Red Bull RB18

[Big Tea]

The COG and weight distribution are not the same thing, the COG is a calculated point that will balance the car. The weight distribution is calculated by corner weights.

The location of the c.g. (actually center of mass) determines the weight distribution on the front/rear. For example, consider a car with a wheel base of 100 whatevers and a mass of 100 whatevers. If the c.g. is at 50 the car would balance on a knife edge at 50. The fore/aft weights would be 50/50. If the c.g. was moved so it was over the rear axle (this is of course imaginary for simplicity sake) the c.g. would be at 0 and the rear weight 100; the front weight would be 0. Move the c.g. to 45 and the rear weight would be 55, the front 45, which is what the regulations require ±. Now how do you change the fore/aft weights without moving the c.g. or vice versa? You can't. This is pretty basic stuff.....

To clarify whether the regulations apply during the entire meeting, here is Article 2 of the Sporting Regulations...

2) GENERAL UNDERTAKING
2.1 All drivers, Competitors and officials participating in the Championship undertake, on
behalf of themselves, their employees, agents and suppliers, to observe all the
provisions as supplemented or amended of the International Sporting Code (the Code),
the Formula One Technical Regulations (Technical Regulations), the Formula One
Financial Regulations (Financial Regulations) and the present Formula One Sporting
Regulations together referred to as “the Regulations”.
2.2 The Championship and each of its Events is governed by the FIA in accordance with the
Regulations.
2.3 Event means any event entered into the FIA Formula One Championship Calendar for
any year commencing four (4) hours before P1 is scheduled to start and ending at the
time for the lodging of a protest under the terms of the Code or the time when a technical
or sporting certification has been carried out under the terms of the Code, whichever is
the later.

Reading your post made me think. You mention weight over the rear axle. (and under roll hoop for lifting)
Am I right in thinking that anywhere along from behind the centreline, until it starts giving the seesaw effect past the axle, the weight is going to be the same on a scale (statically) but not dynamically?

So will 20kg over the axle centre point be the same on the scale as 20 kg half a metre further forward?
It certainly will not be the same on a bend will it?

[vorticism]

The spec weight distribution is considered as a factor of total minimum dry weight. This means the weight distribution with fuel and driver is not regulated. That's how I read it.

That being the case, it would be possible to alter fuel mass centers.

-Mass center(s) shifting as fuel is consumed
-Mass center(s) shifting during pitch, heave, yaw, and lateral acceleration

Fuel mass may be the last frontier as it relates to mass dampening.

Given that only RB is struggling with fueling issues while struggling the least with porpoising, we might speculate that they are using the fuel tank as a means to quell porpoising, in addition to their aero or suspension design.

Such systems may have compatibility issues with the evaporative nature of ethanol.

A tuned liquid damper (TLD) is a device which absorbs energy of structural vibration through sloshing of fluid when sloshing frequency is tuned to the structural frequency. TLD is widely used to control wind-induced vibrations in civil structures.

f.e. a horizontal plate or mesh would provide vertical resistance to a vertically accelerating fuel mass.

[AR3-GP]

I highly doubt it. I don't think RB are using fuel to combat porpoising because the car doesn't porpoise during qualifying on low fuel. It's hardly a "tuned" mass damper when its mass is reducing throughout the race. Also, such a solution requires energy dissipation which will heat up the fuel.

At most, there are baffles in the tank to prevent sloshing of the fuel which causes deleterious handling effects.

[vorticism]

Heating of the fuel is one of the reasons I bring it up. Excessive vaporization leading to some of their fueling issues. By some unknown mechanism.

We don't know how much fuel they carry in quali. We don't know the fuel volume of such a speculative system.

[godlameroso]

The COG and weight distribution are not the same thing, the COG is a calculated point that will balance the car. The weight distribution is calculated by corner weights.

The location of the c.g. (actually center of mass) determines the weight distribution on the front/rear. For example, consider a car with a wheel base of 100 whatevers and a mass of 100 whatevers. If the c.g. is at 50 the car would balance on a knife edge at 50. The fore/aft weights would be 50/50. If the c.g. was moved so it was over the rear axle (this is of course imaginary for simplicity sake) the c.g. would be at 0 and the rear weight 100; the front weight would be 0. Move the c.g. to 45 and the rear weight would be 55, the front 45, which is what the regulations require ±. Now how do you change the fore/aft weights without moving the c.g. or vice versa? You can't. This is pretty basic stuff.....

To clarify whether the regulations apply during the entire meeting, here is Article 2 of the Sporting Regulations...

2) GENERAL UNDERTAKING
2.1 All drivers, Competitors and officials participating in the Championship undertake, on
behalf of themselves, their employees, agents and suppliers, to observe all the
provisions as supplemented or amended of the International Sporting Code (the Code),
the Formula One Technical Regulations (Technical Regulations), the Formula One
Financial Regulations (Financial Regulations) and the present Formula One Sporting
Regulations together referred to as “the Regulations”.
2.2 The Championship and each of its Events is governed by the FIA in accordance with the
Regulations.
2.3 Event means any event entered into the FIA Formula One Championship Calendar for
any year commencing four (4) hours before P1 is scheduled to start and ending at the
time for the lodging of a protest under the terms of the Code or the time when a technical
or sporting certification has been carried out under the terms of the Code, whichever is
the later.

You raise and lower weight and it will change COG despite equal weight distribution, cars are not flat 1 dimensional lines. If it's hard to visualize past 2 dimensions, the hypotenuse of a triangle is longer than the base, by raising weight relative to a reference plane creates a bigger lever arm on the car's natural fulcrum moving the COG forward.

[AR3-GP]

Heating of the fuel is one of the reasons I bring it up. Excessive vaporization leading to some of their fueling issues. By some unknown mechanism.

