ABS & Non ABS Cars

Shadow_2k5

story all

I recentley got a Fabia shes a good Motor & Im well inpressed with her but she none ABS & Im a little worried when the bad weather hits us. Just wondering this.
I was told its More Dangerious to Drive in snow & Ice Without ABS is this true ?
Im aware Driveing in ICE & Snow is Dangerious any how.
if you haven Decent tires & A decent set of Brake pads its a little safer?

ds20prefecture

ABS prevents the wheels from locking under hard braking. This allows you to continue to steer the car while braking hard as well as stopping the car sooner.

The wheels are inclined to lock when the friction of the brake pad to the disc/drum overcomes the friction of the tyre to the road. So if the friction of the tyre to the road is reduced, for example with bald tyres, or an icy surface, the wheels are much more inclined to lock.

So yes, your braking will be safer on wet/icy/snowy roads with ABS than without. You can improve the safety of a non-abs car with winter tyres or if you live in extreme conditions, chains for the tyres.

Ireland doesn't really get severe winters - occasionally we have some patches of ice or a light dusting of snow. In bad conditions, give yourself more braking distance between you and the car in front - if they have ABS they'll stop quicker than you can. Also familiarise yourself (somewhere safe) of when and how your wheels lock up. When you feel them lock up, pump the brake pedal a little to keep them rotating but slowing. This is all that ABS systems do, although they do it a lot faster than a human can. Mostly, adjust your speed for the conditions.

BTW - my car has no ABS and I have yet to miss it. I have never unintentionally locked up my front wheels.

Ernie Ball

My ABS saved my ass TODAY. I was distracted (my bad) and didn't notice that the car ahead had stopped. I jammed on the brakes and the car stopped on a dime. First time I've felt the ABS come on. A non-ABS car with me driving it today probably would've hit the car in front of me.

bmoferrall

There's a section on ABS here.

Shadow_2k5 wrote:

I was told its More Dangerious to Drive in snow & Ice Without ABS is this true ?
Im aware Driveing in ICE & Snow is Dangerious any how.

Only really relevant if you travel abroad but, from the above article:

Personally I don't like ABS. I don't like the idea of a computer interrupting the connection between my right foot and the brakes. It also doesn't work worth a damn on gravel or in the snow. With regular brakes, in the snow, you can jam them on and at least stand a chance of the tyres digging in and finding the road surface. With ABS the system will just take the brakes off and you'll skate merrily along on the snow with no chance of slowing down.

green-blood

actually ABS on ICE and SNOw will give you a much LONGER braking distance!!!

MrPudding

green-blood wrote:

actually ABS on ICE and SNOw will give you a much LONGER braking distance!!!

That is interesting as it is in direct contradiction to a test carried out on a frozen lake by Tiff Needell on 5th Gear. He tried breaking without ABS and with ABS. Wothout ABS the car behaved, well, like it was on ice. With the ABS he was able to bring the car to a controlled stop without the wheels locking.

MrP

Ernie Ball

MrPudding wrote:

That is interesting as it is in direct contradiction to a test carried out on a frozen lake by Tiff Needell on 5th Gear.

It's also in contradiction with this. 'Interesting' is not the word I would've used.

Wibbs

On ice a car with ABS is significantly better at stopping than one without. I could see where there just might be a problem on deep snow. Then again if you're going that fast on deep snow, you're being a bit silly anyway.

However, my own personal experience of deep gravel braking with ABS left me with a bit worried. As pointed out, it didn't dig in and just skated merrily along the top. That said, it's a rare situation and all things being equal ABS is better.

IMHO too many people nowadays expect a cars technology(ABS/traction control/intelligent steering and all that stuff) to somehow make up for bad driving skills. The design of some cars isolates the driver from the fact that they're hurtling along in a potentially dangerous situation. Once upon a time, you knew you when you were doing 80mph. Now you may as well be sitting in your armchair at home with a virtual reality landscape drifting by. While I don't want to go back to the bad old days, I do think people should be aware of how dangerous driving actually can be. If you could feel what it's like to be in even a low speed crash, I think most who had that experience would be a lot more careful on the road.

ds20prefecture

green-blood wrote:

actually ABS on ICE and SNOw will give you a much LONGER braking distance!!!

On ice, no. ABS is better. Studded tyres are much better again.

On snow (and I suppose gravel) there is advantage to not having ABS - if the wheels lock on powdered snow, a snow drift builds up in front of the tyre and acts as a wedge. The snow-on-snow friction will slow you down. If you have ABS, you'll roll over this wedge with every pulse.

Even on the continent where they get proper snow, you are much more likely to be driving on hard-packed snow than fresh powder, so most of the time ABS is an advantage, but still no substitute for chains/studs. If you are speeding on gravel, you should be in a rally car with special gravel-stage tyres. If you're speeding on the driveway to your country mansion, then be it on your own head, but Jeeves will tut-tut.

