the distance between the wishbones and knuckle height ?
the distance between the wishbones and knuckle height ?
(OP)
How the distance between upper and bottom wishbone is important. I design 3D model of tilt light car and I have problem with 3d model because I can't place the top front wishbone high. In technical view and dynamic aspect, what's happen if I place the top front wishbone lower, decrease its width and position knuckle asymmetric in the wheel, how much knuckle could be position low inside in the wheel.





RE: the distance between the wishbones and knuckle height ?
I think it could be argued that more closely balljoints are positioned, the bigger forces acting on wishbones will be. And I would think that all the camber/KPI/Caster/&c changes get more exaggerated with closely spaced ball joints.
* I don't know where I remember it from, but I also have a recollection of figure of something like 2/3 of wheel dia being mentioned in literaure as ballpark/target figur for distance between outer ball joints
HTH (as an appetiser before knowledgeable members join in)
RE: the distance between the wishbones and knuckle height ?
RE: the distance between the wishbones and knuckle height ?
The loading on the ball joints will be higher than with the arms higher up. What's stopping you from having the upper arm higher - to the point of having the upper arm outside the wheel as Honda and several others do?
RE: the distance between the wishbones and knuckle height ?
Regards
Pat
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RE: the distance between the wishbones and knuckle height ?
There undoubtedly are advantages in placing the upper ball joint above the tire, but there are disadvantages as well (practical, not kinematic). We call those long spindle SLAs.
There is also a bit of a trend towards mid length SLAs, where the upper ball joint is alongside the tire. Obviously you tend to run a lot of KPI in that case, but other than that it seems to work fine.
Finally if you are really in trouble you could use a virtual upper ball joint as Audi do. That introduces complexity into your kinematics, increases cost and weight, and steering friction, but gives you a lot more freedom for KPI and scrub radius in particular.
Cheers
Greg Locock
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RE: the distance between the wishbones and knuckle height ?
The trend to bigger dia wheels with more negative offset must open up the space to get the ball joints further apart with a low king pin inclination while inside the wheel
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
RE: the distance between the wishbones and knuckle height ?
RE: the distance between the wishbones and knuckle height ?
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: the distance between the wishbones and knuckle height ?
* that coupled with de Dion was supposed to make it understeery, which seems reasonable enough considering RWD with something like 600 BHP/ton, even though ZF cam and pawl LSD was used.