41 replies to this topic

[Don Rapido]

I was reading the statement of Max Mosley regarding policing maximum downforce on cars in the future. FIA's idea is that at the inspection the plank of the car must touch the bridge on which the car is put after they put the weights on it.

However as I see it, it may be a problem if some team has very stiff suspension setting and the plank does not touch the bridge. They may argue that the downforce is lower than the limit but the setup is just so stiff that the plank of the car does not come low enough.

I may not have completely understood what Max meant because he did not elaborate much on this issue but it is a moot point to me.

I'd like to hear what you folks think about it.

[LMP900]

It's a clever way of limiting downforce. Whatever your wheel rate, the car must ground out at the specified aero load. Except that damping could probably be used to prop the car up.

[OO7]

Couldn't the width of the plank be reduced further from 300mm ( I'm not sure if this is an accurate current figure) to 100mm?.

obi

[Tooheavy]

Originally posted by LMP900
It's a clever way of limiting downforce. Whatever your wheel rate, the car must ground out at the specified aero load. Except that damping could probably be used to prop the car up.

I think this is a great idea, simple to test for and it can free up aero and wing design a lot allowing more efficient downforce with less drag. You would probably need to test with a standard tyre pressure, hopefully representative of race tyre pressures, may be less of an issue with low profile tyres.

Regarding dodgy shocks - maybe require a spec shock, or require that shocks be inspected and/or tested to ensure that their performance in scrutineering is not significantly different to their race performance, don't want shocks that miraculously become springs during the race when the oil heats up or whatever. Shouldn't be too hard on a shock dyno.

[Ross Stonefeld]

Lets say the FIA limit is 5000lbs of download (however they specify and measure that). Lets say your car makes 10,000lbs. Wouldnt your spring system, which supports 10k, be more than capable of handling 5?

[Slumberer]

Perhaps someone could explain this better to me, but this seems to me to be measuring the stiffness of the suspension, not the aero load.
(And couldn't that be varied quite a lot by varying tyre pressures during the race?)

Also would there be any safety concerns about cars bottoming out the suspension?

It's when you hear vague sounding regulations like this that you wish Colin Chapman was still here to test the interpretation....

[zac510]

When I first heard Max was thinking of limiting downforce I conjurred up an image of a wind tunnel in the back of an 18-wheeler being toured around to all the events for the race scrutineering Then I realised that was hopelessly impractical!

I look forward to seeing how they implement this.

[Ben]

Originally posted by Ross Stonefeld
Lets say the FIA limit is 5000lbs of download (however they specify and measure that). Lets say your car makes 10,000lbs. Wouldnt your spring system, which supports 10k, be more than capable of handling 5?

You've got it the wrong way round. If it can't support 5000 (it bottoms out as per the test) then it won't support more than that ergo the maximum level of downforce is restricted.

Ben

[Ross Stonefeld]

Ah, I misread what they were doing I was going to say, seemed like a stupid rule the way I was understanding it.

[Zoe]

Didn't Mercedes come up with a way to "work around" the rules in DTM by freezing the shock absorbers just before the test?
I think I have a report (in German) somewhere about that one.

Zoe

[Ross Stonefeld]

Post-qual check in F1 would be pretty easy no?

[Zoe]

It would probably be, yes. However, tire tread width wasn't measured after the race as well for a long time, leading to some controversy.

Zoe

[StephenJK]

I’m not a racer, but I know people who are. I’ve always been impressed with the innovations that the boys can come up with in some very basic racing series to enhance the performance of a race car. Whether something as basic as a really long fuel line to increase “tank” capacity, or with a 3/4 sprint car (hollow tube) frame partially filled with liquid mercury and fitted with a manual valve to transfer weight to the inside.

With regards to F1, and regardless of the suspension type, if the plank has to fully bottom to pass the applied weight test, part of the issue would seem to be how and where the weights are placed. If the only limitation on the car design is the package dimensions, standardized hard points for weight placement would be impractical.

