alan-g-w
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Registered: 9th Nov 07
Location: Glasgow
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quote:
Originally posted by gazza808
Because the beam flexs, the arb just makes it stiffer.
Jack a Corsa up take the shocks and springs out, put one wheel back on so it touches the floor, stand on the other sides drum and watch how much it twists/flexs
Yup, they're not a solid part Steve. It's a 20mm or so rod going from hub to hub underneath, the top piece is just a formed bit of 5mm or so sheet metal and that's just welded on top and welded to the hubs on either end.
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John
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Registered: 30th Jun 03
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Is that the same set up as a fabia?
Only car I've had experience of one on but as said by others, transformed the handling. I've not got an explanation for you but definitely not placebo.
Lifted both. Ack wheels when jacking one side up which it didn't before so was vissably stiffer.
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alan-g-w
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Registered: 9th Nov 07
Location: Glasgow
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It makes the beam stiffer, reducing flex, as gazza said
[Edited on 19-02-2012 by alan-g-w]
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Nic Barnes
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Registered: 5th Apr 04
Location: nowhere near ginger people
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for handling improvements on a corsa, id say its almost essential to get one tbh.
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sand-eel
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Registered: 15th Mar 07
Location: carluke/braidwood--IRNBRULAND
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The technnical reason why RARBs work is it raises the "roll centre" height, that is an imaginary line where the pivot points etc cross each other.
FWD cars rear suspension is designed to have a low RCH so it understeers.
Bye.
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alan-g-w
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Registered: 9th Nov 07
Location: Glasgow
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Is that just a fancy pants way of saying it reduces flex Laurie
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sand-eel
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Registered: 15th Mar 07
Location: carluke/braidwood--IRNBRULAND
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Basicallyish...it also puts more "dynamic weight transfer" at the back too.
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AlexW
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Registered: 25th Oct 08
Location: Essex
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quote:
Originally posted by alan-g-w
quote:
Originally posted by gazza808
Because the beam flexs, the arb just makes it stiffer.
Jack a Corsa up take the shocks and springs out, put one wheel back on so it touches the floor, stand on the other sides drum and watch how much it twists/flexs
Yup, they're not a solid part Steve. It's a 20mm or so rod going from hub to hub underneath, the top piece is just a formed bit of 5mm or so sheet metal and that's just welded on top and welded to the hubs on either end.
The rod is the standard ARB, Low spec corsa's (Like my old 1.0) don't have that.
With no ARB and no shocks connected, how easy it is to twist is quite visual, and also quite a lot of movement.
I felt a huge improvement on the 12v, going from no RARB to the Cav one, really helped understeer.
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Ian
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Registered: 28th Aug 99
Location: Liverpool
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quote:
Originally posted by Steve
a solid rear beam like that isnt a torsion beam, it shouldnt twist if at all
It should and does.
Torsion beam means when the beam is exclusively sprung using torsion, ie. the trailing arms subject the torsion rods which run along the beam to a rotational moment.
A rear beam and springs as per the Corsa or Puma doesn't exclusively rely on torsion because the trailing arms are supported by springs, however there is still a torsional moment on the beam where there are differing loadings on each wheel, the extent of which dictates the amount of roll in the rear end, which is why it matters when you do things which affect it.
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Bakes
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Registered: 14th Jan 09
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This is the most interesting post I've read on here for a while. I can see where your comin from with the whole thing and I've also heard they make a HUGE difference. Atleast I now understand the science. 
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willay
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Organiser: South East, National Events
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Registered: 10th Nov 02
Location: Roydon, Essex
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make a massive difference, had one on my corsa b and got one on the astra.
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pow
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Registered: 11th Sep 06
Location: Hazlemere, Buckinghamshire
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I've always thought this but never wanted to say anything incase i look a dick 
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3CorsaMeal
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Registered: 11th Apr 02
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Put one on corrado, took it off after a couple of weeks.
The beams have to twist.
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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Puma one is pretty solid, not much flex in it, maybe why its more lively
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3CorsaMeal
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Registered: 11th Apr 02
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Corrado spec says:
"Trailing arms with track-correcting bearings, torsion beam axle, anti-roll bar"
This is it when i took it off
The RARB i bought
I put it on, then decided i didn't really need to drive round with a extra few kilos of metal bar bolted to the rear beam.
If VW didn't think it needed it, then why should i? , plus i thought it was naff and just a shaped bit of metal rod 
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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does an arb not just mean the car will lift a wheel easier?
less traction there bluds
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Mertin
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Registered: 12th Oct 05
Location: Scotland
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quote:
Originally posted by John
Is that the same set up as a fabia?
Only car I've had experience of one on but as said by others, transformed the handling. I've not got an explanation for you but definitely not placebo.
Lifted both. Ack wheels when jacking one side up which it didn't before so was vissably stiffer.
Fabia will be the same as the ibiza and the rarb bolts to the bottom of the shock, and then u bolts and bushes to hold it along the beam
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antnee
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Registered: 30th Dec 07
Location: Cov Drives: Clio 197
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No steve, less weight transfer, therefore more even weight across the rear end therefore more grip.
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antnee
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Registered: 30th Dec 07
Location: Cov Drives: Clio 197
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quote:
Originally posted by sand-eel
The technnical reason why RARBs work is it raises the "roll centre" height, that is an imaginary line where the pivot points etc cross each other.
FWD cars rear suspension is designed to have a low RCH so it understeers.
Bye.
I thought it was just increasing roll stiffness? I haven't done anything on RCH for beams, but I don't see how an ARB would effect the height
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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quote:
Originally posted by antnee
No steve, less weight transfer, therefore more even weight across the rear end therefore more grip.
but it does lift a wheel easier?
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LeeM
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Registered: 26th Sep 05
Location: Liverpool
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it will lift a wheel easier with an arb on and it will be easier to induce oversteer.
probably why people feel such a difference. im wondering though, handling characteristics will have changed but will the handling have actually improved
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John
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Registered: 30th Jun 03
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Fabia felt much flatter on corners, I never took it to the nurburgring so that isn't an elite confirmed review.
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Ben G
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Registered: 12th Jan 07
Location: Essex
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renault clio's lift wheels and they are known to be one of the best handling fwd cars around, can't be a bad thing.
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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do clios have rarbs on beam setups?
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John
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Registered: 30th Jun 03
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Imagine if you'd just bought a clio Steve.
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