Isn't that a straight beam from one hub to the other though?

Not a torsional design like the fabia where it twists the beam under cornering? Basically, what the rear ARB is doing is stiffening up the beam so it cant twist as much under load.

Haven't you just answered your own question? The less twist and flex there is in the beam, the more it behaves like a live axle (without a driveshaft in it :P ), surely?

Don't get me wrong: I'm not saying they do nothing; just that the effect they have is to reduce the limit of grip on the rear at the limit rather than improving the grip on the front. So, yeah, it makes it easier to induce a drift, and it'll make the rear of the car roll less by merit of the fact that more force is transferred along the beam to the unweighted spring, but it won't turn the car into a drifting machine, and it won't allow you to take corners any more tightly unless you have the skills to maintain control in a drift (which I'm not about to claim I have!) The fact that the car is rolling less might make it feel like you are able to take corners more quickly, but whether that's more than a sensation, I can't say... :ne_nau:

Then again, the Fabia vRS is renowned for feeling faster than it is due to the 'PD punch' so maybe I'm focussing too much on the trees and need to concentrate more on the wood... :confused:

To the OP...

The RARB definitely does quite a lot of something. I have the Jabba one and it really helps pull things together. I don't tend to drive like a tit or try to attain maximum "G" cornering but even shy of the limits it's worth it.

My advice is to buy a RARB rather than not buy one. Without one, the Fabia's rear end is an unpredictable, lurchy mess.

J.

So you know for a fact that the problem is a lack of rear roll stiffness, and not too much front roll stiffness, or front spring rates being too low, then?

I'm pretty sure Apogee is right about the practical effects of a RARB being reducing rear grip (which reduces understeer, but not in a good way).

We need stig to take a fabia out around the top-gear test track with and without the rear ARB

Kev

I have the whiteline on stiffest setting.

Definitely corners a lot better with it on, but makes the rear end skittish in the wet.

Might move it back a notch now with the coilovers on.

This is Nick Porter following my car into Padock Hill at Brands.

Well that was a "small-world moment" - I used to work with Nick, and still do on the VERY odd occasion!

Sorry.....back on topic....

pL

Oooh blimey

I have never lost the rear end , but then I do drive like a girl :lol:

I just love the way my car just drives round the bends , its great , and it feels stable too

I have to agree with Jabba though ( should I say that.....ooh yes) get the stig on it

Sarah

:popcorn:

So, have you bought one yet?!

Isn't that a straight beam from one hub to the other though?

Not a torsional design like the fabia where it twists the beam under cornering? Basically, what the rear ARB is doing is stiffening up the beam so it cant twist as much under load.

are you talking about the Renault ?

if so, a lot of Renaults have a torsion bar rear axle

I think in this case, he's talking about the Fabia...

If provoced then it will give a little liftoff oversteer - its quite fun tempting the rear end out on roundabouts!

OT, but my SEAT strut brace requires me to hold it with one hand, leaning back against it with all my weight, while inserting the bolts hand-tight with the other.

On a back-of-fag-packet basis, I reckon that's got to be a couple of hundred Newtons (I'm a hefty bloke!) pulling the turrets together. The most cornering force I've ever experienced was 0.7g (hardly F1 levels!!!), but again on a back-of-fag-packet basis, that works out as... a couple of hundred Newtons lateral force, which presumably is biased towards the outside wheels.

You lost me with this one. Yes if you weigh 65 KG (like me) then that equates to 637 Newtons. 1KG = 9.81 Newtons.

But 1G is actually a measure of acceleration not force .. ...........

However 1 KG force equals 9.81 Newtons.

So....... 0.7G equals 0.7 Newtons which equals 0.071 KG force Not a lot is it.

But the load put on the strut brace will not be the G force measurement, but the force induced by the transfer of weight from one turret to the other due to the body twisting under load multiplied by the extra force due to the G force. This WILL be quite high I expect. Does this make sense :confused:

I think this is what you meant.

Miles off from what I meant, I'm afraid: 100kg × 9.81 × 0.2 (for 18 degree lean) = approx. 200N. 1400kg × 0.7 × 9.81 × 0.25 (for 4 wheels) × 0.1 (factor to take account of different radius of path of inner and outer wheels of 2m wide car around 20m radius bend) = approx. 200N. Reasonable enough Fermi calculation, I thought...

