Dodge Viper crashes into stopped traffic

[2M6]

Again you bring up other siuations where ABS is beneficial.......I'm not arguing those points whatsoever.

When a car is spinning, it's rotating perpendicular to the rotation of the tires (or close to it). This means the force the tires exert on the car are opposite to the direction of spin, and have very little to do with whether the tires are rotating or not.

This statement makes little sense. The rotation of a spin is perpendicular to the rotation of each of the tires exactly twice during a 360* rotation. At those two moments in time (and those closely preceeding and following) you are correct to say that the force of the tires (rotating or stationary) have little effect. However for the remainder of the rotation (of the spin) the tires will influence the attitude of the vehicle if they are rotating.


And even if you don't want to agree it has no affect on the fact. When the rotating tires of an ABS-equipped vehicle approach the slip angle during a spin they WILL alter the overall direction of the vehicle. I'm talking about a high grip surface here.

Example: Have you ever seen a driver lose control in one direction and then suddenly spin even more violently in the opposite direction? That's what happens when rotating tires gain a bit of tracion even for a moment. I don't have time to spend looking for videos to visually show you what I'm talking about but believe me there are plenty.

[UndrgroundRider]

Originally posted by 2M6
Again you bring up other siuations where ABS is beneficial.......I'm not arguing those points whatsoever.

You're arguing that ABS is not good for the track. Which would encompass all of the situations I've brought up.

Originally posted by 2M6
This statement makes little sense. The rotation of a spin is perpendicular to the rotation of each of the tires exactly twice during a 360* rotation. At those two moments in time (and those closely preceeding and following) you are correct to say that the force of the tires (rotating or stationary) have little effect. However for the remainder of the rotation (of the spin) the tires will influence the attitude of the vehicle if they are rotating.

That's because you're confusing direction of travel with rotational direction. The car may be sliding in a certain direction, but it will still be spinning about its centre. The tires will both decelerate the car from its overall vector, and from its rotational vector.

Originally posted by 2M6
And even if you don't want to agree it has no affect on the fact. When the rotating tires of an ABS-equipped vehicle approach the slip angle during a spin they WILL alter the overall direction of the vehicle. I'm talking about a high grip surface here.

That's twice now that you've misused the term slip angle. I fear you have no idea what it really means, and are just regurgitating some terms you've overhead somewhere. It has no application whatsoever when a vehicle is completing more than a 360 degree spin.

And to reiterate, no, they will not alter the direction of the vehicle. If what you said is true, it would be impossible to spin more than once unless your tires were locked... Sorry, but I can't swallow that.

Originally posted by 2M6
Example: Have you ever seen a driver lose control in one direction and then suddenly spin even more violently in the opposite direction? That's what happens when rotating tires gain a bit of tracion even for a moment. I don't have time to spend looking for videos to visually show you what I'm talking about but believe me there are plenty.

We're not talking about fish tailing here, and I had a guess this was what you were basing your opinions off of all along.

This doesn't happen in a full spin, this only happens when you still have traction in your front tires. It also requires that the driver over corrects a slide (which is the real reason for the violent snapping).

It might be the reason a spin started, but it wouldn't happen in the middle of one. Also, ABS (or no ABS) would have nothing to do with this situation. In a high speed turn, if you're on the edge of loosing losing it, the VERY VERY LAST thing you want to do is brake or even lift the throttle. That will spin you guaranteed 100%. So if you're not on the brakes, then the question of ABS never comes into play.

[robcortez1787]

Man that was nasty.

Did they rebuild it?

[crapstixs]

the funny thing is you can actually stop faster without abs with proper braking. its called threashhold braking. abs systems will apply and release 11 time per second to pervent melting of the tires and keep directional controll. the abs modual uses the wheel speed sensors and will apply the abs when there is a impendind wheel lock up. so that mean the computer is one step ahead of you, somtimes not good on the track. abs was not desined for the race track it was desined for when a kid jumps out infront of you on the street. but it dose not mean that it cant be benifical in certin parts of the race track.

