Mercedes W13

[Big Tea]

It's ironic how some of our members slate Reddit members and other forums of the same ilk and question their IQ...

Is it to late to change my mind and pick the red pill?

No. You only get one chance to pick the red pill I heard. The fact that you met Morpheus of all people and turned him down means you are stuck here forever.

What is the difference between a matrix and a grid?

[PlatinumZealot]

It's ironic how some of our members slate Reddit members and other forums of the same ilk and question their IQ...

Is it to late to change my mind and pick the red pill?

No. You only get one chance to pick the red pill I heard. The fact that you met Morpheus of all people and turned him down means you are stuck here forever.

What is the difference between a matrix and a grid?

I suppose a matrix can be operated on whereas a grid is just a passive construct.

[Martin Keene]

What else can it be?

I think it is a suspension issue, which is kind of reinforced by the above comment. Follow me through with this; as the car speeds up the downforce increases, the suspension compresses, the suspension gets compressed to the point the underfloor stalls, the downforce collapses and the car pop's back up, rinse and repeat. If the car had infinitely stiff suspension it wouldn't compress under the downforce and wouldn't porpoise. But why do I think that means is it suspension?

It is widely regarded that Mercedes were the leaders of trick hydraulic suspension, they were the first with FRIC, etc. I suspect the drastically simplified suspension has really hurt them and they have more downforce than they can actually control.

[Big Tea]

No. You only get one chance to pick the red pill I heard. The fact that you met Morpheus of all people and turned him down means you are stuck here forever.

What is the difference between a matrix and a grid?

I suppose a matrix can be operated on whereas a grid is just a passive construct.

Sorry, I mis-directed you there. I mean why no matrix in F1 starts. ( Dont bother to answer I know it was a stupid quip)

[tuj]

First off, apologies for not having read all 155 pages. I did some searches within the thread around the keel and didn't see anything about this, so I was curious what's going on here in this picture?

I've heard reports that RB and Ferrari (and more?) are using some kind of sprung keel / T-tray / splitter. This is obviously a critical area of the car. Previously when cars needed more ballast, the keel was the place to put it to get the right weight distribution and put it as low as possible. Since 2001(?) we've seen teams (notably Ferrari) running sprung T-trays. This was done such that rake could be increased without raising rear ride height. Normally the splitter would bottom out before the front wing would drop as much as designed. Stepney revealed specific numbers about the deflection of the splitter and the subsequent drop at the front wing (at 100mph, the deflection allowed 7-8mm lower T-tray which resulted in 19-20mm lower front wing).

From the same information revealed by the Spygate investigation, it appears (at least then) that the ideal F1 car produces max downforce at 125mph or below and then shed drag above that speed. This would generally explain all of the attempts we have seen at stalling the rear wing or stalling the diffuser. An item that was never (AFAIK) fully explained was the use of a "buckling stay" in this area, essentially a non-linear spring, a spring with a distinct inflection point. This would in theory be tuned to the speed at which the transition to drag-shed should occur. Talk about the Merc last year near the end of the season mentioned a stalling rear diffuser as part of their package.

Clearly this was a very important area of the car and based on what I have seen in design variations in 2022, it would seem to be even more critical. Lots of components have been relocated to this area on many teams, suggesting a return to using this area for 'ballast' (not that the cars need much/any ballast now).

What do you make of this hinged access panel in the keel on the Merc? From what I can tell, this panel would be in the vertical position when the car is ready. Certainly access to components in the keel is important, esp. if teams have relocated things like various electronics there. However this seems to be something more. There is a large arm on a hinge in the rear portion of the panel and another smaller hinge just forward of the center of the panel. I'm rather baffled at what's going on here; thoughts?

[Another thought after looking at the RBR keel with the spring setup, is this the actual keel and the large arm is some sort of lever/spring? I have trouble w/ that bc the RBR keel is much much thicker, missing something?]

