F1 2010: Ride height adjustments during pit stops

[autogyro]

I would go along with that Dave.
There is no evidence to prove a complex ride levelling system on the RB and it should be possible to gain the leed they have using conventional suspension.
The self levelling systems here described work well in theory but to apply them on an F1 car would be very difficult.
Might be worth a try though.

[hollus]

A slightly, very slightly off-topic comment here:
Don't the cars corner at a higher speed when they have less fuel, since there is less mass to accelerate laterally?
Then a lighter car would have more downforce where it matters most, in the middle of the corner, and then we are no longer speaking of a 160Kg difference in the apparent weight of the car (meaning load on the suspension). This would apply at the braking areas too, as the car would reach them at a higher speed and stop braking at a higher speed.
And now the stupid comment, maybe RedBull simply has so much downforce that the two effects (fuel weight and downforce difference) cancel each other out and the car just behaves as if it always has the same fuel load?

[RacingManiac]

That's normal force on tire, but you are not counting inertia...more mass(fuel) would constitute more mass being accelerated(in lateral or longitudinal direction), making it harder to change direction(cornering and braking).

[hollus]

Maybe I didn't explain myself properly. You are right, the extra inertia is why the cars are slower with more fuel. With less fuel, less inertia means higher cornering speed and more downforce in the corner. Thus, with less fuel, you have more downforce, and with more fuel you have less downforce. Then the total of weight + downforce stays approximately constant and the ride height (in the corner and braking areas, where it counts) stays about constant too.
Or that's my idea at least. I might be completely wrong. How much does the cornering speed change with 100Kg less fuel in the car?

[pgj]

This is going slightly off topic, but how is an active suspension defined. What system/process would cause the scrutineers to say that is an active suspension?

[edit grammar]

[forty-two]

How sensitive is the Novamat damper to static loads? and how does it differentiate between aerodynamic load and vehicle weight. Considering it was made for vehicles like SUVs which have no such thing as aerodynamic loading.

Can someone explain in simple logical terms how this thing responds?
I find it interesting that on low fuel the car is leveled down, then goes to parc ferm untroubled, then fueled for the race and it magically pushes back and increase the shock length to compensate for the weight, without any interference from the mechanics.

I personally wonder if the system in question somehow utilises the heat from the engine to crank the car down slowly throughout the race distance, perhaps this would explain (or be at least another reason for) the repackaged exhaust layout on the RB car.

I suspect that an F1 engine will be "up to operating temp" within a lap or three, but what if somehow the RB6 exhaust layout had a thermal tap which would gradually heat up throughout race distance, lowering the car as it gets warmer. All the team would then have to do to achieve the apparent inconsistent ride heights (from start of qualifying - to end of qualifying - to start of race - to end of race) would be to artificially pre-heat this device before qualifying begins, thus cranking the car down to it's low fuel height. As the car then cools after qualifying, the actuator would return to it's pre-race (high fuel load) height ready for fuelling before the start of the race.

I have no evidence to back up this claim, but it strikes me that such a system would be legal (being passive), if not for a grey area around the "warm the device before qualifying". Perhaps a way around this would be to insulate the "device" at the end of FP3 in order to keep it hot before the start of Q1?

I initially started wondering this when it looked like a bit of the bodywork had broken around the pullrod at the end of the Bahrain race, perhaps this happened because the engine was a lot hotter than anticipated?? Perhaps this is why Vettel had to cruise the last few laps because the device in question had gotten too hot, lowering the car by too much to risk full chat laps for fear of grounding the plank.

What do you think Ringo?

[forty-two]

This is going slightly off topic, but how is an active suspension defined. What system/process would cause the scrutineers to say that is an active suspension?

[edit grammar]

I don't think your question is off topic at all, far from it in fact. Although I fear that my own rambling below could well be considered off topic (sorry guys!).

My understanding of Active vs. Passive is largely informed by the dictionary definition of the word active:

Active - Having the power or quality of acting; causing change; communicating action or motion; acting; — opposed to passive,

One example of the difference I encounter regularly is when discussing movement detection devices.

One type of device is called a "Passive Infra Red Movement Detector" which works by detecting a difference in the pattern of Infra Red light which lands on it's two (at least) sensors.

Another type of device is called an "Active Infra-Red Beam Interruption Detector". This type of device works by shining an Infra-Red light source at a target sensor. If the light beam is interrupted, the sensor can no-longer "see" the IR light, and an alarm is raised.

In terms of motor racing, I would contend therefore that if a system relied upon say a stepper motor (which requires an external energy input) to crank the ride height up or down, that would constitute an Active system. A system which say was driven by the heat given off by the exhaust as the race progresses (which relies purely on heat which would be there anyway, so no direct external energy input is required) could be described as passive.

Although as per usual, I am happy to be put right by some of the boffins on this forum.