Max has stated that: “And if the plank is touching the bridge at all points, the car is legal and if it's not then it's not. Now that obviously depends on having a single tyre manufacturer which is already in the regulations we circulated and would be done after the cars go into Parc Fermé following the qualifying and so on. But nobody that we've talked to has yet come up with a way of getting round it. Doesn't mean they can't but we're saying to them if you think of something clever tell us before it becomes concrete in the rules but we're pretty sure there isn't a way round it.”

I’m certainly not suggesting that the FIA or Max are perhaps a bit naïve, but if anyone in the F1 racing community can intuitively come up with a number of means of circumventing the downforce limitation, I hardly think they would be inclined to speak up.

So, how feasible is this proposed regulatory change for 2008, and is it remotely possible that it can be properly scrutinized?

[Ben]

Originally posted by StephenJK
standardized hard points for weight placement would be impractical.

I disagree. Why is it any different from having a mandatory lifting point in the roll hoop?

I've now read Tony Dodgins article and am starting to actually like the idea. Specifically that if you had this limit then all the stupid bodywork areas can be removed from the rules. The technical challenge of maximising L:D and stalling the flow on the straights, etc would keep the teams busy.

So assuming I now think the idea of a deflection test is a good one how would it be best to implement it?

Well three points are needed to define a plane. I would make the teams design in three loading points within a certain area, say one on the nose of the monocoque and two either side of the gearbox.

Rather than making the whole plank touch, again specify three points this time on the floor that you could maybe screw in small conical gauges. This would get around any plank wear arguments because you would then have a solid link to the reference plane.

I hate myself but Max may have a point on this one.

Ben

[StephenJK]

Ben,

That's the question, isn't it? Is it possible to have a simple static test that will unequivocally determine that the Parc Ferme scrutineering will satisfy even the most suspicious minds.

[angst]

I like this idea. It clears the way for the engineers to head in different directions, rather than having more and more bodywork restrictions and thus more and more homogeneous cars. I don't understand why it would require a single tyre manufacturer though. Surely the cars could be fitted with 'dummy' wheels for measurement, with basically solid rubber 'tyres'? As for the suspension components being designed to act differently at speed and while static, surely that would amount to active suspension and would be illegal?

[zac510]

Originally posted by angst Surely the cars could be fitted with 'dummy' wheels for measurement, with basically solid rubber 'tyres'? [/B]

Perhaps if the hubs were to sit on a fram with a standardised ride height then the weights applied?
They could apply the weight tests directly to the front and rear wings as they should be capable of withstanding the load anyway.

[alexbiker]

If they don't use dummy solid tyres, here's a way round: Blow up the tires hard for the race. Use dump valves which let a pre-set amount of air out when you tell them too. Blow the air out on the slowing down lap.

Alternatively, replace the springs with elastomers that stiffen when they get hot. Bingo, way stiffer suspension in the race. Make sure they heat up and cool down fast, and use the engine to heat them somehow. You could probably arrange something like that using remote reservoirs on the dampers, but trick the valving so that the remote unit is actually a hydropneumatic spring which is heat sensitive.

Yup, cheating is fun.

Alex

Edit: Another one - a little backwards play in the suspension which dramatically increases the springing rate when the car is moving - as in, car moves, suspension moves back into a stable position, the geometry of which raises the stiffness dramatically.

[Engineguy]

They could just get all the teams to promise not to do anything to subvert the intent of the rule.

Hey; stop laughing. Why you laughing?

[Bart]

I don't understand this, which is quite embarassing as I'm a physicist. But suppose you're running at a bumpy circuit (e.g., Interlagos). You need a fairly high ride height to avoid repeatedly bottoming out, so even at maximum downforce you wouldn't expect the car to touch the ground, right? So why should it do so on the test bridge?

[Ben]

Originally posted by Bart
I don't understand this, which is quite embarassing as I'm a physicist. But suppose you're running at a bumpy circuit (e.g., Interlagos). You need a fairly high ride height to avoid repeatedly bottoming out, so even at maximum downforce you wouldn't expect the car to touch the ground, right? So why should it do so on the test bridge?

I think it's wrong to keep thinking about the downforce level. When the car's at speed the wheels generate lift so a static test isn't going to be accurate in the sense of restricting the teams to X newtons of downforce.

I don't quite see the problem with bumpy tracks. F=Kx if F is the same (the load applied) and K goes down (softer springs) then x will go up hence the raised ride height and you still pass the test.

