3 shocks at the front.

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Caito
Caito
13
Joined: 16 Jun 2009, 05:30
Location: Switzerland

3 shocks at the front.

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[youtube]http://www.youtube.com/watch?v=j7KUdgwzKIM[/youtube]

I know spanish, so I can understand a little bit of italian. Still I couldn't understand what's the horizontal shock doing.

Does anybody know what's the purpose of the 3rd shock?


Thank you very much!


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DAC.-
Come back 747, we miss you!!

Mystery Steve
Mystery Steve
3
Joined: 25 Sep 2009, 07:04
Location: Cincinnati, OH, USA

Re: 3 shocks at the front.

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The third damper only provides damping when the suspension is in jounce (both wheels are going up, or down, at the same time). If used effectively, you can tune it so that the load variation at the contact patch is decreased. It also allows the designers to tune the damping for jounce versus roll somewhat independently. There was an article on J-dampers posted on this website a couple years ago:

http://www.f1technical.net/features/10586

The fundamental design of the damper in the article is different than the video, but it is used for the same purpose.

mx_tifoso
mx_tifoso
0
Joined: 30 Nov 2006, 05:01
Location: North America

Re: 3 shocks at the front.

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Aqui esta esto, espero que sea de ayuda...

:arrow: 3rd spring

:arrow: Third spring/damper


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Caito
Caito
13
Joined: 16 Jun 2009, 05:30
Location: Switzerland

Re: 3 shocks at the front.

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Thank you very much!

Am I wrong,or there's no anti-roll bar at the front?
Come back 747, we miss you!!

Carlos
Carlos
11
Joined: 02 Sep 2006, 19:43
Location: Canada

Re: 3 shocks at the front.

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Your right Caito, there's no anti-roll bar on the front suspension, anti-roll bars are no longer used on the front or rear suspension in F1.

Mystery Steve
Mystery Steve
3
Joined: 25 Sep 2009, 07:04
Location: Cincinnati, OH, USA

Re: 3 shocks at the front.

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Caito wrote: Am I wrong,or there's no anti-roll bar at the front?
There is no anti-roll bar shown in that video. The video shows three dampers and two torsion springs. Two of the dampers are connected to one side only and operate regardless of roll or heave. The third damper only works when the two wheels are moving in the same direction. The torsion springs are like the first two dampers and work all the time.

Thinking out loud here: I don't think the teams necessarily want anti-roll bars at the front. A major design point of the suspension is controlling a reasonable level of heave so that they can maintain the ride height and rake of the vehicle so as to minimize the downforce variation since the undertray is pitch- and ride height-sensitive. While they require this stiffness in heave, they don't necessarily want it in roll because the driver requires some feedback to control the car. Or at least that's my thoughts. It is a balance none the less.

I'm not sure about the rear end, though. I'm sure you saw the video I've posted below which shows a typical setup for the rear, as illustrated using the Brawn GP car from last year. There are two dampers; again, one for each wheel. There is also a third damper in the middle, that has a spring around it. This is called the heave spring, which is what knocked Felipe Massa out last year. This heave spring is actuated in the same way as the third damper at the front of the car. It only is actuated when the wheels are both moving the same direction. One thing I'm not sure on myself: is the component highlighted in yellow at around 0:40 an anti-roll bar, or is it just a pivot for the heave spring? In other words, is the lower end of the yellow-highlighted bar rigidly mounting at the bottom, or is there a ball joint of some kind? I would think it would have to act as a spring, otherwise there is no spring force in roll. The only control force is from the dampers in that case.

[youtube]http://www.youtube.com/watch?v=Z8W4oLZY ... re=related[/youtube]

Oh, and I hope Brawn's rod ends didn't actually have that much slop...

autogyro
autogyro
53
Joined: 04 Oct 2009, 15:03

Re: 3 shocks at the front.

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I notice that Brawn did not want anyone to see the other two springs fitted to each shock. It would be possible to estimate the spring rate then of course.

