ABS delete?

[v1c10us]

Jesus Christ this thread is a disaster.

Although I am far from being a braking expert, I teach Evasive and Defensive Driving Courses for Senior Executives, Executive Protection drivers, etc. I will therefore put my .02 in...

The fastest way to stop a car is to brake at the limit of the tires, if you pass this limit, the tires will lock up and you'll start sliding.

ABS works by decreasing line pressure to the tire that locked up allowing it to roll. Once it senses this, it allows the line pressure back to the caliper at whatever force you're applying.

If the tire locked up, ABS released pressure, yet your foot is still to the ground, guess what, the tire is gonna lock up again when the ABS sends the line pressure to the caliper again. ABS does this many times a second, faster than what 99.9% of people can possibly do.

Whether or not ABS is a good thing depends on how good of a driver you are and what the goals for the car are. But I will say this, a sliding car will never stop faster than a car who's driver is pumping the brakes at a rapid rate.

This whole talk about sliding tires melting and creating friction is all BS.

To the OP, if your car has ABS and you are pumping your brakes then you are doing it wrong.

You guys might want to do a little reading on ABS and how it works before you start pulling your ABS fuses...

You may want to look into the actual physics of it.
Unless you have tires capable of with holding massive amounts of grip the rolling resistance of a tire at its threshold is almost always less than the sliding resistance of the tire; fact.
edit: as for using the abs, it pushes against your feet because it wants you to brake at the threshold, not slide uncontrollably and cause an accident, its all for controllability's sake.
Modern braking systems in high end cars allow the tires to slide in a controllable fashion using shit tons of computers. the new evo for instance when in a straight line will lock up the brakes and when one of its yaw sensors detects something awry it will reduce braking force to correct your direction and then allow the tire to lock up again.

[Zzyzx]

You may want to look into the actual physics of it.
Unless you have tires capable of with holding massive amounts of grip the rolling resistance of a tire at its threshold is almost always less than the sliding resistance of the tire; fact.

Tires rolling = Static Friction
Tires Sliding = kinetic friction

To quote Wiki on Static Vs kinetic friction

Friction forces are categorized as either static or kinetic. The coefficient of static friction μs, characterizes friction when no movement exists between the two surfaces in question, and the kinetic coefficient μk, characterizes friction where motion occurs. While static and kinetic friction differ in value (the coefficient of static friction typically being greater than that of kinetic friction), both result from the electric force acting on microscopic irregularities in two adjacent surfaces

So Physics states that a rolling tire should have a greater coefficient of friction with the ground then a sliding tire. which contradicts your statement of "fact".

http://en.wikipedia.org/wiki/Coefficient_of_friction

[4angrybadgers]

its only in manually pumping the brakes versus electronic pumping that the abs helps you with the exception of odd circumstances such as rain and very dusty roads.
It boils down to this, If the rolling resistance including the brakes is greater than the resistance of the sliding tire then ABS will help you.
But since this is only true when there is something interfering with the tires contact with the ground such as fine dust or gravel or wetness or ice or some very very very cracked up roads with little contact to the wheel to begin with, for the most part the abs increases braking distance in a straight line.

That is the critical flaw in your argument. As Zzyzx pointed out, the static coefficient of friction is greater than the kinetic coefficient of friction. A tire with a contact patch static relative to the road (a rolling tire) will always have more grip than one sliding merrily along. It's been proven by decades (centuries?) of scientific research.

[v1c10us]

See, Rolling resistance in wikipedia.

[Zzyzx]

See, Rolling resistance in wikipedia.

We're not dealing with rolling resistance here. We are dealing with Kinetic Friction (the tire sliding) Vs Static friction (the tire rolling)

now if we were trying to figure out how quickly the car would slow on its own based on tire size or how much energy is expended in keeping a rolling tire moving... then Rolling resistance would apply. But we aren't.

Were talking about how much friction there is between rubber & road depending on if that rubber is sliding across that road or Not. and physics states that there is more friction when the rubber is not sliding Vs is.

it takes more force to make surfaces start sliding over each other than it does to keep them sliding once started.

[classiccelica]

I am not sure who you are talking to when you said this but can you please think about what you said.

pumping your brakes does not increase your stopping distance? SO once you put your foot on the pedal and then take it off the rate of deceleration does not change? Seriously re-read what you said.

There are a lot of reasons given for pumping brakes. Originally it was to pressurize the system other reasons... to warn the driver behind you, to keep the car from hydroplaning, and to keep the wheels from locking up.

