

[LMP900]

Yes, it stretches the FIA's credibility rather, doesn't it? Not that they have to worry about what anyone thinks of them.... Given this "clarification", how is it that a conventional heave spring/damper isn't also a moveable aerodynamic device? Or an anti-roll bar?

It also helps Ferrari and hurts Michelin. but that may be just coincidence of course.

[Dragonfly]

Pure coincidence, honestly
Though I'm curious to know who exactly pointed the finger, assuming those who use it already are not interested in banning.

[Timstr11]

Although now reading the alleged rule, there is room to read it in different ways.

*******************************
3.15 Aerodynamic influence :
With the exception of the cover described in Article 6.5.2 (when used in the pit lane) and the ducts
described in Article 11.4, any specific part of the car influencing its aerodynamic performance :
- Must comply with the rules relating to bodywork.
- Must be rigidly secured to the entirely sprung part of the car (rigidly secured means not having any
degree of freedom).
- Must remain immobile in relation to the sprung part of the car.
Any device or construction that is designed to bridge the gap between the sprung part of the car and the
ground is prohibited under all circumstances.
2008 F1 Technical Regulations 13 / 53 21st December 2005
No part having an aerodynamic influence and no part of the bodywork, with the exception of the skid block
in 3.13 above, may under any circumstances be located below the reference plane.

[desmo]

There is clearly nothing in the rule cited that in any way prohibits the sprung mass damper devices. Whomever so opined is either an idiot or takes us to be idiots.

[Dieoff]

FIA said that the Damper System in Ilegal!

http://www.autosport...rt.php/id/53298

The rule changes will have any noticeable effect on the performance of the cars?