Super Aguri - new variable geometry suspension

G-Rock · Post 27 Jul 2006, 20:17

Has anyone heard of SA's new vario suspension? I saw it during practice at Montreal and then on television practice again at Indy. One tire engineer told me it would be used on the new car if effective and that their tire manufacturer was working with them to develope a special tire for them.
Didn't Renault run such a device two years ago to take advantage of the square shouldered Michelins?
This could be a breakthrough for them if it works. Their chassis needs a breakthrough as it doesn't look much different than the Arrows based chassis.
Increase da peace....

zac510 · Post 27 Jul 2006, 20:50

In what plane is it variable?

G-Rock · Post 28 Jul 2006, 02:36

It seemed to me (i have a photo but it's too dark to see any detail) that the upper rear A-arm had an extra pushrod which would then pivot the upright under load or something like that. Those guys are up to something though, i know it.

DaveKillens · Post 28 Jul 2006, 02:40

Most likely the camber changes depending on sideload.

Ciro Pabón · Post 28 Jul 2006, 03:52

Isn't this the function of multi-link suspension? I understand the A-arms are of different lengths to:

a- Minimize the camber variation when the wheel moves up and down and,

b- When the body rolls in a curve, the longer lower arm moves the bottom of the wheel out of the curve more than the shorter upper arm moves the top of the wheel towards the center, to maximize adherence.

I wonder, Dave, if this second function of multilink suspension clasifies as "camber change" or it is just a "rolling out" of the wheel to use the better friction angle the walls have. Anyway, the tire is rotated seen from the front...

The springs of an F-1 car have variable spring rates. I believe this is the function of the levers and cranks that connect them to the pushrods: to make them "harder" the more compressed they are.

So, my question is: what exactly is variable suspension? What does it vary that is not adjustable through the "normal" elements?

As usual, a drawing would be most helpful... Thanks in advance.

ginsu · Post 28 Jul 2006, 05:51

I think they would normally call a Short-Long Arm suspension design 'negative camber gain' type under jounce. While other designs like MacPhearson strut usually gain positive camber under jounce.

Variable suspension geometry would imply that the wishbones' attachment point is moveable in some way. I wonder if is passive or active (i.e. can the driver choose to turn it on/off)?

MrT · Post 28 Jul 2006, 09:14

It will be passive otherwise its against the regs as it would then be active suspension which is prohibited.

Multi link suspension does indeed lead to camber compensation, although with the geometrys used these day they can;t always achieve the optimum, as suspension geometry is secondary to the aero considerations. For instance, look at all the keel-less chassis, they all seem to run loads of static negative camber on the fronts - bad for braking.... in my view this is because there wishbones are almost parrellel resulint in ICs occuring along way away from the chassis and therefore resulting in poor camber compensation in roll, and therefore static camber must be used to get somewhere near the camber required in cornering (roll conditionc).