(credit: Giorgio Piola and Sutton Images)

[matteosc]

I think it is a suspension issue, which is kind of reinforced by the above comment. Follow me through with this; as the car speeds up the downforce increases, the suspension compresses, the suspension gets compressed to the point the underfloor stalls, the downforce collapses and the car pop's back up, rinse and repeat. If the car had infinitely stiff suspension it wouldn't compress under the downforce and wouldn't porpoise. But why do I think that means is it suspension?

It is widely regarded that Mercedes were the leaders of trick hydraulic suspension, they were the first with FRIC, etc. I suspect the drastically simplified suspension has really hurt them and they have more downforce than they can actually control.

That is exactly where the porpoising is coming from, but as you see it is related to both aero and suspensions. There are limits to what you can do with suspensions and compromises need to be made to balance mechanical grip/curb riding and porpoising. Clearly Mercedes was not able to find a good compromise, or such compromise does not exists with the current car package.
They definitely lost a lot of "weapons" in the suspension department, but I think a big part of the problem is that they were not able to correctly simulate porpoising (as Russell reported here). Difficult to simulate solutions if you cannot simulate the problem.

[f1jcw]

What was the reason for removing Hydraulic suspension?

Is it too expensive or was it away of removing a merc strength

[tuj]

They definitely lost a lot of "weapons" in the suspension department

Agreed, the loss of inerter, all hydraulic members both big blows. It looks like everyone is still using some kind of heave arrangement now via mechanical means. My question is how much can you play with the shocks? I was under the impression that aside from needing to be passive, these items were largely unlimited. In many lower 'spec' racing series where the available changes are limited, trick shocks have often been employed. An example is a softly sprung street car with large amounts of low-speed rebound dialed in. The car will effectively 'jack down' and the ride height during the event will be lower than the static car.

Much can be done with rebound and compression curves inside the shock to cause digressive valving, e.g. an inflection point in the curve. I'm wondering if a displacement-based mechanism could be used within the shock? The idea here would be that the first 80% of travel is normal compression and the last 20% is massively increased. This "20%" point would be tuned to just below the displacement at which the porpoising beings, thus presenting a soft 'bottom' to the ride height. This would let the static ride height remain low, preserve the spring rates and damping that is desired for most of the lap, and also avoid the oscillation issues at higher speeds by controlling ride height limit in this regime.

Are non-linear springs illegal? Helper springs illegal? Either of those could work too but I suspect they are verboten. I'm not sure how much you can regulate what happens inside the shock without spec parts. Thoughts?

What was the reason for removing Hydraulic suspension?

AFAIK, it was to reduce costs but it's also generally thought that Mercedes had the best hydraulic suspension components since they had been working with the system since ~2012(?). So a bit of both. The rules in general aimed to close as many avenues of development as possible. Hydraulics offers a lot of opportunities for complex suspension systems. In RCE, these are (strangely) modeled as *electrical* circuits, I guess there is a lot of similarity between accumulators and capacitors / orifices and resistors. Anyway, it's kind of dumb because by now a ton of the theory for hydraulic suspension is in the public domain, including FRICS.

[Owen.C93]

so I was curious what's going on here in this picture?

If I had to guess they are using the buckle plate to pass the deflection test that can then collapse at higher loads.



In the above side on view the yellow would be nominal, red under the FIA load, and green during track impacts. It's exaggerated but one advantage could be that the deflection curve gives a very small window of high force resistance which could help with plank wear.

Can't see why this would be preferred over a spring damper, other than weight. A damper system might even be useful for porpoising management.

[tuj]

A damper system might even be useful for porpoising management.

In 2007 Stepney suggested that Ferrari's T-tray, being hinged, controlled, and of variable mass, was actually a tuned mass damper. This was actually part of his defense, in that if such devices were legal, all teams would need to develop them and that the mass damper concept had already been banned.

Did Ferrari go back to the old trick? Is their keel arrangement with the damper doing more than we think?

[tuj]

In the above side on view the yellow would be nominal, red under the FIA load, and green during track impacts. It's exaggerated but one advantage could be that the deflection curve gives a very small window of high force resistance which could help with plank wear.

Interesting. How would you explain the transition of the vertical surface from convex to concave as it looks in your diagram? Not saying it's not so, just not exactly sure what would do that. From the lower hinge point I don't see what force would sort of 'pop' the stay the other direction. Maybe just a threshold of bending in the carbon? I had not thought about the top of the arm being fixed to a point. For some reason I was thinking it was a hinged lever.

