Understeer ... the good, the bad & the Technical

A place to discuss the characteristics of the cars in Formula One, both current as well as historical. Laptimes, driver worshipping and team chatter do not belong here.
venkyhere
venkyhere
13
Joined: 10 Feb 2024, 06:17

Re: Ferrari SF-24

Post

I believe the prime benefit of flexi front wings is not 'reduced drag'. Reduced drag in a straight line at high speed, is a secondary benefit that. The prime benefit, according to me is in high speed corners. The FW flexes, reduce the front downforce, shifts the center of pressure rearwards in the car "automatically" and introduces understeer. That's what the driver wants in a long radius high speed corner. In slower corners, no FW flex, high downforce in the nose => helps rotate the car faster. This 'dynamic balance change to suit different types of corners' is the real benefit of a flexi FW.

venkyhere
venkyhere
13
Joined: 10 Feb 2024, 06:17

Re: Ferrari SF-24

Post

Emag wrote:
20 Sep 2024, 14:24
venkyhere wrote:
20 Sep 2024, 07:23
I believe the prime benefit of flexi front wings is not 'reduced drag'. Reduced drag in a straight line at high speed, is a secondary benefit that. The prime benefit, according to me is in high speed corners. The FW flexes, reduce the front downforce, shifts the center of pressure rearwards in the car "automatically" and introduces understeer. That's what the driver wants in a long radius high speed corner. In slower corners, no FW flex, high downforce in the nose => helps rotate the car faster. This 'dynamic balance change to suit different types of corners' is the real benefit of a flexi FW.
There is no scenario where any driver would want to induce understeer mid corner, except to counteract snap oversteer. Understeer is especially hurtful on a long radius corner that you take as an example here.

The benefit of flexing wings comes from the fact that you can run with a lot more load at the front, without a drag penalty which would otherwise nullify the advantages in (certain) corners with losses on the straights.
Probably the word 'understeer' was the culprit. And I didn't mean that the car would suddenly become understeery mid-corner, after entering with neutral balance. I mean 'introduce a bit of understeer by removing a bit of DF from front => shift the balance more towards rear' - didn't mean the car has understeer w.r.t a neutrally balanced car. No.
For slow and medium corners, a fast F1 car has to be sharp on it's nose, especially for small radius corners, because you want the car to 'rotate' quickly.
For fast long radious corners, if the car has the same front wing level, due to the extreme speed, the front DF will grow to become too much, so much that snap oversteer is highly likely. So if there is a way to 'on the fly' reduce the front wing level, the front DF wont grow to monstrous levels so as to make the car highly sensitive to yaw (a slight noise input from driver's hand muscles, a slight gust of wind etc). The total front DF would still be higher than the slow and medium corners, when the front wing 'reduces' ; but the 'balance' of the car would shift rearwards, reducing the sensitivity of the car to snap. The 'balance shift' would start even before corner entry as the entry is happening at high speed. So no 'mid-corner' change as you mentioned.

Andi76
Andi76
426
Joined: 03 Feb 2021, 20:19

Re: Ferrari SF-24

Post

Emag wrote:
20 Sep 2024, 14:24
venkyhere wrote:
20 Sep 2024, 07:23
I believe the prime benefit of flexi front wings is not 'reduced drag'. Reduced drag in a straight line at high speed, is a secondary benefit that. The prime benefit, according to me is in high speed corners. The FW flexes, reduce the front downforce, shifts the center of pressure rearwards in the car "automatically" and introduces understeer. That's what the driver wants in a long radius high speed corner. In slower corners, no FW flex, high downforce in the nose => helps rotate the car faster. This 'dynamic balance change to suit different types of corners' is the real benefit of a flexi FW.
There is no scenario where any driver would want to induce understeer mid corner, except to counteract snap oversteer. Understeer is especially hurtful on a long radius corner that you take as an example here.