So, anyway. Two choices:

Fabia VRS ARB

and

Awesome > Whiteline Rear ARB Fab/IB4/Polo 9N+9N2+GTI

Which one you picking?

Steve

Miles off from what I meant, I'm afraid: 100kg × 9.81 × 0.2 (for 18 degree lean) = approx. 200N. 1400kg × 0.7 × 9.81 × 0.25 (for 4 wheels) × 0.1 (factor to take account of different radius of path of inner and outer wheels of 2m wide car around 20m radius bend) = approx. 200N. Reasonable enough Fermi calculation, I thought...

Your 18 degrees is miles off, if it's a measure of the roll angle the car is actually assuming. I'd be surprised if it's more than 6 degrees on standard suspension.

Your 18 degrees is miles off, if it's a measure of the roll angle the car is actually assuming. I'd be surprised if it's more than 6 degrees on standard suspension.

I'm not talking about the car leaning 18 degrees - it's an estimate of how far back I have to lean to apply enough force to the brace to get the bolt holes to line up! :P

OK, so my ankles aren't plumb with the turret, and I only chose 18 degrees because it's one-fifth of a right angle thus making the maths easy, but I don't think there's anything too controversial there really...

Steve:

If any the whiteline, I just don't know now though.. I love the idea of a less rolly polly Fabia, but the technical loss off grip at the rear freaks me out a little.

The understeer I get at the minute when I find my self out of my comfort zone is manageable and predictable.. throwing a rear end that'll also slide into the mix maybe too much..... at the minute.

So, Next question.. anyone recommend one of those driving school, handeling lesson type things?

Book a taster session at a motorsport vision trackday (something like £20) and i'll take you round in my fabia with rear ARB on

Either that, or there's some nice roundabouts near Jabba

Kev

As ever, Don Palmer's "Creative Car Control" gets the big ol' Recommend off me (you'd think the guy was paying me to advertise!) I'd link my review for you, but I'm browsing on my phone - should be easy to find, though! It's pricey, however - you could have your pick of handling mods AND have change to spare...

Perhaps a skid pan day then, maybe?

Anyone been on a skid pan course? Do they run day trip experience thingys for them?

Steve:

If any the whiteline, I just don't know now though.. I love the idea of a less rolly polly Fabia, but the technical loss off grip at the rear freaks me out a little.

The understeer I get at the minute when I find my self out of my comfort zone is manageable and predictable.. throwing a rear end that'll also slide into the mix maybe too much..... at the minute.

You are honestly worrying about this too much. The scaremongers have done their job well

Please re-read the directly relevant parts of this thread. As many have said, you will not get a 'a rear end that'll also slide' UNLESS you deliberately provoke it. Many, many miles of 'progressing' and I never had a situation like that.

I think the only way forward for you is to either go out as a passenger in a Fabia so-equipped, or try someone else's - on a track/large area of private land etc.

I take your point about further driver training, and that can only be a good thing - but you will not be fitting a piece of overly dangerous equipment to your Fabia by fitting a rear anti-roll bar.

Steve

Couldnt have put it any better Wardy..

Kev

Whiteline it is then

Thanks Everybody for all the comments! I feel this thread has shown two valid sides of the argument for and against a retrofitted RARB. It's also taught me allot about exactly what it does, how it does it and why it does it..

Rob

You are honestly worrying about this too much. The scaremongers have done their job well

Please re-read the directly relevant parts of this thread. As many have said, you will not get a 'a rear end that'll also slide' UNLESS you deliberately provoke it. Many, many miles of 'progressing' and I never had a situation like that.

Steve

Scaremongering was never my intention; I was just trying to explain how an increase in rear roll stiffness works to reduce understeer.

That said "deliberately provoking the rear end" is a lot like "having to perform a panic stop in mid-corner".

I didn't have anyone specific in mind with that comment and certainly not within the confines of this thread anyway. The OP came to this thread with a pre-conceived idea about how the car would behave with a rear anti-roll bar fitted.

Steve

personally i find the body rolls slows me down enough so that i cant get near the limit of grip anyway, im leanin so far to the side on any kind of high speed corner i have to slow down just to feel like its not going to roll over

though i have come from a Clio Williams setup, which can out handle a LOT of other cars lol