Advantages (and disadvantages) of looooooonger cars

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hollus
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Advantages (and disadvantages) of looooooonger cars

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In the last few years we have seen cars getting longer and longer. Obviously the designers think that longer is faster.
So which factors work in favor (and against) a longer car achieving better lap times?
I'll start with a simple list of what comes to my head, but I am sure I'll get a couple at least half wrong an miss many:

Advantages:
  • More floor surface to generate underfloor downforce.
  • More distance from the front tires to key aero surfaces, allowing for the turbulence to dissipate to some extent.
  • More distance from the front tires to key aero surfaces, allowing for the turbulence to be easier to push outboard.
  • More distance (cleaner flow) between airbox and rear wing.
  • More real state to add air controlling elements.
  • Possibility for a slimmer read end, allowing for a cleaner flow in the diffuser area.
  • Less front/rear weight transfer under acceleration/braking.
  • More space to move elements around to control the center of gravity longitudinally.
  • More space to place things lower to control the center of gravity vertically.
  • Is it easier to accommodate taller drivers?
  • And finally, cheekily and very much second or third order: A few extra cm needed for others to complete an overtake.
Disadvantages:
  • More weight simply to cover the length of the car. Even with a weight limit, this means less ballast to play with.
  • Even more weight to maintain torsional rigidity in a longer car. Alternatively loss of rigidity.
  • There is more floor length to seal to maintain underfloor downforce.
  • Less extra wing angle with rake as the possible rake angles are diminished.
  • Does one effectively tighten the corners by a few centimeters?
  • Does one need to turn the wheels at a higher angle to achieve the same car yaw? does this disrupt aero?
  • And finally, cheekily and very much second or third order: A few extra cm needed for you to complete an overtake.
I am assuming that the extension happens mostly behind the driver, and that the driver is still placed as much forward as possible, but is this correct?
I am discounting a lazier car for turning. Longer (lazier) is better in open corners and worse in tight corners, isn't it?
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Just_a_fan
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Re: Advantages (and disadvantages) of looooooonger cars

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Simplified as: it's the fastest way around a race track with the current rules. :lol:
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hollus
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Re: Advantages (and disadvantages) of looooooonger cars

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Oh, yes. Current rules are key. I don't think the cars would be long if the minimum weight didn't implicitly allow for it. But they do.
Imagine a 900kg minimum weight rule. Would we have 7m cars?
"For every complex problem there is an answer that is clear, simple and wrong." H. L. Mencken
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Big Tea
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Re: Advantages (and disadvantages) of looooooonger cars

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It may be just a personal thing, but to me it always looks as if a bigger car is going slower. Not only due to relative positions etc but a more nimble car moves in a more 'darting' fashion and looks as if it is working harder.
I also know the opposite is true, but I know which I prefer to watch, especially on tv.
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Rodak
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Re: Advantages (and disadvantages) of looooooonger cars

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More space to move elements around to control the center of gravity longitudinally.
Are you aware that front/rear weight is controlled by regulation?
4.2 Weight distribution :
The weight applied on the front and rear wheels must not be less than the weight specified in
Article 4.1 factored by 0.455 and 0.535 respectively at all times during the qualifying practice
session. Rounding will be to nearest 0.5kg.
I don't like this rule, but the teams seem okay with it.

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jjn9128
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Re: Advantages (and disadvantages) of looooooonger cars

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Rodak wrote:
Sat May 16, 2020 4:16 pm
More space to move elements around to control the center of gravity longitudinally.
Are you aware that front/rear weight is controlled by regulation?
4.2 Weight distribution :
The weight applied on the front and rear wheels must not be less than the weight specified in
Article 4.1 factored by 0.455 and 0.535 respectively at all times during the qualifying practice
session. Rounding will be to nearest 0.5kg.
I don't like this rule, but the teams seem okay with it.
That rule exists to stop teams doing what the Nissan GTR-LM did and move a load of mass forward to maximize the potential of the front wing - which has been historically less restricted than the rear of the car in the regs. i.e. they've been under the peak potential of the front wing because they couldn't balance that downforce at the car at the rear. But they can play with the masses - the longer the car gets the more they can subtly move things about to achieve the prescribed COG.


On the OP it's alllllll about the downforce. Kinematics and stability maybe have a say but the key to laptime is downforce. Aerodynamically there's a bit of an efficiency gain because they can fish tail (coke bottle) the rear more, but downforce is the big thing pretty much for all the reasons you stated.
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Tim.Wright
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Re: Advantages (and disadvantages) of looooooonger cars

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The rule on the mass distribution was brought in for the first year of the switch to Pirelli to stop anyone getting an advantage by fluking out on the correct optimum mass distribution.

A long car, with other things equal, will be more damped and have more yaw inertia both of which make a car less agile - but here all things are not left equal. Longer cars mean more downforce, and more downforce means higher cornering stiffness on the front and rear axles which will then reverse these effects which reduce agility and you will likely end up with a net increase of agility due to the downforce.
Not the engineer at Force India

gruntguru
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Re: Advantages (and disadvantages) of looooooonger cars

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Wheelbase and polar moment of inertia are key to agility.
Polar moment is the inertia which resists yaw.
Wheelbase x Fy provides the yaw moment to rotate the car.

So extending wheelbase improves agility provided polar moment doesn't increase by the same percentage.

Yaw and Pitch stability is another benefit of extended wheelbase.

Having said all that - is wheelbase regulated? :D
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Rodak
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Re: Advantages (and disadvantages) of looooooonger cars

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I just reread the regulations and to my amazement could find no reference to a wheel base limit. The only thing related to that is overhang from the front and rear wheel centerlines. There is no length limit, unless I'm blind.
3.2.3
Overhangs
No part of the car may be more than 810mm behind the rear wheel centre line or more than 1225 mm in front of the front wheel centre line.
I guess we can learn something every day.

Ringleheim
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Re: Advantages (and disadvantages) of looooooonger cars

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gruntguru wrote:
Sun May 17, 2020 11:25 pm
Wheelbase and polar moment of inertia are key to agility.
Polar moment is the inertia which resists yaw.
Wheelbase x Fy provides the yaw moment to rotate the car.

So extending wheelbase improves agility provided polar moment doesn't increase by the same percentage.

Yaw and Pitch stability is another benefit of extended wheelbase.

Having said all that - is wheelbase regulated? :D
I was going to mention something along these lines, which was missed in the OP.

Biggest advantage to the long cars, perhaps aside from more aero surface area, is greater cornering force due to lengthened wheelbase.

As an aside: I'd like to say that the cars now are GIGANTIC and I really dislike this era of F1 for many reasons.

Go back and watch a race from the '90s or 2000s...the cars look tiny in comparison.

ENGINE TUNER
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Re: Advantages (and disadvantages) of looooooonger cars

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With wider cars, longer car will generally decrease drag.

Most of the longer wheel base occurs from the clutch to the rear axle. I don't think most of the cars have creased the distance from the front axle to the leading front edge of the floor.