In Ireland (where people panic at the first sign of rain, never mind frost or ice) ABS makes for shorter stopping distances.

I'm very surprised the Fabia doesn't have it. It's standard on all Octavias.

Idleater

Shadow_2k5 wrote:

story all

I recentley got a Fabia shes a good Motor & Im well inpressed with her but she none ABS & Im a little worried when the bad weather hits us. Just wondering this.
I was told its More Dangerious to Drive in snow & Ice Without ABS is this true ?
Im aware Driveing in ICE & Snow is Dangerious any how.
if you haven Decent tires & A decent set of Brake pads its a little safer?

By definition a non ABS car will stop quicker and in a shorder distance than a non-ABS car. The difference between two identical fabia's (one with and one without ABS) stopping in non ideal road conditions is the way that each driver applies the brakes.
If one applies the brakes in a non ABS car in the manner that they would in an ABS enabled car than the car will more than likely skid.
The other distinct distinct difference between ABS and non-ABS is the feel that you get from the pedal. Without ABS, you will be able to determine the point of maximum breaking efficiency where otherwise, you would feel like you are pressing your foot onto a sponge.

So, in answer to your question, you will have to decide how you are going to use the brake pedal. If you are used to stomping onto the pedal from an ABS enabled car, then, yes, you will most likely skid the car, but if you apply pressure to the pedal and react to the road and how the car and wheels are interacting, then you will have no problems.

Macy

Bloody youngsters.... Those of us old enough managed to learn and drive in the pre abs days no problem. ABS is a help, not a necessity. Christ, you'll be wanting help turning the steering wheel next....

SouperComputer

The other distinct distinct difference between ABS and non-ABS is the feel that you get from the pedal. Without ABS, you will be able to determine the point of maximum breaking efficiency where otherwise, you would feel like you are pressing your foot onto a sponge.

ABS has has nothing to do with a spongy pedal or feel. That is all to do with the servo, hydrualics pads disks fluid. The ABS system has no effect until the wheel motion sensor detects a wheel about to lock. Spongy brakes means you have dodgy seals or air in the hydraulic system.

You can very simply determine the maximum efficiency of the breaks. When you lock the wheels, not only do you get an audio warning but it will almost feel like the car has sped up.

Personally, I hate the feeling when ABS comes on. Its a real pain if you have one wheel on mud for example, you have to put a lot of stress on the system to make use of the traction available on the other wheel.

I Much prefer cadence breaking, which is better if practiced enough. Only thing is when you get into a sticky situation, you dont always have the presence of mind to cadence brake effectively. That's where ABS is handy to have. Also as someone else said, turning to take evasive action while breaking requires a lot less skill and presence of mind with ABS

To be honest, I wouldnt worry too much as to weather a car has ABS or not. At the end of the day, breaking in a shorter distance is not always the safest as you run a further risk of being rear-ended.

Spend your money on a skid school

unkel

@OP: FWIW, all cars sold in Europe now have ABS

Snow / ice are largely irrelevant in Ireland. When not using snow chains, a driver should be extremely careful, ABS or not, 4WD or not, or what else or not

ds20prefecture wrote:

ABS prevents the wheels from locking under hard braking. This allows you to continue to steer the car while braking hard as well as stopping the car sooner

Perfect synopsis

One angle missed in the discussion so far is the weight of the car. My first car with ABS was a relatively small and light Nissan Primera (1100KG). The only time the ABS system kicked in was when I tried to see if it was working. My second car with ABS was a BMW 5-series (1500KG). There was one incident when I would have crashed without ABS when a Garda car cut across me from a side road. The brakes on that car were excellent (the NCT tester said he had never tested a car with better brakes). The ABS system kicked in a few times per year. The brakes on my current car, a 7-series (2000KG) are just something else. The ABS kicks in at least once a week though

As a side note, a very talented professional race driver can get almost the braking performance of an ABS system. You and I can not...

bmoferrall

unkel wrote:

As a side note, a very talented professional race driver can get almost the braking performance of an ABS system. You and I can not...

Indeed, I remember reading a long time ago that one of the things which set Senna apart from his peers, particularly on wet tracks, was his superior use of 'stab' or cadence braking.
I've been (clumsily) trying it ever since (in the hope that it minimises brake fade and lengthens their life).

unkel

bmoferrall wrote:

Indeed, I remember reading a long time ago that one of the things which set Senna apart from his peers, particularly on wet tracks, was his superior use of 'stab' or cadence braking

That's a most interesting point that is new to me. I used to be into F1 until the '83 (I might be off a year or two there) Monaco GP in the rain. Senna's performance was amazing, overtaking on a circuit that was deemed to be pretty much un-overtakable. The race was stopped before the end when Senna was in 3rd place (iirc). I could see no valid reason why the race was stopped at that particular time.

