scootz
|
| posted on 29/5/12 at 02:44 PM |
|
|
Anti-Roll Bars...
These have always puzzled me!
I understand what they do and how they do it, but could body roll not be controlled by just using stiffer springs on the dampers???
Can someone in the 'know' explain in numpty-terms why they are used in conjunction with a set of coil-over dampers?
It's Evolution Baby!
|
|
|
|
|
mikeb
|
| posted on 29/5/12 at 02:50 PM |
|
|
You don't in theory need them for a track car as you can control body roll just with springs
However they make adjusting the load transfer front to rear a lot easier and cheaper than changing springs. i.e dialing understeer/oversteer in and
out
For road cars they were a simple way of allowing softer springs for ride comfort and not letting the car roll too much.
What an engineer would really like is to completely decouple roll bounce and pitch and control them all seperately.
Unforunately an antiroll bar doesn't just work in roll it, so if you put a fat one on ride comfort will be really bad when the wheel are going
in different directions
[Edited on 29/5/12 by mikeb]
|
|
|
scootz
|
| posted on 29/5/12 at 02:52 PM |
|
|
Cheers Mike... that's pretty much the conclusion I'd drawn up in my head.
But I still see plenty of pics of very focused looking single-seater race cars with ARB set-ups.
It's Evolution Baby!
|
|
|
loggyboy
|
| posted on 29/5/12 at 02:58 PM |
|
|
Stiffer springs would do a similar job, but stiffer suspension would have other reprecusions, so bhy using anti roll bars it gives the flexiblity to
have a softer set up yet still control body roll. There is also a compromise with grip levels as its common for an anti roll bar to lift the inside
wheel causing less traction! Ive always felt they are better on track than on road, as it tends to be roads that have more uneven surfaces leading to
more likely loss of traction than on a nice smooth level track surface.
Mistral Motorsport
|
|
|
Bluemoon
|
| posted on 29/5/12 at 03:00 PM |
|
|
You could also look at mono-shock setups... No ARB at all..
i.e. http://www.scarbsf1.com/Monoshock.html
You would only need 2 shocks on you trike.. With control of roll. No idea if it would work well on the road (probably not!)..
[Edited on 29/5/12 by Bluemoon]
|
|
|
britishtrident
|
| posted on 29/5/12 at 03:13 PM |
|
|
One of the main reason why RWD cars nearly always have front anti-roll bars is that it allows the car ride bumps with less pitching ie the bucking
bronco effect.
If a front anti-roll bar is used then the front spring frequency can be reduced (by making the front springs softer) this means the front and rear
of the car will level out and land at the same time as it passes over a bump. The relationship between the front and rear suspension frequencies
is worked out by a formula based on the design speed of the car and the wheel base.
On fwd cars you will often find a rear anti-roll bar because they car so high a % of the mass at the front that getting the car handling balanced
without one would require making the rear springs so hard the ride would be foobared.
[Edited on 29/5/12 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
|
|
|
scootz
|
| posted on 29/5/12 at 05:23 PM |
|
|
quote:
Originally posted by Bluemoon
You could also look at mono-shock setups... No ARB at all..
i.e. http://www.scarbsf1.com/Monoshock.html
You would only need 2 shocks on you trike.. With control of roll. No idea if it would work well on the road (probably not!)..
Thanks for the link.
There appears to be an image on the webpage, but it won't display for me. Can anyone else see it? If so, could you please post it to this
thread?
Ta muchly!
It's Evolution Baby!
|
|
|
scootz
|
| posted on 29/5/12 at 05:25 PM |
|
|
I just can't get my head around why you would want to have an independent suspension... but then directly link the two opposing wheels with an
ARB.
It's Evolution Baby!
|
|
|
britishtrident
|
| posted on 29/5/12 at 05:46 PM |
|
|
Independent suspension really isn't that important a de Dion axle is every bit as good as a fully independent rear end but de Dion is very
awkward to fit in..
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
|
|
|
scootz
|
| posted on 29/5/12 at 06:19 PM |
|
|
I'm only really thinking about the front-end BT.
It's Evolution Baby!
|
|
|
phelpsa
|
| posted on 29/5/12 at 06:22 PM |
|
|
An ARB is twice as stiff in roll as it is in single wheel bump.
No suspension is independent in reality. There's a great big torsion bar, usually called a chassis, connecting all the wheels together.
|
|
|
craig1410
|
| posted on 29/5/12 at 08:46 PM |
|
|
Here's a good comprehensive article on the subject:
http://iracing.wikidot.com/components:anti-roll-bar-sway-bar
My simplistic explanation would be to say that and ARB allows control and adjustment of body roll without requiring excessive stiffness in the
springs. You want the springs and dampers to be set up to handle bumps as best they can, taking account of unsprung mass and tyre characteristics. The
ARB is a separate mechanism which can be used to control body roll which is important to ensure the tyre contact patch is consistent without having
massive amounts of negative camber. Negative camber can counteract some body roll but it should be borne in mind that lots of negative camber will
compromise traction and braking when in a straight line and can overheat the inside shoulder of the tyre.
|
|
|
