Ferrari SF21

A place to discuss the characteristics of the cars in Formula One, both current as well as historical. Laptimes, driver worshipping and team chatter does not belong here.
marcush
marcush
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Re: Ferrari SF21

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what is mechanical grip in an aerodominant environment ?
We should never forget , all downforce generated serves one (!)single purpose :
generating mechanical grip.
why does it generate generate grip ?
because the tyres grip level is vertical load sensisitive (more load =more grip)
The idea of generating the same amount of grip with less downforce is not a valid concept ,period.Reduce downforce and your grip potential diminishes .
Of course tyre grip is also temperature sensitive and you got surface temp as well as core (construction temps) , the generation of temps a function of how you work the tyres .
There is a line of thought in F1 more or less ignoring the mechanical side of wheel motion geometric control .
we saw impossible wishbone angles for aero reasons ,we still see brutally restrained vertical motion at the front for aero reasons .

Sevach
Sevach
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Re: Ferrari SF21

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AR3-GP
AR3-GP
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Re: Ferrari SF21

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marcush wrote:
Tue Jul 13, 2021 9:02 am
what is mechanical grip in an aerodominant environment ?
We should never forget , all downforce generated serves one (!)single purpose :
generating mechanical grip.
why does it generate generate grip ?
because the tyres grip level is vertical load sensisitive (more load =more grip)
The idea of generating the same amount of grip with less downforce is not a valid concept ,period.Reduce downforce and your grip potential diminishes .
Of course tyre grip is also temperature sensitive and you got surface temp as well as core (construction temps) , the generation of temps a function of how you work the tyres .
There is a line of thought in F1 more or less ignoring the mechanical side of wheel motion geometric control .
we saw impossible wishbone angles for aero reasons ,we still see brutally restrained vertical motion at the front for aero reasons .
I think you are jumbling up concepts. Mechanical and aerodynamic grip are two different things. They act together. One on top of the other. The importance of one vs the other changes as a function of speed.

Mechanical grip is a function of chassis stiffness, spring and damper rates, center of gravity, load transfer, and how well the chassis applies it's own weight consistently over the 4 contact patches. Aero is simply additive.

For example, you can have a car with a very high center of gravity. Load will transfer from front to rear and side to side much more aggressively meaning a wheel is unloaded excessively which lowers your braking and low speed cornering potential. Similarly, poor ride compliance through a corner on a bumpy circuit leads to a low normal force at the contact patch. Optimizing these chassis parameters increases mechanical grip. Optimizing aerodynamics increases aerodynamic grip.

I don't think semantics is of value here. Yes the aerodynamic loads must act through the tire, but aerodynamic loads in the absence of a change in the vehicle pitch,roll, yaw, are not affected by load transfer. Mechanical grip is. To some extent, aerodynamics are always turned on, but the importance of aero diminishes at very low speeds.
Last edited by AR3-GP on Tue Jul 13, 2021 7:15 pm, edited 8 times in total.

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godlameroso
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Location: Miami FL

Re: Ferrari SF21

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Could it be possible to say that mechanical balance of the car matters more at lower speeds because aero isn't as influential?

Perhaps a nervous and difficult car to drive at low speeds could be a very good car at mid to high speeds, and vice versa.
Saishū kōnā

MoP
MoP
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Joined: Tue May 23, 2017 4:50 pm

Re: Ferrari SF21

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https://www.motorsport.com/f1/video/the ... 39/138406/

I will just leave this here on topic of 'mechanical grip. It should still be valid. Mechanical grip in a nutshell ist just getting all the tires to work properly.

marcush
marcush
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Joined: Sat Mar 27, 2021 6:26 pm

Re: Ferrari SF21

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AR3-GP wrote:
Tue Jul 13, 2021 7:03 pm
marcush wrote:
Tue Jul 13, 2021 9:02 am
what is mechanical grip in an aerodominant environment ?
We should never forget , all downforce generated serves one (!)single purpose :
generating mechanical grip.
why does it generate generate grip ?
because the tyres grip level is vertical load sensisitive (more load =more grip)
The idea of generating the same amount of grip with less downforce is not a valid concept ,period.Reduce downforce and your grip potential diminishes .
Of course tyre grip is also temperature sensitive and you got surface temp as well as core (construction temps) , the generation of temps a function of how you work the tyres .
There is a line of thought in F1 more or less ignoring the mechanical side of wheel motion geometric control .
we saw impossible wishbone angles for aero reasons ,we still see brutally restrained vertical motion at the front for aero reasons .
I think you are jumbling up concepts. Mechanical and aerodynamic grip are two different things. They act together. One on top of the other. The importance of one vs the other changes as a function of speed.

