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(16-01-2014, 08:43 PM)Poodle Wrote: Continental whats? If they're eco tyres then they certainly won't help, but if you've got something similar on the front then start looking elsewhere for the root of the issue. I'd suspect something knackered on the rear beam is the culprit.
Sam, get someone capable to look at your car sharpish, if you've noticed actually an issue by yourself then it's probably about to explode in a ball of flames.
yes thats what I am worried about. The fact that if Ive noticed a problem it must be serious haha
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17-01-2014, 12:14 AM
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(16-01-2014, 02:29 PM)deggerz Wrote: I have a hdi dturbo and if I give that some stick on a long tight bend I can feel the back end stepping out If you mean give it some stick as in give it some throttle then you have suspension/tyre issues as it should understeer under these circumstances.
(16-01-2014, 06:12 PM)boggs Wrote: I just get lift off oversteer and a lot of it but then again my hdi is really low
(16-01-2014, 06:13 PM)deggerz Wrote: I've heard lowering does exaggerate it
No your both wrong, lowering helps cure it as the lift off oversteer is caused by the weight transfer back to front causing the rear suspension to lift and the trailing arms to turn and also turn in (because of the passive rear wheel steering) and this causes the back end to step out.
Less suspension travel and stiffer dampers mean that when you lift off the suspension doesn't travel as far so the rear arms don't steer so much so it wont oversteer so much
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Yeah Sam, i pretty surprised you're not dead already tbh.
Lol wolverine, take all that crap out the boot and you won't be on the bumpstops, which should help massively.
Dude that explanation totally made me go crossed eyed, and i'm not entirely convinced you're right... Passive rear wheel steering is just that - passive rear steering - ie not oversteer... Lowering doesn't stop or reduce weight transfer (i don't think..? Ripp?), it just stops the suspension reacting as much by reducing the travel. Really low cars suffer badly because there's not enough suspension travel to keep the contact patch up, so it takes less to unsettle the car. Higher spring rates on the rear, or softer on the front, also make it worse, as do similar changes to the arb. Another factor is that most people buy poorly specced springs and dampers on the cheap to do the lowering, which again reduces the effectiveness of the suspension as a whole.
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17-01-2014, 06:12 PM
(This post was last modified: 17-01-2014, 06:13 PM by Toms306.)
I've managed to make several 306s oversteer...lifting off or braking mid corner has that effect. As do shit 'snappy' tyres like T1R's.
Also if the tracking is as far out as it was in Rowells estate, that can also cause pretty bad oversteer, followed by massive over-correction and the need for fresh underwear.
Over-inflated rear tyre's also cause problems if theres no weight over them (empty fuel tank for example), has the same effect as stiff rear shocks, which are crap on rough roads, massively reduces tyre contact patch.
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17-01-2014, 06:24 PM
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When I mean giving it some stick I mean sorta lifting off mid corner because I realise I'm going way to fast, i've never actually had it step out, you can just feel it sorta go light if that makes sense
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70k means nothing at all, I have had beams with less than 50k on them completely dead even thou they looked Ok camber wise, Just the rust holding them together
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Ooo interesting article, cheers! Seems i've got it pretty confused too lol, oops! Makes a lot of sense, hadn't thought about the way the complete geometry change would affect it. I'm only down about 50mm and my wishbones are far too close to horizontal at rest for my liking, and it shows in the way the thing handles - you can feel the outside front wheel tucking under hard cornering.
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17-01-2014, 10:48 PM
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The beams are fine, Any bush or suspension part on a car wears out, The issue with the Beam is water gets in around the seal which I tend to say needs replacing every 5 years with new grease, Then its a downward slope, Having the car stood for any time doesn;t help either as thats when the rust can lock them up solid
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19-01-2014, 10:04 AM
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19-01-2014, 11:01 AM
(This post was last modified: 19-01-2014, 11:02 AM by Toms306.)
Mk4 Golf rear beam is completely different though, it's not a torsion bar system with trailing arms and bearings and stuff, its a solid lump so the only part that can wear out are the 2 rubber bushes that the entire beam pivots on. So easy to lower/fix compared to the PSA torsion bar equivalent though!
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19-01-2014, 02:04 PM
(This post was last modified: 19-01-2014, 02:09 PM by Rippthrough.)
(19-01-2014, 10:04 AM)Wolverine1091 Wrote: Fair enough, so much easier with independent suspension though.
mk4 golfs/a3's have a rear beam and they outlive the car.
The Golf is a beam, that's why. Not independent
The 306 is independent, so I'm not sure why you think it's easier with independent...
And that Golf is going to bend the upright the first time any serious force goes through it. Not to mention fail the MOT.
(17-01-2014, 05:59 PM)Poodle Wrote: =
Dude that explanation totally made me go crossed eyed, and i'm not entirely convinced you're right... Passive rear wheel steering is just that - passive rear steering - ie not oversteer... Lowering doesn't stop or reduce weight transfer (i don't think..? Ripp?), it just stops the suspension reacting as much by reducing the travel. Really low cars suffer badly because there's not enough suspension travel to keep the contact patch up, so it takes less to unsettle the car. Higher spring rates on the rear, or softer on the front, also make it worse, as do similar changes to the arb. Another factor is that most people buy poorly specced springs and dampers on the cheap to do the lowering, which again reduces the effectiveness of the suspension as a whole.
Lowering does reduce the weight transfer as the CoG drops.
However, the passive rear steering is done on the rubber beam bushes, so how much rear steering you get is pretty much directly related to how fooked the rear bushes are and how hard you're cornering.
There's the other issue with lowering the rear though in that most people don't stiffen the rear springs and dampers to compensate for the reduced travel, hit the bumpstops mid-corner and the suspension acts like a pogo stick from then on because the damper cannot control the sudden jump in spring rate = snap oversteer.
You've only got to watch a rally crash compilation on youtube to see how many 205's/106's and 306's do this when they've got the ride height wrong and it sends them into a tree.
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