fcuked

I always thought that when your wheels are locked you will come to a complete stop faster than a car with ABS, however some guy is saying that cars with ABS, especially new ones have been proven over and over to stop faster than cars with non abs in a straight line?

CivHizzle

ugh if you lock your wheels up you will keep sliding... abs makes it so they dont lock up by rapidly pressing on the brake pads against the rotars so they wheels dont lock up.

Draco

Tires generate more rolling friction than static (not moving) friction. Period. Back in the days before ABS, drivers had to have the skill to threshold brake, braking just hard enough not to lock up the tires.

Needless to say, not everyone could master this technique, or even remember to use it in "Oh, ****" situations. So back in 1978, Bosch developed an electronic system that monitors the speeds of the wheels and when it senses that one or more wheel is rotating slower than the others (a condition that will bring it to lock), moves the valves to decrease the pressure on the braking circuit, effectively reducing the braking force on that wheel, preventing lock. They dubbed this ABS.

Now, because it is computer controlled, it isn't as effective as the well trained foot of a skilled driver. However, its is very, very close to the same effectiveness, therefore, you'll see ABS in use even in racing circuits, because entering a turn, you can just mash on the pedal and it'll brake perfectly, leaving you free to concentrate on other aspects of driving.

I hope this answers your question.

fcuked

But wouldn't locking up the wheels create more friction between rubber/ground and in order stopping it faster??? I myself don't know, that's why would like some type of a reaonable detailed explanation.

MaxSterling

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1.8 HB &raquo;</TD></TR><TR><TD CLASS="quote">I always thought that when your wheels are locked you will come to a complete stop faster than a car with ABS, however some guy is saying that cars with ABS, especially new ones have been proven over and over to stop faster than cars with non abs in a straight line?</TD></TR></TABLE>

locking up stop faster but you lose steering control if you lock wheel which is dangerous. so yes you stop faster w/out abs

fcuked

Ok let me make this clear. The argument isn't which is better for daily driving.

I want to know the following:

What stops faster in a STRAIGHT line, car w/abs or car with brakes locked up.

b16si

No offense but damn dude thats a dumb question. Of course your are not going to stop faster when your wheels are locked up and slinding accross the ground. Do you accelerate faster when you burn out no. Contact between ruber and street = GOOD

sramDcivicEK

locking ur wheels is no fun. when i did it, my steering wheel locked up too. had no control over the car, thats why i ended up into a curb

Draco

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1.8 HB &raquo;</TD></TR><TR><TD CLASS="quote">Ok let me make this clear. The argument isn't which is better for daily driving.

I want to know the following:

What stops faster in a STRAIGHT line, car w/abs or car with brakes locked up.</TD></TR></TABLE>

Car w/ ABS. Rolling friction &gt; Static friction. Can't argue with physics.

dsadas89das78934

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Draco &raquo;</TD></TR><TR><TD CLASS="quote">

Car w/ ABS. Rolling friction &gt; Static friction. Can't argue with physics.</TD></TR></TABLE>


what i believe you are trying to say is that the coefficient of static friction (NOT sliding) is greater than the coefficient of kinetic friction (sliding)

&lt;&lt; physics minor


anyway... ABS makes things much easier for the driver... so, in real world applications, ABS would stop shorter. in gravel or sand, non-abs cars stop quicker because, as the wheels slide, a mound of gravel/sand builds up in front of the tire adding to the force slowing the car

Outrun

Simple answer, ABS.

Compex answer regarding ABS in rain, snow, etc. Many people think they will stop in a shorter distance in adverse conditions. What they don't realize is that ABS in adverse conditions is meant for the driver to retain STEERING CONTROL while braking, as opposed to locked up fronts.

Some people brought up the idea that sliding tires have more friction. Well, look at an FWD car doing a rear wheel drift. A drift is a controlled LOSS of traction. What is the rear wheel doing when an FWD car is doing a rear wheel drift? Is it rotating or is it stopped? The rear wheel is stopped, and the car is drifting because there is LESS traction at the rear.

But that is not the point of this thread. So in a straight line, the ABS car will probably be more consistent. I've seen magazine tests in Car and Driver or Road and Track where the non-ABS car may have slightly better straight line dry braking than its ABS counterpart, and vice versa.

dunkd

stupid question. why would ABS exist if it wasnt better?

Outrun

Like I said before, one of the main benefits of ABS is to retain steering control during a situation that requires maximum braking (what some manufacturers refer to as a "panic stop.") You can't steer if your front wheels are locked up.

The Internet Tough Guy

in my physics book, there was a problem on friction, which had a little bar graph of stopping distances: amateur driver with no abs was huge, amateur driver with abs was smaller, professional driver with no abs was even smaller than that. so if you know what you're doing, and won't **** the bed when the time comes, there is no need for abs whatsoever. you just have to know when the wheels are going to lock up, then you let off and modulate quickly.

CivicFerioSiR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jwn7 &raquo;</TD></TR><TR><TD CLASS="quote">in my physics book, there was a problem on friction, which had a little bar graph of stopping distances: amateur driver with no abs was huge, amateur driver with abs was smaller, professional driver with no abs was even smaller than that. so if you know what you're doing, and won't **** the bed when the time comes, there is no need for abs whatsoever. you just have to know when the wheels are going to lock up, then you let off and modulate quickly.</TD></TR></TABLE>

was this in wet or dry weather?