[Stu]

What else can it be?

I think it is a suspension issue, which is kind of reinforced by the above comment. Follow me through with this; as the car speeds up the downforce increases, the suspension compresses, the suspension gets compressed to the point the underfloor stalls, the downforce collapses and the car pop's back up, rinse and repeat. If the car had infinitely stiff suspension it wouldn't compress under the downforce and wouldn't porpoise. But why do I think that means is it suspension?

It is widely regarded that Mercedes were the leaders of trick hydraulic suspension, they were the first with FRIC, etc. I suspect the drastically simplified suspension has really hurt them and they have more downforce than they can actually control.

Renault/Alpine/Lotus/Enstone we’re the first with FRIC, AFAIK. If it was as simple as ‘over-compression’ of the suspension, stiffer springs would cure the problem; it is bigger than that.

[matteosc]

They definitely lost a lot of "weapons" in the suspension department

Agreed, the loss of inerter, all hydraulic members both big blows. It looks like everyone is still using some kind of heave arrangement now via mechanical means. My question is how much can you play with the shocks? I was under the impression that aside from needing to be passive, these items were largely unlimited. In many lower 'spec' racing series where the available changes are limited, trick shocks have often been employed. An example is a softly sprung street car with large amounts of low-speed rebound dialed in. The car will effectively 'jack down' and the ride height during the event will be lower than the static car.

Much can be done with rebound and compression curves inside the shock to cause digressive valving, e.g. an inflection point in the curve. I'm wondering if a displacement-based mechanism could be used within the shock? The idea here would be that the first 80% of travel is normal compression and the last 20% is massively increased. This "20%" point would be tuned to just below the displacement at which the porpoising beings, thus presenting a soft 'bottom' to the ride height. This would let the static ride height remain low, preserve the spring rates and damping that is desired for most of the lap, and also avoid the oscillation issues at higher speeds by controlling ride height limit in this regime.

Are non-linear springs illegal? Helper springs illegal? Either of those could work too but I suspect they are verboten. I'm not sure how much you can regulate what happens inside the shock without spec parts. Thoughts?

Non-linear springs are not illegal, but while it is very easy to have stiffer behavior for large/fast deformation (stiffening) it is very difficult to do the opposite. Unfortunately porpoising is a relatively "slow" phenomenon, while riding a curb is "fast"; you can think at them as low and high frequency events respectively (not exactly what it is, but to give you an idea...). In this case you would need a suspension which is stiff a low frequencies and soft at high frequencies, which is extremely difficult (if not impossible) to do.

[AR3-GP]

so I was curious what's going on here in this picture?

If I had to guess they are using the buckle plate to pass the deflection test that can then collapse at higher loads.

https://i.imgur.com/JBDbUmq.png

In the above side on view the yellow would be nominal, red under the FIA load, and green during track impacts. It's exaggerated but one advantage could be that the deflection curve gives a very small window of high force resistance which could help with plank wear.

Can't see why this would be preferred over a spring damper, other than weight. A damper system might even be useful for porpoising management.

More or less yes. It appears to have the advantage of being potentially lighter in weight. Every single F1 team is going to have a spring medium between the leading edge of the t-tray and the chassis to absorb kerb bumps without cracking the floor and to fine tune the ability to pass the FIA deflection test.

[mantikos]

What else can it be?

I think it is a suspension issue, which is kind of reinforced by the above comment. Follow me through with this; as the car speeds up the downforce increases, the suspension compresses, the suspension gets compressed to the point the underfloor stalls, the downforce collapses and the car pop's back up, rinse and repeat. If the car had infinitely stiff suspension it wouldn't compress under the downforce and wouldn't porpoise. But why do I think that means is it suspension?

It is widely regarded that Mercedes were the leaders of trick hydraulic suspension, they were the first with FRIC, etc. I suspect the drastically simplified suspension has really hurt them and they have more downforce than they can actually control.

Same thing was posted on the prior page.