Anti Roll Bars and Uprated Torion bars!

[Timlowthian]

Couple bits of info id like to know!

First off what does the ARB's actually do? And what would be the benafit in uprating these?

Same with torsion bars really whats the benafit in changing these?

Then while looking at them on kam they do all different sizes for saxo whats they difference between all these?

Sorry for all the questions just wondered about it all really! No point buying things i dont understand lol

[davidharvey]

Think there are a few of us "suspension newbies" about
The more I look through past posts the more confusing it gets

Guide anyone?

[VTR-120BHP]

well from how i understand it the arb ( anti roll bar ) prevents the car from rolling so a bigger arb would mean less roll... in theory.

not to sure on torsion bars thou so someone explain :D

[Ryan]

fitting bigger torsion bars is just like fitting harder springs to the front of a car.

[titchster]

Front ARB stops the vehicle from rolling (as per its name) in corners, the smaller the ARB, the more the car will lean, and to an extent it can 'tripod', or 'cock its leg up', ie: lift the rear wheel, to a certain extent, I always see this as a good thing, as more weight is being put over the turning wheels, so less chance of understeer, yet, at the same time, more weight is being thrown off the back end, so more chance of oversteer.
Stiffer ARB on the back means the rear is stiffer, so again, more likely to tripod.


Torsion bars act as springs, so bigger bars, act like stiffer springs.

Think that's about right, if not, someone will correct me.

[AlexB]

about spot on titch

[AlexR]

Anti roll bars work by transferring weight to the opposite side, like stabilisers on a bike.

This isn't great for handling.

Anti roll bars are used because they allow you to run softer springs but get the same amount of body roll and stability, this obviously gives better ride quality. Ideally for optimum track performance you want smaller anti roll bars and harder springs, for optimum road performance you may want large/larger ones, and softer springs.

Torsion bars are just springs.

The analogy above isn't quite correct. If the body roll at the front is excessive the contact patches of the tyres, and the suspension geometry will be far from optimum, this will reduce grip at this end. The tip to front/rear stiffness is balancing the spring rates and anti roll bar rates to give a combination of ride quality, grip and predictability.

For instance fitting a bigger front anti roll bar on its own will probably increase the likeliness to understeer, but fitting a bigger front and a bigger rear one will most likely retail the balance but improve grip & handling.

[titchster]

So, I was almost right, but not quite right? Im happy with that, i'll admit its still vague to me, but it shows to me that im learning.