I wish people would start understanding basic physics

[Lean L]

With yet another snow storm coming, I keep on hearing warnings from people such as 'It's really bad, I was slipping with my AWD!'.

Yes, it happens people... You can argue that you get more than twice the traction with AWD than FWD during heavy acceleration but the point is moot when it comes to taking a turn too quickly or trying to stop on ice. Any 4 wheel configuration will stop and slow the same way ignoring ABS.

AWD will get you up an icy hill when FWD may fail and RWD will fail but it's not preventing you from sliding back down if you stop.

I hate making analogies but this is akin to saying 'I'm not getting any taller despite taking steroids.' Yes, steroids help you grow just like AWD helps you get around during the winter but it's not supposed to make you taller just like how AWD is not preventing you from slipping.

 

[smackababy]

I'll take the "Hey! I have an AWD, if it goes this quick in snow, it can stop this quick." of the same moronic crap about "ABS takes away my control and causes me to crash." garbage we get in ATG. =(

 

[Miramonti]

I thought I was going to get physics lessons. I'll stick with Khanacademy.org.

 

[mmntech]

My favourite is watching guys in 4X4 pickup trucks fishtailing all over the place on icy roads.

 

[Lean L]

I'll take the "Hey! I have an AWD, if it goes this quick in snow, it can stop this quick." of the same moronic crap about "ABS takes away my control and causes me to crash." garbage we get in ATG. =(

There is one thread that I made that mentioned ABS but that's the only thing that rings true about that statement.

 

[highland145]

70 here...snow not found.

 

[smackababy]

There is one thread that I made that mentioned ABS but that's the only thing that rings true about that statement.

I wasn't intending to point that at you. There are a few people, whom I won't name, that are very against ABS because they believe they are able to control brake locking better than a computer while maintaining optimal traction; one even went so far as to try and "prove" how ABS caused him to wreck, and had he just been sliding out of control with his wheels locked, he'd have been just fine.

 

[Lean L]

I wasn't intending to point that at you. There are a few people, whom I won't name, that are very against ABS because they believe they are able to control brake locking better than a computer while maintaining optimal traction; one even went so far as to try and "prove" how ABS caused him to wreck, and had he just been sliding out of control with his wheels locked, he'd have been just fine.

Lol. I have a love hate with that tech. On the one hand it lets you steer but on the other hand, if you are used to no ABS, you may expect to lose steering while being able to stop faster. Two very different styles of threshold driving. Not that anyone should get themselves into such situations to begin with.

 

[smackababy]

Lol. I have a love hate with that tech. On the one hand it lets you steer but on the other hand, if you are used to no ABS, you may expect to lose steering while being able to stop faster. Two very different styles of threshold driving. Not that anyone should get themselves into such situations to begin with.

I am certain there is proof that the only circumstances at which a non ABS car stops at a shorter distance than one with ABS is when the snow forms a wedge in front of the tire and very unlikely to happen.

I could understand not wanting ABS on a track and possibly not understanding how to react when it engages (I would wager most people's reaction is to immediately let off the break, rather than continue to apply pressure), but it is better in every way than non ABS.

 

[Pray To Jesus]

Lol. I have a love hate with that tech. On the one hand it lets you steer but on the other hand, if you are used to no ABS, you may expect to lose steering while being able to stop faster. Two very different styles of threshold driving. Not that anyone should get themselves into such situations to begin with.

:biggrin:

 

[Scarpozzi]

My favourite is watching guys in 4X4 pickup trucks fishtailing all over the place on icy roads.

This.

They don't understand that when you lock your hubs in 4WD, you're actually taking a chance on losing traction if traveling at higher rates of speed. You see this most often when people are in 4WD on highways... This is the one place that AWD is superior to even 4WD because of the advanced limited slip differentials they typically have....but alas, you still have the same braking technologies.

If you know how to effectively downshift in an AWD or 4WD, you can potentially stop in a shorter distance while maintaining control, but all it takes is having more than 1 tire break loose and without limited slip, you can be up the creek (or down) quickly.

 

[IronWing]

So how come basic physics is easy but fundamental physics is hard?

 

[Lean L]

:biggrin:

It's the second paragraph on Wiki with 3 cited sources...

I've never had ABS kick in while not in ice or snow so speaking from that limited experience.

W/e though, not changing the topic to ABS now.

 

[Pray To Jesus]

It's the second paragraph on Wiki with 3 cited sources...

I've never had ABS kick in while not in ice or snow so speaking from that limited experience.

W/e though, not changing the topic to ABS now.

Basic physics on friction is what formulas?

 

[BoomerD]

I thought the OP was in the SF bay area...


Anyway...I didn't study fizicks.

 

[SlitheryDee]

What goes up must come down.



That's physics, right? Don't see what that has to do with AWD. Everyone knows that cars run on alchemy. How else can the foul smelling stuff you put in the tank feed the horses under the hood?

 

[Lean L]

Basic physics on friction is what formulas?

Friction = Coefficient of friction x force where of course non locking brakes have a higher coefficient due to being static.

