Aero grip vs. mechanical grip (and low profile tires)

[hollus]

“I think in general what we need to follow another car closer in medium speed, high speed, slow speed corners is more mechanical grip. So shift the percentage between aero/mechanical more towards more mechanical. How to do that? I think we need better tyres that allow us to go quicker.”

This got me wondering if anther way to shift the percentage "aero/mechanical" more towards mechanical couldn't be the shift to low profile tires. Right now teams are stuck with several inches of black rubber that effectively act like a mechanical spring in series with the rest of the suspension, only a spring that they can only partially control, which changes behavior with temperature, and whose setup has to be sacrificed in favor of the ideal contact patch. They also get two different versions of it during each race, and sometimes the FIA forces them to run with the blue or green painted version.
Low profile tires have a much smaller version of this rubbery spring.
If that is removed or at least reduced, teams would have to increase suspension travel and possibly suspension complexity, but this suspension element would now be under their control, temperature insensitive and tuned for its proper purpose.
What does everyone think, would moving this big, bulky, rubbery black spring to the inside of the car, where it would look like a coil, a flexure and/or a damper help to increase the percentage of mechanical vs aero based grip?

[NL_Fer]

Pirelli actually proposed 18" low height tyres, but the teams didn't want to. They would have to redesign the car from scratch. It would cost to much money. The current suspension cannot be modded to take over the role of current tyres.

Btw in the past, close racing was not possible due the lost aero and turbulence from the leading car. Now with lowered aero, the tyres already need to work harder, and close racing overheats them, same for the brakes.

[Tim.Wright]

In my opinion reducing the tyre compliance will just allow the team's to run lower ride heights and greatly increase the downforce coming from the floor. I'd say the big bouncy springs we have now between the rim and the track are forcing the cars to be run higher than desired and limiting the effectiveness of the floor.

As a concept, replacing the aerodynamic grip (mu x rho x Cz x S x Vel^2 / 2) with mechanical grip (mu x mass x g) is not so easy. The aero currently adds several G's worth grip whereas the tyres are only responsible for about 1.6G. Better tyres might eek out an extra 0.2-0.3g but that's about it. Aero grip is relatively easy to add or subtract by modifying the regulations.

I have to say, I find it pretty piss weak that the team's complain about redesigning the suspension for 18" tyres. It seems they have forgotten how to design stuff any more - they just like optimising what they have. Honestly, if it's too much work for them to design a cookie cutter passive double wishbone suspension then the sport has taken a wrong turn somewhere...

[mrluke]

The only teams that complain about the redesign are those who think they are doing a good job at the moment, I. E. There is a risk they won't do as good a job compared to the opposition if they have to redesign.

Costs is rubbish, it's just a buzzword they are using to get the change rejected.

Fundamentally Tims point above is spot on, mechanical grip is at the very most 30 to 40% if the total and unable to be increased without reducing overall grip considerably.

[Vyssion]

As a concept, replacing the aerodynamic grip (mu x rho x Cz x S x Vel^2 / 2) with mechanical grip (mu x mass x g) is not so easy. The aero currently adds several G's worth grip whereas the tyres are only responsible for about 1.6G. Better tyres might eek out an extra 0.2-0.3g but that's about it. Aero grip is relatively easy to add or subtract by modifying the regulations.

I have to say, I find it pretty piss weak that the team's complain about redesigning the suspension for 18" tyres. It seems they have forgotten how to design stuff any more - they just like optimising what they have. Honestly, if it's too much work for them to design a cookie cutter passive double wishbone suspension then the sport has taken a wrong turn somewhere...

Pretty much sums it up as I would've put it. I think that the tyres would add a bit more maximum lateral acceleration, but I would hazard a guess, that most (if not a fair proportion) of that would come from the suspension redesign needed to take full advantage of them.

I remember attending a conference with Willem Toet last year and someone in the audience asked him about this. His reply was that, with regards to aero, if the regulations allowed, they could more than double the downforce overnight; mechanical grip is much harder since there was one variable element (i.e. the tyre) upon which the mechanical system was designed in order to 'hopefully' put the optimum operating range of the tyre around about the current chassis configuration.

Sometimes I wish that there was a "Formula Unlimited" series, like in rally where everything is just stupidly over the top and we get to see what really can be done with a car... ah well, one can dream!!

