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ABS; SCARY STUFF

98 posts & 38 voices | Started 3 years ago by neverfastenuff | Latest reply from Drac

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Capt Cook - Member

I think my Audi had something called ESP. If you went into a corner and it skidded it would break the wheels individually (the ones required) to bring the car under control and get you round the corner. Ferrari & Lambo's have adjustable intevention for how much the car will keep you on the road.

Linking this back to original post, the sensors on the wheels when driving on ice can act straighten the car whilst breaking so traction control is helping to keep the car straight whilst it is decelerating.

Posted 3 years ago #
johnhoo - Member

yeah man, tripping on the euphoria of getting home from work in one piece thanks to my ABS, EBC, DSC, ESP or whatever it was that stopped me fishtailing like the car in front of me...

tune in, turn on, drop out, man

Posted 3 years ago #
Rich - Member

Capt Cook - Member

I think my Audi had something called ESP. If you went into a corner and it skidded it would break the wheels individually (the ones required) to bring the car under control and get you round the corner. Ferrari & Lambo's have adjustable intevention for how much the car will keep you on the road.

Yeah that's what my Verso has, think its more to do with under and over steer though.

Posted 3 years ago #
neverfastenuff - Member

But my Honda has ABS and EBD , but it still scared me at 10mph, so cars can be clever, but when those gizmos come on unexpectedly it is possible for the driver to overreact.
Tiff Needall drove a Lambo with all the gizmos turned off on a snow circuit and controlled it beautifully, he then turned all the safety gizmos on and the car would not even accelerate - that demonstrated perfectly the safety devices that help us all drive.

Posted 3 years ago #
jfeb - Member

If the abs sensor is broken the ABS light comes on and stays on.

Smee - No one mentioned the abs sensor. We were talking about the abs ring, which may or may not have caused the OP's brake pedal judder.

Christ - do you people know nothing about driving.....

LOL. Just read what is being posted better.

Posted 3 years ago #
2unfit2ride - Member

that's what I said

The OP was talking about ABS - anti lock braking. Smee & friends seem to have confused that with traction/stability control

At least read my post, how would a car know if the wheels were locked?

Ok, I'll spell it out for you, if all four wheels are locked then the speedo shows zero m/kph, if the speedo shows zero then the car thinks its stationary, how can the car then activate the ABS?

Go on, I reckon you can work out the rest for yourself

Posted 3 years ago #
Smee - Blocked

jfeb - thank you. you have just saved me replacing the cv joint on my passat.... Cheers,

Posted 3 years ago #
WTF - Member

ABS is great in the wet or dry even and utterly useless IMO in the snow.
Use the handbrake a bit as well this lets the tyres dig in a bit helping the car to stop.
Only for the experienced though.

Posted 3 years ago #
Drac - Moderator

ABS works fine in the snow simulates what we were taught do on our advanced driving many moons ago. One thing we told never to do was grab the handbrake.

Posted 3 years ago #
CHB - Member

I am surprised by the general lack of ignorance about this subject shown on this site.
Basically ABS is a system as described that has sensors on the wheels to detects locked wheels. The ABS is linked to a pump that pulses the brakes to prevent full lockup, thereby maintaining steering control.

Since its introduction, various manufacturers have linked other systems to ABS to make cars safer. My Audi A2 for example has accelerometers and steering angle sensors as well as ABS wheel sensors. The car uses the ABS system to prevent wheel spin, ie ABS system is used to give traction control. It will also use the ABS system to prevent sideways drift and skidding. Technically this isn't ABS, but the system is so integrated on modern cars that the ABS wheel sensors do more that provide straight forward ABS.

Bloody surprised you can drive for more than a couple of years and not use ABS. Also surprised how many on here clearly do not RTFM.

Posted 3 years ago #
druidh - Member

CHB - Member

Bloody surprised you can drive for more than a couple of years and not use ABS. Also surprised how many on here clearly do not RTFM.

Why the surprise? If you're driving in line with the road conditions, you should never need it to come on.
Having said that, when my wife was learning to drive, I intentionally sought out opportunities for her to try it - so that she wouldn't get the shock that the OP did.

Posted 3 years ago #
hora - Member

IMO ABS kicks in waay too early. First time it happened approaching a wet roundabout- NOT hooning etc or misplanning approach I thought 'why so early'? I didnt stab or suddenly press firmly etc.

Posted 3 years ago #
owenfackrell - Member

No abs system will work if all your wheels are locked but if one of them is still turning (such as hit a bit of ice on one side of the car) then the system will cut in and pulse the brakes.
It works by having sensors on all the wheels that look at the peaks and troughs in the abs ring and monitors the speed in relation to each other it has nothing to do with the speedo which gets its information from the final drive side of the gear box.
Different cars abs can be very different. I had a peugot where the pedal would sink when the abs cuts in but on my renault the pedal gets firmer.

Posted 3 years ago #
Djnova - Member

Eps/abs is scary on a Citroen C4, when you brake hard the pedal hits the floor and the car is meant to do the rest only problem is the initial reaction to pump the pedal when it hits the floor! It does helpully put the hazards on for you though.

Posted 3 years ago #
CHB - Member

To answer both Druidh and Hora, I don't always drive in strict accordance with the road conditions, and use adverse road conditions to test how my car reacts when brakeing heavily or trying to lock the wheels. If you don't test how your car behaves in these situations then the first time you have to manage a skid or really need the ABS then it will come as a shock. I just assumed that any owner of a new car will try out things like ABS, just as you would test the brakes on a new bike!
Hora, what you might be experiencing is the ABS testing itself. ABS will periodically to check that the system is working. This is normal. On my car sometimes you can feel the pulses through the pedal even when full ABS is not engaged.