If you decide to pump your brakes and I am driving behind you, I am going to be very sad when you decide to warn me by pumping your brakes and you end up in the back seat of the vehicle in front of you... but wait i forgot, pumping the brakes does not increase your stopping distance.


I also am not sure if we are all on the same page when we are saying pumping the brakes. I am sure everyone means cadence braking which is a series of fast and short wheel lock ups.

I never once said that pumping the brakes makes you stop quicker

[abstract]

what about the weight loss..???..??

think about losing weight on these heavy ep3's!!!

id get a abs delete kit in a second if they had 1

[musashi1219]

Now you're changing your story.
.

Not at all, I jsut clarified myself.

I guess I'm stupid or something, so just humor me, but doesn't ABS stand for Anti-lock Braking System? Again, I'm probably wrong, but just wanna know.

You are correct, but when asked why abs is so nice that is the reply you get from a lot of people. like an alternate acronym.

Jesus Christ this thread is a disaster.

I agree, and thank you for speaking up in the thread

I never once said that pumping the brakes makes you stop quicker

I do not believe I said you did sir, but given the amount of crap that has been slung in the thread you may have been caught in the crossfire.


Zyxx thanks for bringing some knowledge into the thread.


Adrian and Zyxx why do people insist on thinking the brakes are the most important part of stopping a car?

[abstract]

what about the weight loss..???..??

think about losing weight on these heavy ep3's!!!

id get a abs delete kit in a second if they had 1

weight loss potential????????????????

[v1c10us]

We're not dealing with rolling resistance here. We are dealing with Kinetic Friction (the tire sliding) Vs Static friction (the tire rolling)

now if we were trying to figure out how quickly the car would slow on its own based on tire size or how much energy is expended in keeping a rolling tire moving... then Rolling resistance would apply. But we aren't.

Were talking about how much friction there is between rubber & road depending on if that rubber is sliding across that road or Not. and physics states that there is more friction when the rubber is not sliding Vs is.

Okay, if this doesn't shut you guys Up i'll have to get really technical.

"Occasionally it is maintained that µ is always < 1. While in most relevant applications this is true, having a µ > 1 merely implies that the force required to slide an object along the surface is greater than the normal force of the surface on the object. For example, silicone rubber or acrylic rubber coated surfaces have a coefficient of friction that can be substantially larger than 1."
This includes tires, which means if tires were made of wood what you are saying is correct, but since they are not, it is incorrect because µ is greater than 1 not less than 1

Also you have to take into account that the normal force is being varied by the brakes, its not constant because the brakes are not an ON OFF machine;
Since the friction force is a product of the kinetic friction and the normal force. Since the FULL normal force is being applied when the brakes are locked up the frictional force is greater than when the normal force is not being fully applied in order to keep the tires rolling, this reduction reduces the elements in the equation and results in a lower product, or in this case a lower frictional force.
edit: it would be different if the brakes were always fully applied, you would have equal forces at work, but due to the increased force and the decreased sliding friction it equates to the sliding friction of the tire being slightly greater than the rolling friction.
You also have to take into account the maximum static friction the 2 materials can attain, but thats not really relevent because its not very much.

[oldskoofame]

ABS does not increase your stoping distance nor does it make you stop sooner, all abs does is eliminate the brakes from locking thusly giving you more control to steer the car out of the way.

wrong.

[abstract]

weight loss potential????????????????

anyone??

[v1c10us]

Adrian and Zyxx why do people insist on thinking the brakes are the most important part of stopping a car?

Because without them it doesnt matter how much grip your tires have, if you remove the brakes the car wont stop. I agree that even if you have the best braking system in the world but crappy tires its all for naught.

[musashi1219]

The point being that brakes are not the most important part of the equation. Most brake upgrades do nothing to stop the car better. The upgraded tires do that. Now please instead of making uneducated statements go back and read some of the posts in this thread. You have a bad habit of getting into a thread and spouting off incorrect information and then getting argumentative when everyone does not believe you.

[v1c10us]

Sorry but i've read every post in here and its all correct in theory(for the most part) but wrong in practice.
I've posted all the information I can supply and have no intention to argue further, if someone really wants I'll do a video confirmation with time to allow for brake cool down.
One with my ABS fuse removed threshold braking, one with it in, and one with it removed and letting the tires slide, I'll use whatever format for display you guys think is fair.
There wont be any doubt that I'm cheating on the braking method because my tires will be. sliding, not sliding, and displaying the obvious characteristics of ABS. I'll do the braking from the top of second gear once I hit the rev limiter with a constant camera with no cuts, etc.