Have bought a Whiteline RARB can anyone tell me what setting this is best set at ie what hole should the bolt be put through, I don't want some psycho rear end behaviour, I am not using the car for racing simply upgraded performance and grip.

If you have good rear tyres and the rest of the car is fairly decent handling i'd put it on the middle or hardest. obviously more likely to oversteer but i've never had it happen other than with ****ty tyres.

 

maybe if you have stock/ soft suspension rather than coilovers you want more or less stiffness on the RARB?? not sure what the answer would be

 

 

Wet conditions may be a bit different but you would likely be going slower in the wet or slippery conditions anyway!

 

 

 

 

An antiroll bar effectively reduces grip on the end it's fitted, the intention being to change the balance of the car (for the better). Rear ARB will loosen the back end. I would start out on softest setting to avoid getting suddenly surprised by massive oversteer in the wet. Explore the handling and see if the rear end is to your liking. After an adequate trial 'shorten' the arms and try it again. Repeat as required.

This way you get used to its effect in easy/non shocking stages. Down to your car and driving style where you end up setting it but preferably not in the hedge.

Edited 22 September, 20187 yr by LB123

I'd personally stick it on the stiffest setting. I had a Jabba rarb which is much thicker than the whiteline. No adjustment on it. 

 

Never had any lift of over steer moments. Helped turn in and on you could get the rear to start moving around a bit but was never anything to worry about.

@Boatman1 - I agree with LB123 that the only effect of a RARB is to reduce rear end grip!

8 hours ago, KenONeill said:

@Boatman1 - I agree with LB123 that the only effect of a RARB is to reduce rear end grip!

 

 

less roll?

 

I know that decreases grip on outer wheel, not sure how it helps but it does

 

 

Edited 24 September, 20187 yr by corndog

It reduces understeer, thereby increasing front end grip, this improves the balance of grip between front and rear because the rear has far more grip than the front and can trade some for better front grip and overall handling.

Thank you all for responding, will start off in middle position and test in wet conditions, see how it handles, have B12 suspension fitted.

@Boatman1 @corndog @sepulchrave - A RARB works by effectively increasing transverse spring stiffness using a torsion bar to couple the rear wheels. This means that when the car rolls it lifts the inside rear wheel, and we've surely all seen a picture of a mk1 Golf with that wheel several inches up in the air?

1 hour ago, KenONeill said:

@Boatman1 @corndog @sepulchrave - A RARB works by effectively increasing transverse spring stiffness using a torsion bar to couple the rear wheels. This means that when the car rolls it lifts the inside rear wheel, and we've surely all seen a picture of a mk1 Golf with that wheel several inches up in the air?

 

Yes, that's how it works, but that doesn't describe what it does.

 

You cannot consider the rear suspension in isolation from the front, it's a complete system, the RARB has a dramatic effect on the overall handling of the car and increases outright grip in the way that I described.

 

I also have the complete B12 setup and a Whiteline RARB and mine is in the middle setting for stiffness because I drive on shocking road surfaces and a RARB reduces suspension compliance and therefore grip on bumpy roads.

I also have my Whiteline arb on the middle setting with standard springs but Bilstein B8 mono shocks all round. Great improvement with less body roll and you really have to push it hard, crazy hard, to get any oversteer. I like oversteer though. It does help, me being a skid car trainer as part of my job.

@sepulchrave - No it doesn't. Increasing roll stiffness at one end, in isolation, just reduces grip at that end. A brain burp is refusing to release the relevant names, but unless you have a higher degree in Automotive Engineering I'll take the sources I'm quoting over your statement.

1 hour ago, KenONeill said:

@sepulchrave - No it doesn't. Increasing roll stiffness at one end, in isolation, just reduces grip at that end. A brain burp is refusing to release the relevant names, but unless you have a higher degree in Automotive Engineering I'll take the sources I'm quoting over your statement.

 

I do indeed have a higher degree and worked in motorsport engineering for some years (you're expected to work for love, not money) so I understand the principle, proper suspension bods will tell you a RARB is a kludge and they're right but when you can only p!55 with the d!ck you've got then a RARB makes sense, the maths is not complex.

 

Also, I already have one so I actually know it works.

 

The Fabia already has a torsion beam rear axle so adding a RARB simply stiffens it to help reduce body roll, this in turn reduces the positive camber on the outside front and rear wheels and increases grip and improves handling feel dramatically.

 

What do you think would happen if you sliced out the rear torsion beam altogether to make the radius arms independent? Would the car handle better or worse and would grip improve?

Edited 25 September, 20187 yr by sepulchrave

13 minutes ago, sepulchrave said:

What do you think would happen if you sliced out the rear torsion beam altogether to make the radius arms independent? Would the car handle better or worse and would grip improve?

You're just being silly here. You know perfectly well that the trailing arms would fall off!

 

If you converted to a true independent trailing arm suspension, then yes you would need to increase the rear spring rates to restore rear roll stiffness.

17 minutes ago, KenONeill said:

You're just being silly here. You know perfectly well that the trailing arms would fall off!

 

If you converted to a true independent trailing arm suspension, then yes you would need to increase the rear spring rates to restore rear roll stiffness.

 

It's a thought experiment Ken, I'm not suggesting anyone try it.

 

So if we're saying that removing the torsion beam is a bad idea, should we stiffen or soften it, or is it just about right as it is?