We don't know how much fuel they carry in quali. We don't know the fuel volume of such a speculative system.

For what it's worth, the issue in Australia was a fuel line leak.

[godlameroso]

Also, weight distribution is measured on corner weights, not a knife edge. Each tire is weighed, then the weights are tallied up. Front axle has to weigh ~5% less than the rear, that's all, COG can be changed because as far as the corner scales are concerned, the COG is the tire contact patch.

[AR3-GP]

Also, weight distribution is measured on corner weights, not a knife edge. Each tire is weighed, then the weights are tallied up. Front axle has to weigh ~5% less than the rear, that's all, COG can be changed because as far as the corner scales are concerned, the COG is the tire contact patch.

The "corner weight" is a direct function of the X-distance between the CoG and the resultant force (pressure*area) at the tire contact patch. "Axles" don't matter. As soon as the CoG moves in the x-dimension, the weight distribution measured at the contact patch changes.

[vorticism]

Front axle has to weigh ~5% less than the rear, that's all

The rule said another way is: the front axle must never weigh less than 354 kg, and the rear axle must never weigh less than 429 kg. Additional weight per axle is unregulated.

[Andi76]

Sky Germany just reported that the "fluid" Verstappen mentioned was FUEL. They did not say where this information comes from, but they are well informed usually. So Verstappens car seemed to have a fuel-leak. The problem probably was the fuel line that connects the fuel tank with the high pressure pump on top of the engine, which takes the fuel pressure for the direct injection system.
The word is that E10 damages this fuel line.

[AR3-GP]

Sky Germany just reported that the "fluid" Verstappen mentioned was FUEL. They did not say where this information comes from, but they are well informed usually. So Verstappens car seemed to have a fuel-leak. The problem probably was the fuel line that connects the fuel tank with the high pressure pump on top of the engine, which takes the fuel pressure for the direct injection system.

Yes, Amus has reported that Red Bull engineers detected an abnormal loss of fuel in the telemetry and told him to stop.

[Rodak]

Front axle has to weigh ~5% less than the rear, that's all

The rule said another way is: the front axle must never weigh less than 354 kg, and the rear axle must never weigh less than 429 kg. Additional weight per axle is unregulated.

Good point. It would hurt to carry extra weight though......

[Tommy Cookers]

The COG and weight distribution are not the same thing, the COG is a calculated point that will balance the car. The weight distribution is calculated by corner weights.

The location of the c.g. (actually center of mass) determines the weight distribution on the front/rear.....

guessing rather than checking I'd say......

CG and 'weight distribution' are 'the same thing' - for factors that vary linearly with position of the constituent masses

CG and 'weight distribution' aren't the same thing - for factors that vary with the square of their positions eg 'PMI'

corner weights won't tell us what the 'PMI' is (or what the other 'MI's are)

[Big Tea]

Sky Germany just reported that the "fluid" Verstappen mentioned was FUEL. They did not say where this information comes from, but they are well informed usually. So Verstappens car seemed to have a fuel-leak. The problem probably was the fuel line that connects the fuel tank with the high pressure pump on top of the engine, which takes the fuel pressure for the direct injection system.
The word is that E10 damages this fuel line.

It did not seem 'vigorous' enough to be fuel burning. Then again, it may have been a small amount that set fire to something else then stopped with the engine

[godlameroso]

Also, weight distribution is measured on corner weights, not a knife edge. Each tire is weighed, then the weights are tallied up. Front axle has to weigh ~5% less than the rear, that's all, COG can be changed because as far as the corner scales are concerned, the COG is the tire contact patch.

The "corner weight" is a direct function of the X-distance between the CoG and the resultant force (pressure*area) at the tire contact patch. "Axles" don't matter. As soon as the CoG moves in the x-dimension, the weight distribution measured at the contact patch changes.

Does it? How come short people can weigh just as much as tall people?

Again, cars are 3d, what you say works only in 1 dimension, it breaks down the second you add an extra degree of freedom.

In order to determine the COG using math you have to do the following.

For a general shaped object, there is a simple mechanical way to determine the center of gravity:

If we just balance the object using a string or an edge, the point at which the object is balanced is the center of gravity. (Just like balancing a pencil on your finger!)
Another, more complicated way, is a two step method. In Step 1, you hang the object from any point and you drop a weighted string from the same point. Draw a line on the object along the string. For Step 2, repeat the procedure from another point on the object You now have two lines drawn on the object which intersect. The center of gravity is the point where the lines intersect. This procedure works well for irregularly shaped objects that are hard to balance.
If the mass of the object is not uniformly distributed, we must use calculus to determine center of gravity. We will use the symbol S dw to denote the integration of a continuous function with respect to weight. Then the center of gravity can be determined from:

cg * W = S x dw

where x is the distance from a reference line, dw is an increment of weight, and W is the total weight of the object. To evaluate the right side, we have to determine how the weight varies geometrically. From the weight equation, we know that:

w = m * g

where m is the mass of the object, and g is the gravitational constant. In turn, the mass m of any object is equal to the density, rho, of the object times the volume, V:

m = rho * V

We can combine the last two equations:

w = g * rho * V

then

dw = g * rho * dV

dw = g * rho(x,y,z) * dx dy dz

If we have a functional form for the mass distribution, we can solve the equation for the center of gravity:

cg * W = g * SSS x * rho(x,y,z) dx dy dz

where SSS indicates a triple integral over dx. dy. and dz. If we don't know the functional form of the mass distribution, we can numerically integrate the equation using a spreadsheet. Divide the distance into a number of small volume segments and determining the average value of the weight/volume (density times gravity) over that small segment. Taking the sum of the average value of the weight/volume times the distance times the volume segment divided by the weight will produce the center of gravity.