F1 suspension setup change question

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firasf1dream
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Joined: 18 Apr 2014, 21:26

F1 suspension setup change question

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hello everyone,
I hope you are well

i would like please some explanation about the suspension setup change like camber and others and some default parameters. I will be referring to this picture below Image

1 - As we can see in the picture it says shims, so i would like to know are these shims for camber change or for Kingpin change ?
2 - for camber change, as we know that we must change the wishbones length for that ( i remember last year I asked a technician in redbull show how does he change the camber, he showed me the shims and said we add shims to where it says shims in the picture above, so i wonder if we add shims that will change the kingpin angle !

3 - when they design the upright, i saw that usually the above wishbone link comes in 2 pieces in which you can insert shims as we can see in the picture and for the bottom wishbone the connection point on the upright is built in and cannot change !

4 - we can see in the picture that the black piece for the upper wishbone connection and the upright arm has an angle with the wheel vertical center line , so i believe that is in the same line as the upper wishbone right ?

thank you in advance

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Tim.Wright
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Joined: 13 Feb 2009, 06:29

Re: F1 suspension setup change question

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The shims change the camber angle independently to the KPI because the shims are placed between the clevis and the upright (in other words between the upper ball joint and the upright). This also demonstrates that you don't need to change the wishbone lengths to change the camber.

These shims are typically only put on either the upper or lower arm but not both. This means that your scrub radius changes slightly with the camber adjustment but its not such a big deal.

The angle of the clevis is likely to centre the spherical joint about its angular range. Spherical bearings have limits to the angular range they can articulate (usually around 6-8deg for compact joints and upto 15deg for high misalignment joints) so to avoid running the joint out of its angular range the clevis is usually mor or less lined up with the wishbone in the static design position.
Not the engineer at Force India

firasf1dream
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Joined: 18 Apr 2014, 21:26

Re: F1 suspension setup change question

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Tim.Wright wrote:The shims change the camber angle independently to the KPI because the shims are placed between the clevis and the upright (in other words between the upper ball joint and the upright). This also demonstrates that you don't need to change the wishbone lengths to change the camber.

These shims are typically only put on either the upper or lower arm but not both. This means that your scrub radius changes slightly with the camber adjustment but its not such a big deal.

The angle of the clevis is likely to centre the spherical joint about its angular range. Spherical bearings have limits to the angular range they can articulate (usually around 6-8deg for compact joints and upto 15deg for high misalignment joints) so to avoid running the joint out of its angular range the clevis is usually mor or less lined up with the wishbone in the static design position.
thanks a lot Tim about the reply, but the only thing that i can not see how it doesn't affect the the KPI so i made a drawing below, it shows that the kingpin angle has changed according to the vertical because the shim is pushing the clevis therefore the joint point towards the car longitudinal center line or towards the outside because the wishbone length is fixed which changes the camber as well
Image

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Tim.Wright
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Joined: 13 Feb 2009, 06:29

Re: F1 suspension setup change question

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The shims don't push the clevis in, it pushes the upright out.
Not the engineer at Force India

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Tim.Wright
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Joined: 13 Feb 2009, 06:29

Re: F1 suspension setup change question

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P.S. undefined sketches make jesus cry
Not the engineer at Force India

firasf1dream
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Joined: 18 Apr 2014, 21:26

Re: F1 suspension setup change question

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Tim.Wright wrote:The shims don't push the clevis in, it pushes the upright out.
ah right ! i tried to visualize it, yes the wishbone same length, the upright as it is here parallel with the vertical it will be at an angle so the kingpin is with the vertical it will stay the same !
so about the camber it must be designed in its most negative angle right ?
Tim.Wright wrote:P.S. undefined sketches make jesus cry
hahaha you are right but this was a fast sketch just to show it :lol:

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strad
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Joined: 02 Jan 2010, 01:57

Re: F1 suspension setup change question

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Tim, Is it not very similar to the shims used to adjust camber on say a 1974 Ford?
Image
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Sir Stirling Moss

firasf1dream
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Joined: 18 Apr 2014, 21:26

Re: F1 suspension setup change question

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strad wrote:Tim, Is it not very similar to the shims used to adjust camber on say a 1974 Ford?
http://www.stradsplace.com/public_html/photos/shims.jpg
I had the chance last juin to see a redbull car show being disassembled, so i asked the technician about the camber adjustment, he showed me a shim, for the RB7, i remember it was rectangular with opening in the middle like the one you shared in the picture

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