[2M6]

Originally posted by UndrgroundRider



That's because you're confusing direction of travel with rotational direction. The car may be sliding in a certain direction, but it will still be spinning about its centre. The tires will both decelerate the car from its overall vector, and from its rotational vector.

Yes but when the tires "line up" with the direction of the slide (twice, when pointing forwards and backwards) the tires will have an influence on overall direction.

That's twice now that you've misused the term slip angle. I fear you have no idea what it really means, and are just regurgitating some terms you've overhead somewhere. It has no application whatsoever when a vehicle is completing more than a 360 degree spin.

Correct, slide angle would be a better fit for my explanation. Incorrect that slip angles have no application whatsoever. The contact patch will still twist relative to the direction of the wheel and have an influence.

And to reiterate, no, they will not alter the direction of the vehicle. If what you said is true, it would be impossible to spin more than once unless your tires were locked... Sorry, but I can't swallow that.

I'm not saying that the rotating tires of an ABS-equipped vehicle will magically end a spin merely that they will have an influence on the overall direction of travel for the spinning vehicle.

We're not talking about fish tailing here, and I had a guess this was what you were basing your opinions off of all along.

This doesn't happen in a full spin, this only happens when you still have traction in your front tires. It also requires that the driver over corrects a slide (which is the real reason for the violent snapping).

It might be the reason a spin started, but it wouldn't happen in the middle of one. Also, ABS (or no ABS) would have nothing to do with this situation. In a high speed turn, if you're on the edge of loosing losing it, the VERY VERY LAST thing you want to do is brake or even lift the throttle. That will spin you guaranteed 100%. So if you're not on the brakes, then the question of ABS never comes into play.

I was using that as an example of the tires approaching a slip angle near zero. The closer the slip angle gets to zero the more impact it has on altering the direction of the vehicle.

Let's take a simple state of understeer. If you introduce more steering angle the problem remains and the tires have little effect on direction. Now remove some lock and as the angle of the tires approach the direction of vehicle travel they regain traction and you will feel them "bite".

Now do this with the tires locked. When you dial the lock out there is no change in their influence because they are not rotating.

I know you can understand this lesson, if not then I don't think I'm ever going to get through to you.

[UndrgroundRider]

Originally posted by 2M6


Yes but when the tires "line up" with the direction of the slide (twice, when pointing forwards and backwards) the tires will have an influence on overall direction.

Wait, you've changed from "violent change in direction" to "influence on overall direction." I don't disagree with what you're saying. I disagree on the points that this "influence on overall direction" makes ABS inferior on the track, and that it will cause a "violent change of direction."

Originally posted by 2M6
Correct, slide angle would be a better fit for my explanation. Incorrect that slip angles have no application whatsoever. The contact patch will still twist relative to the direction of the wheel and have an influence.

Wrong. Contact patches don't twist, tread elements do. Also, the significance of a slip angle when you're spinning is absolutely nothing. Slip angles are useful only when you know the tires have traction, not when you are spinning (and do not have traction). Feel free to correct me by providing an example to the contrary.

Originally posted by 2M6
I'm not saying that the rotating tires of an ABS-equipped vehicle will magically end a spin merely that they will have an influence on the overall direction of travel for the spinning vehicle.

But that's not what you said. You said the car was going to violently change direction if the wheels weren't locked. You later explained that it would work just like a fishtail.

I think you now see the light of day, and realize the physics don't support that conclusion.

Originally posted by 2M6
I was using that as an example of the tires approaching a slip angle near zero. The closer the slip angle gets to zero the more impact it has on altering the direction of the vehicle.

You're confused about the physics of this situation as well. What's causing the rapid change in direction is steering from the front wheels. It has nothing to do with approaching a zero slip angle. You approach a zero slip angle everytime you straighten the car after a corner.

