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And why do you go round corners with the clutch depressed exactly. And no it doesn't but you sound not be doing it. Regards Peter.
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I read an article a while ago saying that most people didn't realise that ABS brakes don't work unless the clutch is depressed, because it can't vary the rotational speed of different wheels if the drive is connected.
I did wonder whether that was really true.
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>>the rotational speed of different wheels if the drive is connected.
Surely cars have differentials allowing the rotational speeds of different wheels to vary.
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True, but I think the argument was that the combined wheel speed was fixed to engine speed, whereas ABS might want to determine a different speed.
It makes a kind of sense to me, but I have never seen the de-clutch requirement stated anywhere else, so I do wonder.
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Yes, even if the ABS is clever enough to do one wheel at a time, when one wheel is locked, the other one's going to be doing twice the speed it usually does for that gear/engine revs.
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My automatic has ABS, so whilst I was sitting here thinking \'must remember to depress clutch, just in case Cliff is right\', suddenly in a flash of realisation, I don\'t have to as I haven\'t got one. On an auto then, does it do something clever to disengage the drive?
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just in case Cliff is right\',
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It's not my theory, I'm just quoting what I read!
But I would quite like to hear an expert explanation of how ABS works. What does happen if it wants to lock, or perhaps release, both driven wheels, yet they are connected to and therefore constrained by engine speed?
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ABS never "wants to lock" a wheel - all it can do it take the brake(s) OFF. (Talking about "classic" ABS by the way - I have no idea if very modern cars have some clever traction-related thing etc.)
Cheers,
Mark
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Sorry, Cliff! That didn't come out quite right...
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As was said ABS prevents any wheel from locking.system checks all wheels to prevent locking at the same time.if it didnt there would be no point in having it.Dont know whether they are now combined with traction control.possible.ABS has or didnt have any control of drive.so depressing clutch pedal has no effect on ABS.diff controls wheel speed on bends/turns ie it allows wheels to turn at different speeds without affecting the engine speed/revs.
Hope that helps
Was mech1
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.diff controlswheel speed on bends/turns ie it allows wheels to turn at different speeds without affecting the engine speed/revs.
Different speeds, yes, but for a given engine speed they are necessarily constrained by the differential. Any reduction in speed of one wheel has to be compensated by an exact increase in speed of the other. I was wondering what happened if the preferred speeds for each wheel, as determined by the ABS, were not permitted by the differential. That I think was the basis of the declutching theory.
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" And why do you go round corners with the clutch depressed exactly."
Its a great way to mask knackered front CV joint/s.
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Admission time...
As a non two pedal pusher (ie I push the clutch only when it needs it) I can utterly confirm my ABS works fine if I don't push the clutch.
As Land Rover Defenders are not know to being at the cutting edge of technology I'm sure all others are the same.
Indeed it could be argued that operating the clutch makes you more likely to lock a wheel, not less (friction in diff and having a retarding force applied by the engine).
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On the other hand, a big heavy engine will not slow down instantly, and your brakes will have to reduce its speed, and not the speed of your car.
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OOh, is that true, David Horn? I'm not convinced that a car's flywheel is big enough for that to be true, but I'm waiting to be convinced.,
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>>And why do you go round corners with the clutch depressed exactly. And no it doesn't but you sound not be doing it.
I seem to remember from a fairwhile back a skid control technique that involved depressing the clutch.The name Robbie Slotmaker?? a Dutchman IIRC
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I've no idea whether it's true or not, but probably in the first few seconds. Then letting the clutch out again would give an engine braking effect.
To be honest, it was a wild guess... thought I wrote that underneath. D'oh!
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