Team 4R

a skilled driver that is threshold braking will stop a non-abs car faster in a straight line.... final answer. just think about it...... let's assume two exactly identical cars with exactly identical drivers are decelerating with exactly the same braking pressure.... the non-abs system applies that negative acceleration force at a constant and steady pressure until the car is stopped. the non-abs unit will "pulse" the pressure so that it is not constant... as a result, it will take longer to stop the car.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dunkd &raquo;</TD></TR><TR><TD CLASS="quote"> stupid question. why would ABS exist if it wasnt better?</TD></TR></TABLE>

THIS is the stupid question..... abs only exists because there are way too many idiot drivers out there........ if there was no abs people would just be sliding all over the place.

The Internet Tough Guy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CivicFerioSiR &raquo;</TD></TR><TR><TD CLASS="quote">was this in wet or dry weather? </TD></TR></TABLE>

dry. interesting huh? instead of wasting money on an abs system, put it toward a driving course.

BallHawk3

I like Draco's explanation. And I think its so true too about threshold braking. If you now how to use the brakes without the wheels locking up, it works a lot better. ABS is like more of a "lazy" way. You don't have to think about it, you just mash the pedal. Its easier to use.

But if you tend to lock up the tires and then the car slides. Thats a different story. What you probably heard, the person probably meant, if the person knows how to use the threshold braking on a car without abs, it will stop better than a car with abs. But yes you can lock the wheels on a car without abs and slide, and that will make you stop at a longer distance.

FlatBrokeHatch

here is a thought i just had...

Automatic vs. Manual

An automatic car at idle will roll with the foot off the break...would any of that force keep the automatic car rolling a tad bit longer?...prolly not enough to calculate...but it made me think a lil bit.

ekb18cCivic

ok in rivers ed they teach you about this... non abs cars have a shorter stopping distance BUT!! if the wheels lock up you have no control over the steering... abs allows the you to have control over the steerin so while stopping you can avoid what is infront of you not just slow down faster sometimes the mobility of abs is needed.. so abs is better if you are about to rear end someone..

xerox445

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Draco &raquo;</TD></TR><TR><TD CLASS="quote">Tires generate more rolling friction than static (not moving) friction. Period. Back in the days before ABS, drivers had to have the skill to threshold brake, braking just hard enough not to lock up the tires.

Needless to say, not everyone could master this technique, or even remember to use it in "Oh, ****" situations. So back in 1978, Bosch developed an electronic system that monitors the speeds of the wheels and when it senses that one or more wheel is rotating slower than the others (a condition that will bring it to lock), moves the valves to decrease the pressure on the braking circuit, effectively reducing the braking force on that wheel, preventing lock. They dubbed this ABS.

Now, because it is computer controlled, it isn't as effective as the well trained foot of a skilled driver. However, its is very, very close to the same effectiveness, therefore, you'll see ABS in use even in racing circuits, because entering a turn, you can just mash on the pedal and it'll brake perfectly, leaving you free to concentrate on other aspects of driving.

I hope this answers your question.</TD></TR></TABLE>

Actually ABS was first developed before 1978. Bosch may have brougut it to the car market, but it was designed for aircrafts. The Anti Lock Brake System was first implimented on a few large military aircraft. It was then brought over to the commercial airline industry. Only then after many years on planes was it brought over to Autos. Just a little tid bit of info

NonovUrbizniz

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Draco &raquo;</TD></TR><TR><TD CLASS="quote">Tires generate more rolling friction than static (not moving) friction. Period. Back in the days before ABS, drivers had to have the skill to threshold brake, braking just hard enough not to lock up the tires.

Needless to say, not everyone could master this technique, or even remember to use it in "Oh, ****" situations. So back in 1978, Bosch developed an electronic system that monitors the speeds of the wheels and when it senses that one or more wheel is rotating slower than the others (a condition that will bring it to lock), moves the valves to decrease the pressure on the braking circuit, effectively reducing the braking force on that wheel, preventing lock. They dubbed this ABS.

Now, because it is computer controlled, it isn't as effective as the well trained foot of a skilled driver. However, its is very, very close to the same effectiveness, therefore, you'll see ABS in use even in racing circuits, because entering a turn, you can just mash on the pedal and it'll brake perfectly, leaving you free to concentrate on other aspects of driving.

I hope this answers your question.</TD></TR></TABLE>

I agree with you on everything but the bold bit...

It's not the computer control that makes it less effective, it's poor programs and components.... For example... the sensors "over-sense" the wheel spin... and the abs unit "over-pumps" the brakes... if it was more of a what's needed when system instead of an "oh ****" system it's computer control would TOTALLY outperform even the most experienced foot.

An ABS system that monitored and sent custumized pressure to all 4 wheels independently would outperform the most talented driver in the world in a standard "proportion valved" braking system.

I believe some of the new BMW's have a system like this that actually used brake pressure to certain wheels in a corner to attain better stability and traction in corners... like heel-towing but without the negative effects of brake pressure to all 4 wheels. I'm sure their ABS system is heading to a more dynamically computer controlled system... instead of an abs on or off type system that we're all used to.

Just some thoughts.

idumpwitmy12gaugepump

i like non abs, sometimes, you can do more without it.

NonovUrbizniz

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by idumpwitmy12gaugepump &raquo;</TD></TR><TR><TD CLASS="quote">i like non abs, sometimes, you can do more without it.
</TD></TR></TABLE>

I agree... I've never felt the want for ABS except a couple of times all of which were such low traction situations it wouldn't have helped much if at all...