rear anti roll bars, thicker the better?

[Jaff]

Its not about a clio, but i'm looking to upgrade the Rear ARB on my C30, now i know a thicker bar will improve handling and reduce body roll, but there are 2 options for me, a 22mm fixed one or a 24mm adjustable both from whiteline. The parts arent designed for my car but they are for a focus and from looking at my car every single suspension componant has FoMoCo stamped on them and ut all looks identicle to a mk2 focus.

so it'll fit, but i cant deside whats would be best for me, i'll never see a track. does any one have any experience with these? is it worth spending the extra for the extra thick one or is it over kill for road use. on the mazda3 mps, which has the same suspension (well slightly different droplinks but they are cross compatable), you can get Rear arbs/swaybars up to 32mm, but that apprenlty makes the rear end completly rigid.

Ive looked about on the C30 forums and they all agreed an uprated rear ARB is a must have, but none seam to have tried this kit or any brand other than iPD or Evolve/elevate, and those kits like twice to 3 times the price of either whiteline kit.

any advise?

 

[rory182]

What diameter is the original? If you're not tracking it I would't bother with adjustable

 

[Jaff]

I think stock its 18 or 19 mm.

 

[Phil @ P5]

A lot does depend on spring rates, which of course is based on a number of factors (eg corner weights and motion ratios) so you can't compare x rate with y rate and say one is stiffer than the other.

From a tuning point of view you DO NOT want to stop roll. The dampers are there to control the transfer of weight and if you limit the amount of roll you limit the amount of damper movement; the dampers can only produce a force if they are moving!

So look at the ARBs as a way of distributing the roll moment. For an OE set-up there are a lot of compromises that have to be taken into consideration (think of the result when you put 4 blokes in the car and then load the boot with beer; that sight might be familiar in the next few weeks!) so there's normally some improvements to be made. Using a stiffer rear ARB with stock springs should result in improving the balance of grip between the front and rear.

Picking a size is a little harder, it requires some measuring and calculations. Just don't be tempted into thinking the stiffer the better. Suspension is designed to move, making it rigid is a bad idea, and can be downright dangerous.

HTH
Phil

 

[Jaff]

I'm getting prolines which will stiffen things in its self so going for the extra thick bar might be too stiff. So I think the 22 mm will be the best comprimise.