In a lab, yes this is true 100% of the time. I may be overthinking this or my mind is being stubborn but me thinks snow piled on top of ice changes the equation as you're piling on new snow when you push it.

 

[SP33Demon]

I hate making analogies but this is akin to saying 'I'm not getting any taller despite taking steroids.' Yes, steroids help you grow just like AWD helps you get around during the winter but it's not supposed to make you taller just like how AWD is not preventing you from slipping.

HGH (mostly associated with roiding b/c it lays the foundation) does make you taller by making the skull bigger. I know this from personal experience, a friend of mine used to inject and told me as much and you can tell that his head is stupidly disproportionate to the rest of his body. He said his feet also got bigger. It's also documented that Barry Bonds' hat size went from 7.5 to 9 from his HGH use. Not to be a spoilsport or crash your thread.

 

[Zenmervolt]

I am certain there is proof that the only circumstances at which a non ABS car stops at a shorter distance than one with ABS is when the snow forms a wedge in front of the tire and very unlikely to happen.

Your certainty is great. It's wrong though.

ABS shortens stopping distance only on dry and wet asphalt, and even then only by a small amount.

On slippery surfaces, ABS lengthens stopping distances considerably compared to fully locked wheels. On glare ice, the worst surface, stopping distance with ABS is double that of locked wheels. This is because there is so little grip that the wheels do not come back up to speed fast enough for ABS to re-apply the brakes very hard at all.

While you're right that the old "wedge of snow" theory is wrong, the fact remains that ABS makes stopping distances longer on the most adverse surfaces.

That said, it's ridiculous for people to prefer the shorter distance given the complete lack of control that fully locked wheels create. ABS is absolutely better because it allows the driver to maintain control and drivers who say otherwise are deluding themselves, at least with regard to the situations that are likely to occur on public roads.

ZV

 

[smackababy]

The highest amount of stopping distance I've read was 27%, and that was on lose gravel or loose snow, and was attributed to the wedge.

It also seems ABS relies on the other tires not locking, so on ice, it is possible to "fool" it because multiple wheels can lock at once.

But, I do agree, even with a longer stopping distance, being able to maneuver is infinitely better than just sliding to a stop in whichever direct your car feels like going.

 

[jagec]

Your certainty is great. It's wrong though.

ABS shortens stopping distance only on dry and wet asphalt, and even then only by a small amount.

On slippery surfaces, ABS lengthens stopping distances considerably compared to fully locked wheels. On glare ice, the worst surface, stopping distance with ABS is double that of locked wheels. This is because there is so little grip that the wheels do not come back up to speed fast enough for ABS to re-apply the brakes very hard at all.

I'll also add "gravel" and "washboard roads" to the list of surfaces where ABS significantly lengthens stopping distances.

I agree that for the vast majority of drivers on the vast majority of roads, ABS is safer than no ABS.

Anti-ABS drivers are welcome to install a momentary switch in-line with the ABS fuse if they want to disable ABS for certain situations. Motorcyclists who ride their bikes both on and off road do this routinely, as locking your rear tire off-road is a very standard practice.

 

[Lean L]

HGH (mostly associated with roiding b/c it lays the foundation) does make you taller by making the skull bigger. I know this from personal experience, a friend of mine used to inject and told me as much and you can tell that his head is stupidly disproportionate to the rest of his body. He said his feet also got bigger. It's also documented that Barry Bonds' hat size went from 7.5 to 9 from his HGH use. Not to be a spoilsport or crash your thread.

Ehh good piece of trivia to know.

 

[Ken g6]

But PhysX wasn't written in Basic.

 

[SKORPI0]

 

[Zenmervolt]

The highest amount of stopping distance I've read was 27%, and that was on lose gravel or loose snow, and was attributed to the wedge.

It also seems ABS relies on the other tires not locking, so on ice, it is possible to "fool" it because multiple wheels can lock at once.

But, I do agree, even with a longer stopping distance, being able to maneuver is infinitely better than just sliding to a stop in whichever direct your car feels like going.

Road & Track did an intensive comparison some time ago, which is where the ice distance reference comes from.

Basically, on wet asphalt and concrete, ABS shortened stopping distance by a moderate amount compared to fully locked wheels. On dry asphalt and concrete ABS shortened stopping distances slightly.

On surfaces like gravel, dirt, sand, etc., ABS lengthened stopping distances moderately.

On very slick surfaces like hard pack snow or glare ice, ABS lengthened stopping distances considerably (up to 2x on ice), but all testers agreed that the increased control was superior to having the wheels lock (especially since it did a great job of preventing spins).

On loose snow, the ABS performed between gravel and hard-packed snow.

They never saw any significant "wedge" buildup in their testing.

EDIT: It's important to note that we're talking about increased stopping distance compared to a locked wheel. Most of us never really get into that situation. For example, my Volvo's 60-0 braking distance was tested at 119 feet (dry pavement). I've never come close to that on the street because it's just not wise to drive right up on the edge of things like that. On a typical day I'll start slowing for a stop sign 300 to 400 feet away. In practical terms, most people will never notice even the doubled stopping distance on ice if they're paying proper attention to what's going on around them.

ZV