Mechanical grip is a function of chassis stiffness, spring and damper rates, center of gravity, load transfer, and how well the chassis applies it's own weight consistently over the 4 contact patches. Aero is simply additive.

For example, you can have a car with a very high center of gravity. Load will transfer from front to rear and side to side much more aggressively meaning a wheel is unloaded excessively which lowers your braking and low speed cornering potential. Similarly, poor ride compliance through a corner on a bumpy circuit leads to a low normal force at the contact patch. Optimizing these chassis parameters increases mechanical grip. Optimizing aerodynamics increases aerodynamic grip.

I don't think semantics is of value here. Yes the aerodynamic loads must act through the tire, but aerodynamic loads in the absence of a change in the vehicle pitch,roll, yaw, are not affected by load transfer. Mechanical grip is. To some extent, aerodynamics are always turned on, but the importance of aero diminishes at very low speeds.
All your "Aerogrip"has to go through the tyre ,and thus is translated to mechanical grip , thats undisputable fact :all grip forces go through the tyre .

again :tyre vertical force (dynamic weight +downforce ) determines the grip a tyre can generate .The more vertical force the more grip potential is available
So its nonsense to think you could decide how you generate grip.reducing downforce your grip level is lower , simple as that.

I'm not saying the mechanical is unimportant (as Frank Dernie said back in his time in F1) but to be anything near competitive in F1 you need to exploit your resources fully.There is no way you can setup a car with aerodynamics considered as a "add"on .Aero acts as a
mechanical force , compressing springs , moving loads in your mechanical setup
and at most racing speeds eg above 100km/h becomes dominant force in the equation .You still need your damping and roll stiffness under control
but your driving factor becomes aeroplatform control .Of course you still
have to work on keeping the tyre from bouncing , you still need a constant contact patch .

Looking at tyre sensitivity to vertical load
this is a law of diminishing returns .So for every Pound of downforce added you
get less and less grip added ..so adding downforce has to be balanced against drag here .
And with variing speeds you will inevitably have to compromise your setup for best performance in the most relevant corners or for straght line speed.But thats another story .

marcush
marcush
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Re: Ferrari SF21

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godlameroso wrote:
Wed Jul 14, 2021 1:00 am
Could it be possible to say that mechanical balance of the car matters more at lower speeds because aero isn't as influential?

Perhaps a nervous and difficult car to drive at low speeds could be a very good car at mid to high speeds, and vice versa.
yes of course , you can also claim that a car wich is tail happy at lower speeds only and migrates towards understeer
with rising speed and bigger corner radii
is a good development direction.
You still need to make use of the extra grip downforce will produce.


Still you can't ignore the fact you need to
meet certain drag level targets , otherwise you will be easy prey on the straights .
This is compounded by DRS availability
in race different to practise and qualy .
Youcan shed drag a lot more in not race cicumstances .but you cannot ignore the need to not sacrifice everything for grid position.

Sevach
Sevach
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Re: Ferrari SF21

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Image

No Spa style wing this season.

Also a good look on the latest version of the floor (raced in Austria).

Manfer
Manfer
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Joined: Sat Feb 14, 2015 5:45 am

Re: Ferrari SF21

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Sevach wrote:
Thu Jul 15, 2021 8:02 pm
https://pbs.twimg.com/media/E6W8sbYX0AE ... name=large

No Spa style wing this season.

Also a good look on the latest version of the floor (raced in Austria).
Looks the vanes around the air box are new.

