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 .