Posted 3 years ago #
druidh - Member

CHB - Member

just assumed that any owner of a new car will try out things like ABS, just as you would test the brakes on a new bike!

Much as I was suggesting above then.

Posted 3 years ago #
kennyNI - Member

The maximum braking in soft snow is acheived by locking wheels (just the front, once the rears lock you WILL spin) so a wedge of snow builds up in front of the tyres and provides the stopping force (similar in gravel). But not possible in modern cars, where ABS in nearly standard. WHich for majority of cases is better. This is incorporated into all sorts of DSC, ESP, ASC etc. all of which act differently across different cars. Go and test them out in an appropriate legal place (probably a dedicated skid pan session), its fun as well.

In snow my car will not move with DSC on, so 1st stage is turned off (traction control) to get moving, then turned back on once in motion (even tells you to do this in the manual).

Even knowing this, I still nearly managed to take out the local post box, on black ice at 5mph. Tried all gently, gently approach, nothing happening, so just thought **** that, stood on brakes and let the electronics take over.

Posted 3 years ago #
jfeb - Member

jfeb - thank you. you have just saved me replacing the cv joint on my passat.... [:D] Cheers,

You're welcome

Posted 3 years ago #
FunkyDunc - Member

How sensitive the ABS system is varies completely from car type to car type.

I used to have a Ford Focus and the ABS was way too sensitive and there was no way you could left foot brake because the bloody ABS would kick in.

My current MX5 has ABS but in normal driving conditions it barley ever kicks in, but this morning it kicked in just as easily as any other car would because there is so little grip on snow.

It was also interesting trying out the DSC system this morning. Even that couldnt cope at times and was locking fron wheels to keep the car going in a straight line. How with it off it was much more fun

If you READ the manual of your car it does say ABS makes the car take longer to stop on snow. IMO to have scared yourself that much, and that you couldnt stop in time you were going way too quick for the conditions!

Posted 3 years ago #
coffeeking - Member

Hora, what you might be experiencing is the ABS testing itself. ABS will periodically to check that the system is working. This is normal. On my car sometimes you can feel the pulses through the pedal even when full ABS is not engaged.

ABS should never activate in normal conditions. Self-tests are done at start-up and the first stint of low speed, after ~5mph the control unit tests and calibrates the wheel speed sensors and is ready to go, at no point should the pump be cycling. Some cars do just have stupidly ABS-happy systems. I have noted that having corroded discs plays a massive factor (obviously) and that the ABS on my peugeot kicked in rediculously early until I changed the discs when I noticed the rear faces had built up some rust.

Posted 3 years ago #
paddlemyowncanoe - Member

Mine does that too. I love it - it means it's working. That means I can drive even faster in treacherous conditions.

I like the idea (? on Clarkson) from a few years ago that the best way to improve our driving would be to remove the abs/airbags/seatbelts etc and put a fricking great spike in the middle of the steering wheel. We might pay attention then.

Posted 3 years ago #
samuri - Member

and because I've not seen anyone mention it yet (only skimmed), brake pedal judder when the ABS activates is completely normal, not any indication of a fault.

But yes, ABS is pants on sheet ice and snow, brake smoothly and anticipate and if you start skidding do your own ABS.

Posted 3 years ago #
molgrips - Member

If your ABS is working properly, then when you feel you're not stopping it's because you would be skidding all over the place if you didn't have ABS. ABS should stop you from skidding.

And I learned to drive in a Fiesta with no ABS, really thin tyres, crap traction and terrible understeer. I know how to handle these things, but I would still rather not have to. Just because you can feather brakes doesn't make you some kind of infallible ultra hard-man, so stop flattering yourselves.

Didn't formula 1 cars have ABS for a while before they banned it because it was too much of an advantage?

Posted 3 years ago #
GrahamS - Member

I like the idea (? on Clarkson) from a few years ago that the best way to improve our driving would be to remove the abs/airbags/seatbelts etc and put a fricking great spike in the middle of the steering wheel.

I think you attribute far too much intelligence to Mr Clarkson.

I first heard it mentioned by John Adams in his 1995 book "Risk", where he speculates that if all cars were made from cardboard, fitted with crap brakes, a sharp spike in the steering column and the roads were made of Teflon then there would be no impact on road deaths but a substantial decrease in the efficiency of the transport system.

In other words, the supposed "safety" benefits are actually consumed as performance benefits while the risk remains fairly constant.

Posted 3 years ago #
GrahamS - Member

Which, incidentally, is basically the same argument as the old risk compensation argument of "helmets make you feel safer so you end up taking greater risks"

Posted 3 years ago #
neverfastenuff - Member

Had not had ABS come on once in 4 yrs of driving my car:::
I seem to not over drive my vehicles, probably why it shocked me when the ABS did kick in - but it took very bad road conditions, and to put the point across again - I was approaching traffic lights - I let the vehicle slow down way before and only braked as necessary from 10mph, I was totally caught out by the noise, vibration and the fact that the actual stopping distance increased to the point I thought I was going to overshoot the stop line... it was damn scary..

Posted 3 years ago #
aP - Member

There was a study carried out in Germany with taxi drivers where one set were told that they had ABS, and the others were told that they didn't.
Guess which group had noticeably more accidents?

Posted 3 years ago #
Drac - Moderator

Details of the accidents please.

Posted 3 years ago #