[Facts Only]

Sometimes I wish that there was a "Formula Unlimited" series, like in rally where everything is just stupidly over the top and we get to see what really can be done with a car... ah well, one can dream!!

There pretty much is, go to a hillclimb.

I love this picture (isnt No. 59 Willem Toaet car)

[riff_raff]

Sometimes I wish that there was a "Formula Unlimited" series, like in rally where everything is just stupidly over the top and we get to see what really can be done with a car... ah well, one can dream!!

Stupidly over the top....that's the Pike's Peak unlimited class. You can run any combination of engine, chassis, drivetrain, aerodynamics, suspension, wheels, tires, brakes, etc you want to. The circuit and conditions are also very challenging.

[DaveW]

If that is removed or at least reduced, teams would have to increase suspension travel and possibly suspension complexity, but this suspension element would now be under their control, temperature insensitive and tuned for its proper purpose.
What does everyone think, would moving this big, bulky, rubbery black spring to the inside of the car, where it would look like a coil, a flexure and/or a damper help to increase the percentage of mechanical vs aero based grip?

For what it is worth, vertical tyre stiffness (in N/mm) measured on a rig were as follows:

F4 : 219/250
GP3 : 250/289
GP2 : 284/336
FE : 325/371
F1 : 340/463

Which were the low profile tyres...?

[Pierce89]

Sometimes I wish that there was a "Formula Unlimited" series, like in rally where everything is just stupidly over the top and we get to see what really can be done with a car... ah well, one can dream!!

There pretty much is, go to a hillclimb.

I love this picture (isnt No. 59 Willem Toaet car)
http://britishhillclimb.co.uk/wp-conten ... 294_tn.jpg

Yes the 59 is the Empire Wraith with aero by Toet.

[andylaurence]

Sometimes I wish that there was a "Formula Unlimited" series, like in rally where everything is just stupidly over the top and we get to see what really can be done with a car... ah well, one can dream!!

Yes, hillclimbs and sprints. I'm limited by a maximum width of 1500mm ahead of the front wheels (and below the height of the front wheel rim), 1400mm behind the front wheels and no more than 1500mm behind the rear wheels. Quite a build envelope. Want to flex your MSc muscles?

[Sevach]

For mechanical grip bigger tires and wider tracks are coming, but aero is getting a bump as well so who knows.

I would've liked if they went for something like 16 inch wheels, you don't get the sense on tv but in person the current F1 tire looks like something from a mini dragster.

[SuperDrummer]

If that is removed or at least reduced, teams would have to increase suspension travel and possibly suspension complexity, but this suspension element would now be under their control, temperature insensitive and tuned for its proper purpose.
What does everyone think, would moving this big, bulky, rubbery black spring to the inside of the car, where it would look like a coil, a flexure and/or a damper help to increase the percentage of mechanical vs aero based grip?

For what it is worth, vertical tyre stiffness (in N/mm) measured on a rig were as follows:

F4 : 219/250
GP3 : 250/289
GP2 : 284/336
FE : 325/371
F1 : 340/463

Which were the low profile tyres...?

FE are the lowest profile, the next one should be F4.
But we should remember that you need to cope with maximum 500-600 N of downforce per wheel. F1 loads are several times higher.

[ringo]

What can be achieved with 4 wheel steering?

I believe F1 need to get back to active suspension if we really are to see an improvement with following another car.

So these areas: 4 wheel steering, active suspension, (active aero maybe as well?) should be on the table.


https://www.youtube.com/watch?v=GvQh2ue--0g

[Cold Fussion]

Would probably be helpful for low speed understeer since the wheel base on today's cars is quite long.

[Tim.Wright]

4 wheel steering is more of a stability thing (by artificially increasing rear axle cornering stiffness) rather than a grip peformance thing. You can't really increase the rear axle grip by playing with the toe angles.

It might make things slightly quicker in that by increasing the stability could allow the driver to run an otherwise less stable setup. But it's a lot of effort and weight for a very small benefit in my opinion.

Also, in my opinion, more stability is the last thing we need now. The drivers are already cruising around so slowly (for tyre conservation) that the cars are so far from the limit. So they already have too much stability margin and its why we practically never see driver's make mistakes anymore.