Ben

[zac510]

Originally posted by alexbiker

Alternatively, replace the springs with elastomers that stiffen when they get hot. Bingo, way stiffer suspension in the race. Make sure they heat up and cool down fast, and use the engine to heat them somehow. You could probably arrange something like that using remote reservoirs on the dampers, but trick the valving so that the remote unit is actually a hydropneumatic spring which is heat sensitive.

That's great, but you would want softer suspension in the race!

[RDV]

Engineguy-They could just get all the teams to promise not to do anything to subvert the intent of the rule.

Hey; stop laughing. Why you laughing?

[McGuire]

Right, let's have commitees of the competitors and suppliers draw up their own rules, then have them police themselves by "gentlemens' agreement." It worked so well in CART.

[wegmann]

I'm obviously too lazy to search, but didn't someone on this very forum suggest a very similar idea months ago? I just refuse to give Max and his cronies too much credit ...

[angst]

Originally posted by wegmann
I'm obviously too lazy to search, but didn't someone on this very forum suggest a very similar idea months ago? I just refuse to give Max and his cronies too much credit ...

I can't remember who it was, but the suggestion was definitely made on an AA forum. The thing that confuses the issue a little is that Max seemed to tie this idea in with the work that the FIA are doing with AMD. I don't really see how there is a link. The work with AMD is to attempt to find the best 'profiles' to promote close racing, an idea that must surely involve bodywork restrictions?

[ch2]

This method of policing a downforce rule is very interesting - rather than a downforce limit it is a suspension stiffness limit. There is another rule that goes along with it - the high grip floor plank. The idea is that if the car bottoms out the high grip floor will slow it down. So by saying that the floor must touch with a certain load on the car it would be impossible to use a higher level of downforce than that load and still have a fast car. There will be a at which the car would be bottoming out at high speed over bumps that would mean that the actual downforce could only be a percentage of the load limit.

Can you imagine a car going through Eau Rouge, flat out, the "high grip plank" hits the tarmac. The back end gets light due to the deceleration. What happens next?

[angst]

Originally posted by ch2
This method of policing a downforce rule is very interesting - rather than a downforce limit it is a suspension stiffness limit. There is another rule that goes along with it - the high grip floor plank. The idea is that if the car bottoms out the high grip floor will slow it down. So by saying that the floor must touch with a certain load on the car it would be impossible to use a higher level of downforce than that load and still have a fast car. There will be a at which the car would be bottoming out at high speed over bumps that would mean that the actual downforce could only be a percentage of the load limit.

Can you imagine a car going through Eau Rouge, flat out, the "high grip plank" hits the tarmac. The back end gets light due to the deceleration. What happens next?

Firstly, with geatly reduced downforce I think Eau Rouge being 'flat out' will be a thing of the past - it would become a real test of set-up and driver skill/balls. Secondly IF a car bottomed out there then the team involved will have f***ed up big time - I can't see them being that stupid.

[matthew jackson]

Wouldn,t we see a return of ground effect cars?

[Dmitriy_Guller]

That sounds like a stupidly dangerous idea to me. We know that all teams would try to get as much downforce as they can, and therefore every car would be at the point of just bottoming out at top speed. You can have situations where at high speed corners, where both aero load and weight transfer load is high, the cars would be riding on their bellies, which is what you absolutely do not want to have. Any rule that forces teams to trade safety for speed is a very dangerous one.

[Engineguy]

Originally posted by Dmitriy_Guller
That sounds like a stupidly dangerous idea to me. We know that all teams would try to get as much downforce as they can, and therefore every car would be at the point of just bottoming out at top speed. You can have situations where at high speed corners, where both aero load and weight transfer load is high, the cars would be riding on their bellies, which is what you absolutely do not want to have. Any rule that forces teams to trade safety for speed is a very dangerous one.

Dmitriy,
This is not something new... every team in F1, IRL, ChampCar, etc. have been playing this game for years. They always want to run the car as low as they can get by with, for both CG and ground effects reasons. If you run a few millimeters higher than your competitors you're giving up something to them. That's why they have the sacrificial planks... they know they'll kiss the pavement occasionally under certain combinations of conditions, and they do. It does amaze me that we see puffs of plank dust frequently, yet it seldom unloads the tires enough to cause a corresponding spin.