[DaveW]

This is going slightly off topic, but how is an active suspension defined. What system/process would cause the scrutineers to say that is an active suspension?

Strictly, a "passive" suspension will both store energy (springs & inerters) and dissipate energy (dampers). An "active" suspension can, in addition, add energy (either potential or kinetic) to the suspension.

The FIA has a more draconian definition, as specified in regulations 10.1.2 and 10.2.2. (see Richard Leeds' post, above). Regulation 10.2.2 specifically precludes any form of "intelligent" suspension control (e.g. adaptive dampers).

Renault's "mass damper" (or dynamic absorber) was legal by both definitions, but it was still declared illegal (curiously, the device was banned shortly after a representative of a Certain Team declared that the mass damper worked only with Michelin tyres).

In my view, a "Nivomat" style damper would also be legal by both definitions. It is anybody's guess what the view of the FIA might be.

[ringo]

... However, keeping the range of dynamic suspension position tight at each corner requires spring and shock rates that are not optimum for mechanical grip. Compromises have to be made. You mentioned digressive rebound and chassis compliance. These are ways of improving mechanical grip within the context of tight ride height control.

Am I understanding this correctly?

Back to the topic under discussion. I think your "Nivomat" solution to compensate for varying fuel weight would introduce a couple of problems. Its weight would, in most cases, increase the vertical height of the centre of gravity, and it would be difficult to control its tendency to "hunt" by changing pressure whenever the mean load supported by the suspension changed. My comment about the ratio of fuel load compared with aero load is relevant here, I think, because you would be requiring the system to operate accurately with a signal/noise ratio of around 0.1. I could imagine it actually increasing the mean ride height through corners following long straights, for example. I can't think that would be an easy problem to solve.

You wording is much better than mine. This was also my speculation about the system. Another concern is the response time to inputs and if the system overshoots. With the speed that load conditions change in F1, it is hard to see this thing not behaving erratically.

[ringo]

I have 2 mechanical concepts that might work. I am just checking out the feasibility.
One is based on varying the plane of load application based on the push-rod force and the other is a ratcheted system.
Only problem with the ratcheted system is restoring the system for the race start on heavy fuel.

One other consideration to make is that when the fuel load reduces, the height increase is not the same front to back if the tank is not biased front to back. It is possible the car can be set up to increase rake angle as the load burns of.

[pgj]

Thank you both for the relpies.

It was the Nivomat damper that got me thinking. If the top chamber each damper was connected to the bottom chamber of the other damper, would this be an active suspension?

It is a question that I have been asking myself for a long time now. When Williams developed its AS it had no end of trouble in getting it to work properly. Williams has never disclosed how the final version worked. However, I remember an interview with Patrick Head when he said that they had had immense problems in getting to hydraulics working properly. They had problems with software and actuators. In another interview he said that the final AS was surprisingly crude. I have always wondered if it was something as simple as the model suggested with front and rear pairs connected through a reservoir. I know that the Williams version was hydraulic, but in principle a gas powered system could also work.

If there is no additional energy entering the system other than through dissipating energy from damper compression, would that be active or passive?

[RacingManiac]

If you are just allowing the fluid to be cross linked and controlled through some valving, I don't think that would be considered active. I think something like the Kinetic Suspension System is already like that. But if you are adding energy into the system by pumping fluid from one side to another you would be doing active work.

[autogyro]

If you are just allowing the fluid to be cross linked and controlled through some valving, I don't think that would be considered active. I think something like the Kinetic Suspension System is already like that. But if you are adding energy into the system by pumping fluid from one side to another you would be doing active work.

Surely passive suspension is a self contained suspension system that simply controls input from forces generated by vehicle movement.
Active suspension is inputing power from another source other than this?

[RacingManiac]

Basically thats how I understand it anyway. Though if you are scavenging energy off somewhere else but input it into suspension, I think that might be active as well.

At the end of the day though, governing bodies can deny whatever they want...Kinetic Suspension System is banned from WRC/Rally Raid, even though its a passive system. Though thats after Citroen and Mitsubishi's domination in those field...

[ringo]

How about this, legal?

So proud of it i put my name on it, though it's simplistic in how the shock itself operates.



No external power and directly linked to fuel weight, very simple and needs no adjustment by mechanics. The internals of the shock were simplified by me; i am not very knowledgeable on F1 shock technology so ignore that.

Tank and valve are lightly spring loaded. Realistically the needle valve should be implemented in a way that the shock force is not acting back on the tank piston. Maybe if it was threaded and moved via hydraulic motor motion and supported by torsional spring. This way only torque can move it and not pressure force.

edit: feel free to criticize and correct. It's only an initial thought, it's possibly not visually accurate in terms of holding a specific ride height, but the restriction could limit shock motion. Any F1 team should be able to make the proper corrections too.