Mercedes W12

[zibby43]

There's a significant difference in the speed of the cars.

Agreed. To me, the W12 looks pretty similar to its predecessors on the rake front.

[Tizz]

I'm not so sure. You see the car a quite a different angle. It might be something visual ?

[jumpingfish]

Does the amount of fuel affect the rake?

[NathanOlder]

Does the amount of fuel affect the rake?

It shouldn't do as the fuel cell will be as central as possible so it doesn't change the balance as the fuel load goes down.

[jumpingfish]

Does the amount of fuel affect the rake?

It shouldn't do as the fuel cell will be as central as possible so it doesn't change the balance as the fuel load goes down.

Thank you, good to know. Thought it can affect at the start of the race when cars are full loaded.

[Owen.C93]

Does the amount of fuel affect the rake?

It shouldn't do as the fuel cell will be as central as possible so it doesn't change the balance as the fuel load goes down.

There's a lot less heave stiffness in the rear so it will bring it down a bit more at the low speed.

[aleks_ader]

Does fuel cell affect rake - aero platform? Sure it does a bit.

Especially under braking - pitch. Team even use that to take advantage.

Roll and steering response is another issue witch effect tire patches. Hence different tire heating, wear patterns and ultimately grip. Aero balance changes could be affected if teams are not careful. Ofc problem could be alleviate with "nice" "balanced" aero design.

Hence all that media mantra about balance and snappy cars or nervous drivers. But again because problem exist for centuries of racing. So teams honed its skills and studied its effect quite nicely i would say.

So yeah predictable and low CofG still gives you less headaches for sure. Contradictory nowadays teams consciously raising CofG for bigger gain elsewhere. Normally in names of aero benefits - high noses, high wing blow exhausts, high FW/RW wishbones, central rads, raised gearboxes, raised diffs casings, split turbo design, raised h2o intercooler, high tuck-in plumbing all over car, raised crash structures etc.

[PlatinumZealot]

That is a good question. I am not an expert, and don't have an answer myself, but I will try to deduce.

The objective of the suspension engineers is to keep the aero-platform as stable as possible, or at least the behavior is to be as predictable as possible. Rake will obviously change during braking because of the pitching moments involved, but will the rake change, all else being the same, at a lower fuel level? I can't see what forces or moments involved would change that and why would you want to change it if the objective is to keep a stable and predictable (especially by the driver) aero platform? I would say, even though the ride height changes, the rake does not noticeably change with fuel load.

[marcush]

reference influence of vertical load on aero behaviour.

This is the actual magic .
every change in load has a direct consequence on rideheight as by rules all aero must be generated on the fully sprung part of the car ....well in rheory at least..

So , as the car is considerably stiffer vertically at the front , ride hwight changes through fuelloads must have a
rear biased effect on rideheight ..and actually lower rear has the effect of rising the front wing as the car is pivoting around the stiffer front axle...

One has to take into account also tyre vertical stiffness which is also a spring ,influenced by tyre pressure and tyre construction .This acts in series with the
suspension springs !

But there is more to it:
tyre load sensivity .
Tyres gain grip with rising vertical load -instantly !
So fluctuating aero , wandering center of pressure all have severe and instant influence on available mechanical grip .
This is what its all about and why you cannot tolerate fluctuating aeroloads , it is like shifting corner weights at lightning speed but not necessarily as,a result of driver input ...so the driver is just a passenger...

[aral]

Back to the actual car please, guys

[marcush]

it's the w12s core problem, As at lower rear ride heights (less rake) , dynamic ride height changes at the rear have a bigger influence on downforce generated .
Thats quite logic , as the volume below the car is changing more in terms of percentage , not in terms of delta for
the same vertical movement.

[Xwang]

I do not know if it only a shade, but looking at the left part of the diffuser it seems like the divergent part does not join to the floor of the car (it seems to much dark and too much contrast). Does it seem strange to you too?

[dren]

it's the w12s core problem, As at lower rear ride heights (less rake) , dynamic ride height changes at the rear have a bigger influence on downforce generated .
Thats quite logic , as the volume below the car is changing more in terms of percentage , not in terms of delta for
the same vertical movement.

Makes sense, but you would have thought Mercedes past cars would have suffered similar problems.

[BerrageizF1]

[atanatizante]

I`ve read on another forum that it wasn`t 2021 aero regs the hardest thing that hit them. Instead, it was the tyres that now faces 2 big problems:

1.Firstly and the most important fact is that the 2021 tyre has a harder rubber chemical composition (that`s the reason they lose now almost 1s/lap, tyre spec dependent). This was done in order to cope with increasing lateral loads plus even higher DF levels than 2020 which is supposed to appear mid-season. In addition, Pirelli and F1 teams have the same desire just to lower the tyre pressure in the race, obviously for different reasons.

2.Secondly, the 2021 rear tyre has a new construction shape and flex more, which is both harder to simulate (with CFD models & wind tunnel) and to control the wake with the allowed floor strakes/vortex generators. This tyre wake induce an inconsistency in diffuser DF levels, something that Merc was always prone to get with their lower rake philosophy, instead of peak DF like Red Bull is hunting with high rake …

What does mean harder tyres? One could say lower grip but that is not the whole picture. Hard tyres mean also a higher operation window! I don`t have a 2021 tyre operation window (and maybe someone could help me with this) but with lower levels of DF for this season, it must require some changes to the rear suspension, something that successfully Red Bull did. It said that Merc regrets they didn`t simulate 2021 DF levels back in Portimao and Abu Dhabi last year when they had the opportunity to test 2021 tyres. They went to not disclose any aero developments in order to give no ideas to their rivals and now bits them big time …

What`s the proof? Just look at the race when the W12 car was on full tanks and medium tyres! It was on pair (if not faster) with RB16B, something that Horner admitted frankly after the race. And another proof is their poor qualy results. One could say that they were setting the car towards the race, hence for the medium and hard tyre. This led to overheating the soft tyres in qualy, down to too much DF levels required for medium and hard tyres to work in their optimum operation window. But the the real reason is that their 2021 rear aero in conjunction with their last year rear suspension doesn`t correlate in real life with their simulations/CFD models! This doesn`t cope well with this 2021 (harder) tyres, which led to overheating the soft tyres in qualy, especially in the third sector and was something that we witness in the test before the race (anyone rings the bells with Lewis` spin in turn 14 on C4 soft tyre?).

Maybe I`m wrong with the rear suspension and they`ll bring a new front wing in order to cure the rear instability/lack of DF which brings new and much powerful vortex generators in order to seal the diffuser better, just to be in line with what James Alison said regarding where their tokens were spent. Unfortunately, this will require some time (track engineer Shovlin suggested that Imola and Portimao will have the same car) both to design, manufacture and crush tested … hope it rains, why not, in order to give them a breather …