Just_a_fan
Just_a_fan
593
Joined: 31 Jan 2010, 20:37

Re: 3 shocks at the front.

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Mystery Steve wrote:
Caito wrote: Am I wrong,or there's no anti-roll bar at the front?
One thing I'm not sure on myself: is the component highlighted in yellow at around 0:40 an anti-roll bar, or is it just a pivot for the heave spring?
Yes, the yellow item at 0.40 is the anti-roll bar.
If you are more fortunate than others, build a larger table not a taller fence.

Just_a_fan
Just_a_fan
593
Joined: 31 Jan 2010, 20:37

Re: 3 shocks at the front.

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autogyro wrote:I notice that Brawn did not want anyone to see the other two springs fitted to each shock. It would be possible to estimate the spring rate then of course.
The other two shocks don't have coil springs fitted. It's a torsion bar suspension - the spring is provided by the torsion bar running from the bell crank pivot down in to the gearbox housing.
If you are more fortunate than others, build a larger table not a taller fence.

marcush.
marcush.
159
Joined: 09 Mar 2004, 16:55

Re: 3 shocks at the front.

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Just_a_fan wrote:
Mystery Steve wrote:
Caito wrote: Am I wrong,or there's no anti-roll bar at the front?
One thing I'm not sure on myself: is the component highlighted in yellow at around 0:40 an anti-roll bar, or is it just a pivot for the heave spring?
Yes, the yellow item at 0.40 is the anti-roll bar.
BUT it works only as a torsion spring if the bar on top-the piece the dampers are mounted to) is mounted rigidly to the yellow bar!
So you could have both :a bearing mounted to allow it free svielling =no arb just a
means of activating third spring OR an ARB depending on assembly installation stiffness ...

Mysticf1
Mysticf1
0
Joined: 29 Jan 2010, 17:20

Re: 3 shocks at the front.

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I thought the main objective of the 3rd damper was to isolate downforce from the suspension allowing much softer springs.

marcush.
marcush.
159
Joined: 09 Mar 2004, 16:55

Re: 3 shocks at the front.

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Mysticf1 wrote:I thought the main objective of the 3rd damper was to isolate downforce from the suspension allowing much softer springs.

the idea is to isolate single bump behavoiur from heave behaviour and of course to add spring force with downforce .

autogyro
autogyro
53
Joined: 04 Oct 2009, 15:03

Re: 3 shocks at the front.

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Just_a_fan wrote:
autogyro wrote:I notice that Brawn did not want anyone to see the other two springs fitted to each shock. It would be possible to estimate the spring rate then of course.
The other two shocks don't have coil springs fitted. It's a torsion bar suspension - the spring is provided by the torsion bar running from the bell crank pivot down in to the gearbox housing.
Agreed, but why have spring platforms on the twin shocks in that case?

RacingManiac
RacingManiac
9
Joined: 22 Nov 2004, 02:29

Re: 3 shocks at the front.

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Carlos wrote:Your right Caito, there's no anti-roll bar on the front suspension, anti-roll bars are no longer used on the front or rear suspension in F1.
Somehow I doubt that. Granted they have a ton of spring rate for the cars, I find it hard to believe they would leave out a huge component for chassis tuning....

Just_a_fan
Just_a_fan
593
Joined: 31 Jan 2010, 20:37

Re: 3 shocks at the front.

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autogyro wrote:
Just_a_fan wrote:
autogyro wrote:I notice that Brawn did not want anyone to see the other two springs fitted to each shock. It would be possible to estimate the spring rate then of course.
The other two shocks don't have coil springs fitted. It's a torsion bar suspension - the spring is provided by the torsion bar running from the bell crank pivot down in to the gearbox housing.
Agreed, but why have spring platforms on the twin shocks in that case?
I wondered that too. Might just be an error on the part of the graphic artist who made the animation. Either way, All of the teams use torsion bars front and rear. Coil springs (where used at all) are restricted to the third spring.
If you are more fortunate than others, build a larger table not a taller fence.