A few questions I have been rattling around my noggin.

Say you have 2 identical cars

One has ABS and one does not.

Can the car without ABS stop faster than the car with ABS (given the driver does not lock up the brakes)

My logic is.....

without ABS the driver could use the brakes up to just the point before locking them.

With ABS (assuming the ABS system kicks in quickly) the brakes lock then unlock then lock then unlock, which is the equivalent of pumping the brakes.

It seems to me it would take more time to pump brakes than smoothly apply force.

Now just focusing on the car with ABS......

even though ABS is supposed to get you to stop in the shortest amount of time without locking up the brakes.... would you be better off smoothly applying brakes to stop or slamming on them and letting the ABS sort it out.

It may be a mental thing but I "feel" like the car stops faster if you can smoothly apply the brakes than letting the ABS do its job, because I feel like even when ABS is "working" there is still a skidding sensation were as staying out of the peddal territory where the ABS kicks in is actualy more efficient.


Yea its been a sloooooowwww day at work

 

 

The two cars are 350Z's! Now STFU

 

Whats for lunch?

 

Do you walk to work or bring your lunch?

 

Pasta.... from Viga! This braking information is vital. I want my lunch 0.525 seconds faster!

Sure I could leave 0.525 seconds earlier, but wheres the rush in that!

 

My guess is the car with ABS will stop faster because the sample rate of the sensors and the reaction time/rate of the computer will be quicker than any human response...

Have you ever braked in the snow with a car equipped with ABS? Humans can't control which wheels to lock/unlock.

 

since when does a 350Z not have ABS? (ABS is standard)

 

Most people who can actually stop faster without ABS are racing cars on the weekend. Few average street drivers can do it , and even a lot of the weekend racers can actually do it.

 

Police Interceptors do not have ABS so they can stop faster.

ABS usually takes more distace to stop a car that one without.

 

^Thanks, I was wondering why some race cars go without ABS, unless it is part of the rules not to have it

 

Just slam on the suckers!

 

Ok this is a stretch but say you take Forza 2 with the same car with ABS on and slam on the brakes one time and then apply smooth pressure the next, I find you stop faster when not slamming on the brakes

I have fully prepared myself for 3 out of every 4 responses to reply : or

So i just need one out of the 4 of you to post a real reply then I will be like

 

you stop in shorter distance when you make smooth inputs because it allows the weight transfer to increase the grip on the front tires.

if you slam the brakes immediately the front tires have less traction since there is less normal force on the braking surface (the tires haven't loaded up yet)... so your tires will lock up in that instant.

as for abs... it takes a lot of skill to threshold brake all the time. abs will prolly be better for most. it's kinda nice on the track because it's a good prevention of flat spotting a tire.

if you are perfect and can threshold brake EVERY single time while heel toe downshifting, then having no abs will be better.

edit: oh yeah, the cool thing about abs on a street car is it allows you to steer when the average joe panic slams on the brake pedal. you do that in a non-abs car and your car will plow straight if your tires are locked up. i worked at an auto company and our driver training had this for an exercise. it was a revelation to me at that time

 

some good info at the link below, a decent read for those with more questions.


http://auto.howstuffworks.com/auto-p...lock-brake.htm

 

Ahhh the weight transfer makes a lot of sense, thank you. Yea no ABS is good on a race track because you can pick and choose your line most of the time, but on the street with people cutting you off left and right, most times you dont have the luxury to brake in a straight line

 

^awesome thanks

 

The answer to your question relies on two concepts: traction and threshold braking. The 'best' way to stop in any situation is to use threshold braking, or as you say smoothly apply the brakes until the point right BEFORE you would break traction and slide. So in any situation, ideally it would be better to not use the ABS system if possible. Brake sooner. HOWEVER: We are human. We screw up. We misjudge distances and don't see patches of black ice. We apply too much or too little braking pressure. ETC. The nice part about ABS is that when we screw up, it kicks in and "pumps" the brakes hundreds of times faster than we would be able to. Now you definitely can and should use threshold braking on a car equipped with ABS, but it is like a failsafe system: If you screw up there is still a good possibility that ABS will allow you to stop in time to avoid hitting something or ending up in an unsafe situation.

 

I've read a very good article on abs vs not-abs, but unfortunately I can't remember where it was to link it.

A little thing I do remember however is that an ABS equipped car will generally stop faster than a non-ABS car. If you can perform such a perfect threshold braking without ABS that it wouldn't lock the wheels, you can do it in an ABS controlled car too. ABS won't "jump in too soon" if you don't lose traction.

Now, the one exception to this rule, as far as I can remember, is driving on gravel or other loose surface, in which situation locking the wheels will cause a small amount of gravel to form in front of the wheels which, in turn, help it stop faster.