Idea :adjustable rebound and compression on sway bars

[myne]

Ok, I realise this is pretty out there, but the idea has been bugging me for a while, and I think it's a good idea but I cannot for the life of me figure out WHY it'd work better.

Basically, the sway bar in my mind transfers the coil spring's force from one side of the car to the other. As one side compresses, the force of the compressed side's spring attempts to compress the rebounding spring on the other side. The amount of force applied depends on the stiffness of the bar and the leverage.

What if... you could modify the leverage?

I figure if you could make the rebound lever shorter and the compression lever longer, you'd end up with more force being applied to the rebounding spring which might result in that spring being compressed more.

How would we do this?

Basically, I was thinking something along the lines of 2 sway bar links. Both would be in different positions along the length of the "lever".
The closer link would provide the upward push on the rebounding side, and the outer would provide the downward pull from the compressing side.

There are 2 ways I've thought of to do this.

1, slotted links that work one way and slide the other
2, hydralic links with 1 way valves

but I guess the bigger questions that are bugging me are :

1) why bother?
2) would it do anything interesting to the performance?
3) why do I have this insane feeling that it'll work?

[ViPeR_NiPPleX]

no point because the shock absorber is already doing this job?

[The Real Roadrunner]

i want whatever your on, life seems more fun in your world

cheers
linden

[myne]

rofl I literally just said that to a workmate

[horse]

...........

[oldcorollas]

I figure if you could make the rebound lever shorter and the compression lever longer, you'd end up with more force being applied to the rebounding spring which might result in that spring being compressed more.

and how would that help? surely you would just transfer more weight to the loaded wheel and make things worse? (ie, same as a stiffer bar)

[thechuckster]

i like the swaybar systems on the rear of the red-bull F1 cars and other race cars featured in race magazine.

similar to the pic below but the centre of the sway bar is connected to the chassis via a small adjustable coilover shock

IRL example:
http://www.schuerkamp.de/zope/hoover...7_irl_rear.jpg

[The Last Streetfighter]

ACE is a unique Discovery Series II option that measures vehicle speed and lateral "g" acceleration and automatically adjusts special two-piece roll-control modules during cornering. The roll-control modules replace conventional anti-sway bars.

Anti-sway bars are designed to limit body lean in curves by restricting the overall movement of suspension components. Making the anti-sway bars too thick increases the harshness of the ride over bumps and limits the ability of the axles to articulate-travel in opposite tilt relative to each other and the vehicle. On ACE-equipped vehicles, two accelerometers-one mounted in the vehicle's headliner and the other near the floor-detect cornering forces before the body begins to lean, making the system truly active, not reactive. These sensors instruct the ACE computer to apply hydraulic pressure to a set of actuators, one on each anti-sway bar. These actuators-basically hydraulic cylinders with multiple links-apply torque to the anti-sway bars, giving them added ability to counteract vehicle body lean. It all happens in a flash. ACE can build up sufficient hydraulic pressure to counteract 1.0 g of lateral acceleration in less than 130 milliseconds.


Taken from: http://media.ford.com/article_displa...rticle_id=5638

[myne]

and how would that help? surely you would just transfer more weight to the loaded wheel and make things worse? (ie, same as a stiffer bar)

I seem to think that it'd allow a softer bar to do the same job as a stiffer bar, but interfere less with the springs under normal bump conditions.

[oldcorollas]

but as you said... if you hit a bump, the greater leverage on the rebouding (drooping) spring, will pull it up more...
so it will unsettle the car more for normal bumps?
and for cornering with bumps? even worse?

if anything you want to decouple bump and roll totally..

[Lachie]

i like the swaybar systems on the rear of the red-bull F1 cars and other race cars featured in race magazine.

similar to the pic below but the centre of the sway bar is connected to the chassis via a small adjustable coilover shock

IRL example:
http://www.schuerkamp.de/zope/hoover...7_irl_rear.jpg

No, its not connected to the chassis by a small shock absorber. It does the same thing as a conventional sway bar, it just works a little differently. The principle of the sway bar works the same, its jsut the mechanism thats different.

Its sometimes called a 'T-bar' swaybar beacuse the mechanism looks like a T.

The T piece that you can see between the two bellcrank is allowed to pivot around the large bar at the bottom.

In bump, (two wheel bump) the T piece rotates around the bottom bar, so it effectively does nothing. In roll, the bellcranks rotate in opposite directions, so it tries to twist the vertical shaft of the T piece. This transfers the spring load from one spring to the other and volay, sway bar.

[thechuckster]

sorry, was a little unclear - the Red Bull F1 car, not the IRL car in the link - as featured in Race magazine, issue 4, pg 54, pic 2 - would love to put up a pic but Neil and Zac from PF wouldn't appreciate it without me asking.

[rms]

He means the third spring connected to T bar, not effective in roll, to cope with aero loads.

[myne]

wow that is a great concept - cheers for explaining it lachie

And Oldcorollas ; cheers for figuring out what was wrong with my idea - i basically thought of this and many other ideas while I try and get to sleep. It's more annoying when they wont go away because I cant figure out what's wrong with the idea.

[Lachie]

No worries.

I forgot tot mention, like old corollas said, decoupling roll and bump is the best way.

If you were thinking of going to the trouble of installing hydraulic cylinders, have a look here.

http://www.kinetic.au.com/techno.html

These guys have managed to do just that. The WA formula SAE team us a modified setup of one of these systems and it works a treat