[Dmitriy_Guller]

Originally posted by Engineguy
Dmitriy,
This is not something new... every team in F1, IRL, ChampCar, etc. have been playing this game for years. They always want to run the car as low as they can get by with, for both CG and ground effects reasons. If you run a few millimeters higher than your competitors you're giving up something to them. That's why they have the sacrificial planks... they know they'll kiss the pavement occasionally under certain combinations of conditions, and they do. It does amaze me that we see puffs of plank dust frequently, yet it seldom unloads the tires enough to cause a corresponding spin.

I knew that, but I figured the stakes would be much higher with the new rules. With the new rules you cannot fix the problem of grounding in the corner by stiffening suspension (without making your car illegal), so you must reduce your downforce level to raise the car in the troublesome corner. That might give incentives to some ballsy drivers to cope with more grounding that they normally would in order to avoid giving away extra downforce in other parts of the circuit.

[McGuire]

Originally posted by Engineguy
This is not something new... every team in F1, IRL, ChampCar, etc. have been playing this game for years.

Yep. Also in NASCAR. Want to see something hilarious? This a FRONT spring now:

[kNt]

The Idea sounds quite nice, although they had to introduce restrictions on Suspensions, e.g. on the Materials used.
But I think it's a better restriction than all the boxes and front wing height and so on.

[Engineguy]

A place where you had better have your ride height just right... note the trail of plank dust ground into the pavement through Eau Rouge at today's Belgium GP:

[Dmitriy_Guller]

In any way, another unintended and related consequence I can think of is that teams would not be figuring out how to eek out all the downforce they'd be allowed to have without grounding, but rather how to dial in more than legally allowed and cope with the plank dragging on the track. It's the same kind of danger, with the rules causing a compromise that pure physics would never force.

[kos]

They cannot race trying to cope with dragging plank, because if more than 1 mm of the plank's thickness is worn out then the car will be declared illegal during post-race scrutineering.

[alexbiker]

Originally posted by zac510


That's great, but you would want softer suspension in the race!

No. No, no, no.

The idea of the static test is that the car has to be soft enough that excess downforce would bottom it out, taking load off the wheels and making the whole thing pointless.

If you stiffen the suspension as it runs on track, then you can use extra downforce and still pass the test.

Alex

[Dmitriy_Guller]

Originally posted by kos
They cannot race trying to cope with dragging plank, because if more than 1 mm of the plank's thickness is worn out then the car will be declared illegal during post-race scrutineering.

Sure, keeping the plank legal would be one of the challenges. However, as the brown racing line at Eau Rouge shows, there's room to play there.

[ch2]

The plank thickness rule quoted by kos is this years rule. Who knows what the 2008 rule will be? The main thing that has been said about the plank for 2008 is that it will be "high grip". A minimum wear rule would be superfluous - if the plank is indeed high grip and you want to let it sit on the track until 10mm has worn away you'll obviosly lose out.

Quotting Max "In combination with this, we will fit a high grip plank, that will stop people running the plank on the ground to get round the downforce regulation. That will also be a safety measure when drivers lose wheels with the new tarmac run-offs."

The cars bottoming out in Eau Rouge this weekend didn't appear to be having any problems - but what if the cars were decelerating as well?

What would the plank be made of? Rubber - it would have to be Michelin if they wanted high grip ;-p.

[alexbiker]

A plank made of Michelin rubber would probably have to be limited in high-speed corners.

Or a plank saving chicane installed at key points.

Alex

[zac510]

Originally posted by alexbiker


No. No, no, no.

The idea of the static test is that the car has to be soft enough that excess downforce would bottom it out, taking load off the wheels and making the whole thing pointless.

If you stiffen the suspension as it runs on track, then you can use extra downforce and still pass the test.

Ah sorry, took a while to get my head around that

Anyway, one word that Max has used that perhaps nobody has picked up on, is that the car will be tested on a bridge which may be 5, 10mm tall?
As far as I can see, the danger of bottoming out the car exists just as great today.