Sevach
Sevach
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Joined: Thu Jun 07, 2012 4:00 pm

Re: Ferrari SF21

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Manfer wrote:
Thu Jul 15, 2021 8:06 pm
Sevach wrote:
Thu Jul 15, 2021 8:02 pm
https://pbs.twimg.com/media/E6W8sbYX0AE ... name=large

No Spa style wing this season.

Also a good look on the latest version of the floor (raced in Austria).
Looks the vanes around the air box are new.
The "horns" have been there all year, can't say i see a change.
It's designed in that fashion, cut-out in the lower portion, to be "camera ready".

Manfer
Manfer
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Joined: Sat Feb 14, 2015 5:45 am

Re: Ferrari SF21

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Sevach wrote:
Thu Jul 15, 2021 8:11 pm
Manfer wrote:
Thu Jul 15, 2021 8:06 pm
Sevach wrote:
Thu Jul 15, 2021 8:02 pm
https://pbs.twimg.com/media/E6W8sbYX0AE ... name=large

No Spa style wing this season.

Also a good look on the latest version of the floor (raced in Austria).
Looks the vanes around the air box are new.
The "horns" have been there all year, can't say i see a change.
It's designed in that fashion, cut-out in the lower portion, to be "camera ready".
You are right, I thought the cutout was new, but they have been always like that.

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gordonthegun
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Location: Gorgonzola (Milan), Italy.

Re: Ferrari SF21

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Image

Image

ryaan2904
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Joined: Thu Oct 01, 2020 8:45 am

Re: Ferrari SF21

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AR3-GP wrote:
Tue Jul 13, 2021 7:03 pm
marcush wrote:
Tue Jul 13, 2021 9:02 am
what is mechanical grip in an aerodominant environment ?
We should never forget , all downforce generated serves one (!)single purpose :
generating mechanical grip.
why does it generate generate grip ?
because the tyres grip level is vertical load sensisitive (more load =more grip)
The idea of generating the same amount of grip with less downforce is not a valid concept ,period.Reduce downforce and your grip potential diminishes .
Of course tyre grip is also temperature sensitive and you got surface temp as well as core (construction temps) , the generation of temps a function of how you work the tyres .
There is a line of thought in F1 more or less ignoring the mechanical side of wheel motion geometric control .
we saw impossible wishbone angles for aero reasons ,we still see brutally restrained vertical motion at the front for aero reasons .
I think you are jumbling up concepts. Mechanical and aerodynamic grip are two different things. They act together. One on top of the other. The importance of one vs the other changes as a function of speed.

Mechanical grip is a function of chassis stiffness, spring and damper rates, center of gravity, load transfer, and how well the chassis applies it's own weight consistently over the 4 contact patches. Aero is simply additive.

For example, you can have a car with a very high center of gravity. Load will transfer from front to rear and side to side much more aggressively meaning a wheel is unloaded excessively which lowers your braking and low speed cornering potential. Similarly, poor ride compliance through a corner on a bumpy circuit leads to a low normal force at the contact patch. Optimizing these chassis parameters increases mechanical grip. Optimizing aerodynamics increases aerodynamic grip.

I don't think semantics is of value here. Yes the aerodynamic loads must act through the tire, but aerodynamic loads in the absence of a change in the vehicle pitch,roll, yaw, are not affected by load transfer. Mechanical grip is. To some extent, aerodynamics are always turned on, but the importance of aero diminishes at very low speeds.
Very well said!!

marcush
marcush
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Re: Ferrari SF21

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I leave it at that : its the,reason why teams struggle with finding setup compromises , because you need to have the car in a certain aero window so
you load the tyres enough to get the most out of the tyres.
you may find local peaks of performance
simply by being able to generate a good
dynamic balance for your driver , but this is incredibly difficult to maintain over a stint , race or through change of conditions .
In an ideal world you would design and,setup the car to not be upset by
changes of fuelload , track and ambient temperatures ,eg create a robust system .obviously this is not a realistic scenario.

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codetower
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Re: Ferrari SF21

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Question regarding the tyre degradation issues in the SF21: The team say they still haven't solved the issue, yet the car/tyres seem to be performing much better since France. Have the drivers made any significant changes to their driving styles to help with the tyres? If the team hasn't "fixed" the problem, they definitely have improved it quite a bit.