The benefit of flexing wings comes from the fact that you can run with a lot more load at the front, without a drag penalty which would otherwise nullify the advantages in (certain) corners with losses on the straights.
What you say is not quite true. Of course a driver doesn't like extreme understeer. But in fast corners, an understeering balance is definitely preferred, as is a slightly oversteering balance in slow corners. It is therefore quite correct that the main aim of the flexible wings is to "adjust" the aerodynamic balance accordingly. In slow corners you want more "front bite" and a little more downforce at the front, while in fast corners the aerodynamic balance should move slightly towards the rear. No driver wants a car that constantly threatens to break out at the rear at 300 km/h.

Farnborough
Farnborough
95
Joined: 18 Mar 2023, 14:15

Understeer ... the good, the bad & the Technical

Post

As a destination for the interesting discussion going on in Ferrari SF24 thread, hopefully to encourage continued debate and examinatory contribution.

I think it should be most specifically about this trait in high speed, high torque/throttle application, avoiding the intricacies of low corner speed dynamics for clarity of topic.

Farnborough
Farnborough
95
Joined: 18 Mar 2023, 14:15

Re: Ferrari SF-24

Post

I too felt it interesting discussion and worthy of forum input.

Hopefully the content can be moved to here viewtopic.php?t=31911 and continue.

Greg Locock
Greg Locock
234
Joined: 30 Jun 2012, 00:48

Re: Understeer ... the good, the bad & the Technical

Post

What definition of understeer are you using?

Tommy Cookers
Tommy Cookers
632
Joined: 17 Feb 2012, 16:55

Re: Understeer ... the good, the bad & the Technical

Post

Farnborough wrote:
27 Sep 2024, 18:00
,,, I think it should be most specifically about this trait in high speed, high torque/throttle application, avoiding the intricacies of low corner speed dynamics for clarity of topic.
Maurice Olley would have agreed with that

in slow corners accelerations in yaw are large - so dynamic 'understeer' significantly leads steady state steer behaviour

Farnborough
Farnborough
95
Joined: 18 Mar 2023, 14:15

Re: Understeer ... the good, the bad & the Technical

Post

Greg Locock wrote:
27 Sep 2024, 19:46
What definition of understeer are you using?

Thought I'd exclude slow discussion (as it reduces the need to involve long comparison) but see what is understood by other observers of F1 in regard to how that would be interpreted.

Blunt view would be exaggerated "armful" of lock with vehicle travelling straight on, nuance would need far far more refinement of description and better resolution, to align with what the drivers are doing.

I know what I think and have experienced, that in kart, rally, road car, motorcycle both on and off road there's manifestation of it and driving with it to good and poor effect.

Technically, it could be defined by the wheel spindle trajectory being directed in tighter radius than that which the wheel is following, to ultimately bring the vehicle path below tbat requested.

But in high torque high speed, with rear lateral movement giving yaw to chassis, then with fronts effectively running straight (steering wheel not turned) but gradually moving to wider radius overall .... is that under or over steer .... or the two technically balanced ? Thinking in track terms of 2nd 1/3 Parabolica at Monza to give example.

What do you think, and how would that be described ?

Sevach
Sevach
1076
Joined: 07 Jun 2012, 17:00

Re: Understeer ... the good, the bad & the Technical

Post

No one wants understeer they want stable, and what feels stable to some drivers will feel like understeer for others.

I've read a comparison between Hamilton and Button during their Mclaren years, by one of their chief technicians, with how you have to optimize the car for the whole lap, the team could put more front in the car for Hamilton because he would be able to deal with the rear at it's critical points, no complaints whatsover with a setup Button would call undriveable.
And then in tighter corners where a car that rotates faster is beneficial Hamilton would profit.

AR3-GP
AR3-GP
364
Joined: 06 Jul 2021, 01:22

Re: Understeer ... the good, the bad & the Technical

Post

Some drivers confuse understeer for pushing a car faster than the downforce it produces will allow.

If you drive at 200mph and attempt to turn for the first chicane at Monza, you will "understeer"....This is not an "understeer" problem. This is simply going too fast for the corner. There is a reason that the cars have brakes.
A lion must kill its prey.