Desillusioned and semi-paranoid, I have not seen a complete F1 race since

bmoferrall

unkel wrote:

That's a most interesting point that is new to me. I used to be into F1 until the '83 (I might be off a year or two there) Monaco GP in the rain. Senna's performance was amazing, overtaking on a circuit that was deemed to be pretty much un-overtakable. The race was stopped before the end when Senna was in 3rd place (iirc). I could see no valid reason why the race was stopped at that particular time.

Desillusioned and semi-paranoid, I have not seen a complete F1 race since

My memory is pretty unreliable at the best of times so it's possible I'm confusing Schumacher with Senna .
After a particularly dominant win (pretty sure it was a wet race) by Senna (or Schumacher) some analysts were trying to figure out why he was so much faster than everyone else.
After analysing the post-race data they concluded that the main contributory factor was his (stab/cadence) braking technique when cornering.
It would be interesting to know who pioneered this technique (presumably in a racing context).

unkel

bmoferrall wrote:

It would be interesting to know who pioneered this technique (presumably in a racing context).

Aye. Anyone out there that could shed some light on this?

Wibbs

I seem to remember this lad used the technique, http://www.ddavid.com/formula1/nuvo_bio.htm A god among men. A champion on 2 wheels and 4. Check out the bit where he broke both legs. The doctors tell him he won't be able to walk much less race and the very next day he straps himself to the bike. He then wins the race. :eek:

So it's been around for a while. It was needed even more back then as drum brakes fade rapidly when compared to disc, so cadence braking was the order of the day, pretty much all the time to stop the brakes overheating.

bmoferrall

Here's one take on the technique:

...Cadence braking???

All to do with managing speed - inertia & angular momentum.

The key here is the TYRES

You are trying to get to the "maximum permativity" of the corner (which changes according to track conditions) so you can maintain the highest possible speed whilst retaining grip.

If you find yourself under the maximum permissible speed through the bend - you loose time and maintain loads of grip.

Above the maximum - and you loose grip and time.

The sweet spot the driver is trying to aim at is the bit in the middle - no loss of grip - highest possible speed depending on setup and conditions.

So ....

What to do ?....

Pitlane management for this consider the Brakes - aerodynamics - the track conditions and the tyres. Those are all points in the setup.

The driver cannot change his setup as he approcahes a bend so has to consider what he CAN manage.
Which is taking the setup/package through the corner at the point just before the tyres are likely to give way to slipping.

Point of Physics The most efficient point of a tyre is the very moment of maximum grip just before it gives way to a slide. ( In F1 the tyre actually mis-shapes the tyre wall and the drivers feel this moment and know just how far they can push it) in GP3/ GP4 Geoff crammond put in tyre squeek to give you an indication of this effect.
This means that the tyre is at its maximum capability to maintain grip - this is the point of tyre performance the drivers are constantly trying to achieve.

What they do to get there depends on bend and circuit - but they mostly use a technique called Cadence Braking.

They dont tend to use graduated braking and they definitely dont stuff the brake pedal through the floor as that will just throw the car into a slide.

Cadence braking is where you pulse the brake pedal with your foot. You beat the pedal on-off-on-off-on-off and so on. This is exactly how Antilock braking works but a kind of human actuated version of it.

The thing is the drivers know how to do this respecting their setup and reaching the most efficient point of the tyre - time and time again before the corner.

You will find you can brake later as you can rake off more speed more quickly.

Blitzkrieger

Technology is the solution : sports ABS. Only behaves like ABS when the wheels actually lock.

Ernie Ball

Blitzkrieger wrote:

Technology is the solution : sports ABS. Only behaves like ABS when the wheels actually lock.

What cars have that?

BrianD3

bmoferrall wrote:

My memory is pretty unreliable at the best of times so it's possible I'm confusing Schumacher with Senna .
After a particularly dominant win (pretty sure it was a wet race) by Senna (or Schumacher) some analysts were trying to figure out why he was so much faster than everyone else.
After analysing the post-race data they concluded that the main contributory factor was his (stab/cadence) braking technique when cornering.
It would be interesting to know who pioneered this technique (presumably in a racing context).

I have never heard this mentioned in relation to Senna you sure you're not mixing it up with the throttle stabbing that Senna was renowned for? This stabbing during cornering allowed him gauge how much grip there was so that he could get back on full throttle as quickly as possible while exiting the corner. I remember seeing a comparison of telemetry from Senna's car and Jonathan Palmer's - they were both with McLaren at the time. The telemetry graphs were completely different - Senna's was a serious of stabs whereas Palmer's was much more progressive but Senna was also a lot quicker

bmoferrall

BrianD3 wrote:

I have never heard this mentioned in relation to Senna you sure you're not mixing it up with the throttle stabbing that Senna was renowned for? This stabbing during cornering allowed him gauge how much grip there was so that he could get back on full throttle as quickly as possible while exiting the corner. I remember seeing a comparison of telemetry from Senna's car and Jonathan Palmer's - they were both with McLaren at the time. The telemetry graphs were completely different - Senna's was a serious of stabs whereas Palmer's was much more progressive but Senna was also a lot quicker

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