20 replies to this topic

[perfectelise]

If all teams build underweight and use ballast then why not use movable ballast. Towards teh back for starts to aid traction, to the left for left hand corners etc.
I once heard of an idea to pump mercury (toxic pollution in a crash) around to get this effect.
Any ideas for a workable system?

perfectelise

[Ali_G]

That really is the problem. Mercury really is the most suitable material to use in a ballast control system. But there is no way that the FIA would allow it.

Solids weights just wouldn't be accurate enough.

Anyone else know a very dense liquid which is isn't Mercury.

Niall

[Ursus]

Moveable ballast is an excelent idea but ufortunatly the ballast must be fixed in the car.

IIRC teams in the old DTM series used moveable ballast though I can't say wether it was mercury or not.

[Ali_G]

Ursus: What about tiny ball bearings inside the car. Easy to move around and if they were enclosed properly they wouldn't be too haserdous in a crash.

I never thought that such a complicated system was used in Touring Cars.

Niall

[Ursus]

Even though the regs doesn't specificly says that the ballast can't be moveable it has to be secured so it only can be loosened with the use of tools. It is very unlikely that moveable ballast would pass the scrutineering.

[perfectelise]

What about a machined disc with vertical axis of rotation. If it was asymetrical then by rotating the disc one way or teh other you could move it's centre of gravity forwards/backwards, left/right. So long as the mechanism was strong then teh ballast would 'securly fixed'.

perfectelise

[Ali_G]

Yes but stisting the disc would take valuable power away from the Engine. Also twisting the disc would create stability problems.

Niall

[perfectelise]

The engine has an excess of power during starts and cornering.
Perhaps the torque reaction from turning the disc would help turn the car into a corner?

perfectelise

[Ali_G]

Afraid not. All the turning disk would do is either cancel oversteer or understeer if it were perfect. If it isn't it would do the opposite.

niall

[desmo]

Racecar Engineering, I believe, reported that at least one F1 team had tried the concept (mercury ballast) which appaently wasused in the DTM.

[Yelnats]

Yes Desmo, I read that article also. I should think the mercury could be replaced with some form of harmless metal slurry if the toxicity of Mercury was a problem. The BTC is a special case where the front wheel drive cars were at a terrifc disadvantage during the starts so weight disribution was a bigger issue there. F1 cars are far more ideally setup and balanced with RWD and I should think the benifits would be significantly less than the complications introduced.

[just me again]

The moveable ballast in DTM cars was "normal" metal ballast placed on a sledge there could move forward/backwards. I think the main reason was to prevent wheelspin ( the 2WD mercedes cars had a disadvantage against the 4WD opel and alfa's. ).

[PAD]

I like (AliG's) idea of ball bearings. If they were placed inside a enclosed tube which ran most of the length of the car then the "ballast" - which comprises of the tube with its contents - could only be removed with the aid of tools.

As the car accelerated the ball bearings would move towards the back of the car, and under braking towards the front. Obviously this is the same principle as the DTM cars described but is contained.

I think this is a similar idea to that used in some baseball bats where a liquid (water?) sits inthe handle end when the bat is held upright in preparation for the shot, and is "thrown" to the outer end just as the ball is struck. This gives an initial centre of gravity near the handle for fast acceleration and change of direction, followed by a CoG nearer the end of the bat resulting in an apparent heavier bat for striking the ball.

[Ali_G]

PAD: Thanks a lot. The only problem is that in the event of a crash flying ball bearings could be dangersous. But some sort of protective covering should be enough.

A lot more safer than Mercury though.

Niall

[MacFan]

CART cars use weight jackers to move ballast around while the car is moving, so presumably there is an advantage if the regulations allow it.

[Bluehair]

With the ball bearing solution, I think a spring or other device would be needed at the front and rear of the tube. Imagine braking at the limit of adhesion while the ballast is still moving forward. Then when the ballast gets to end of the tube, the driver feels as though he has been rear-ended and the car would slide. The same effect would occur during acceleration. Without some fast acting traction control, the tires would spin as the ballast slams into the aft end of the tube. If this effect could be cushioned however, I think it may be somewhat beneficial.

[desmo]

Actually for braking AND acceleration a rearward weight bias is generally preferred. Ask any Porsche afficianado.

[blkirk]

Rear weight bias does make turning a bit tricky, however. Old 911s have trailing throttle oversteer of legendary proportions.

[Paolo]

Yeeeaaah ! And that's how ALL cars should handle !
Hurra' for the old 911 !

[Yelnats]

The weight jackers in CART, to my understanding, don't move weight around but instead place more or less weight on a tire by jacking the suspension down or up. These devices are invaluable in oval races where all corners are more or less the same. In road racing their effect is much more unpredictable due to the varied nature of the turns so they are less usefull there.

[Ali_G]

Yelnats: Would that be a form of Active Suspension. ALso banned by the FIA.

Niall