What's happening in a fishtail is something completely different. The rear wheels have broken traction, and have stepped out of alignment with the front wheels. When the driver counter-steers to correct, the car pivots at the centre of the front axle. This causes a change in direction, which may cause a small movement in the front of the car, but that translates to a large movement in the rear, because the car is pivoting on the front axle. This is similar to how a lever works.

Originally posted by 2M6
Let's take a simple state of understeer. If you introduce more steering angle the problem remains and the tires have little effect on direction. Now remove some lock and as the angle of the tires approach the direction of vehicle travel they regain traction and you will feel them "bite".

Now do this with the tires locked. When you dial the lock out there is no change in their influence because they are not rotating.

Yes, a tire needs to be rolling through a contact patch to provider cornering force (which is actually when it is useful to know about slip angles). But this doesn't help explain your theory of "violent changes in direction" at all. It just says a locked tire provides no cornering force, and an unlocked tire does. Nobody is arguing that. What we're talking about is the effect of that.

Originally posted by 2M6
I know you can understand this lesson, if not then I don't think I'm ever going to get through to you.

I don't know what driving school they taught you this lesson at, but you should get your money back.

[2M6]

Originally posted by UndrgroundRider
[B]

Wait, you've changed from "violent change in direction" to "influence on overall direction." I don't disagree with what you're saying. I disagree on the points that this "influence on overall direction" makes ABS inferior on the track, and that it will cause a "violent change of direction."

It makes it inferior to me for this exact reason. I am physically capable of modulating a brake pedal to control my speed and position when entering a corner. I don't require ABS to dictate my brake application. I'm sorry you need this electronic nanny to do the work for you. Because I don't require help ABS is not beneficial to me on the track.

Wrong. Contact patches don't twist, tread elements do. Also, the significance of a slip angle when you're spinning is absolutely nothing. Slip angles are useful only when you know the tires have traction, not when you are spinning (and do not have traction). Feel free to correct me by providing an example to the contrary.

Actually the definition of slip angle is "the angular difference between the direction the tyre contact patch with the road is pointing and the direction of the wheel."

But that's not what you said. You said the car was going to violently change direction if the wheels weren't locked. You later explained that it would work just like a fishtail.

It's the same principal. As the angle of the tires line up with the angle of the slide they will "bite" and change the direction.

Yes, a tire needs to be rolling through a contact patch to provide cornering force (which is actually when it is useful to know about slip angles). But this doesn't help explain your theory of "violent changes in direction" at all. It just says a locked tire provides no cornering force, and an unlocked tire does. Nobody is arguing that. What we're talking about is the effect of that.

It perfectly explains it if you understand what you just typed.


I can see we are never going to be in agreement on this subject so I will not waste any more of my life trying to convince you otherwise.

[UndrgroundRider]

Originally posted by 2M6


It makes it inferior to me for this exact reason. I am physically capable of modulating a brake pedal to control my speed and position when entering a corner. I don't require ABS to dictate my brake application. I'm sorry you need this electronic nanny to do the work for you. Because I don't require help ABS is not beneficial to me on the track.

ABS brakes faster than you. Period. As I explained before that makes an ABS vehicle faster on the track. It can brake later, and trail more brake into the turn. And judging from your lack of knowledge and the videos you posted in your other threads, you couldn't out brake an 18 wheeler.

Originally posted by 2M6
Actually the definition of slip angle is "the angular difference between the direction the tyre contact patch with the road is pointing and the direction of the wheel."

Wrong. Slip angle is the angular difference between a wheel's pointed direction and its actual direction of travel. The tread elements in the centre of the tire shift due the car's momentum and the friction of the ground forcing the car to turn. The contact patch always matches up with the wheel.

Diagram:

Originally posted by 2M6
It's the same principal. As the angle of the tires line up with the angle of the slide they will "bite" and change the direction.

LOL. The only thing that happens when the tires "bite" is the car stops spinning. It doesn't automatically spin the other direction. Not only is that ridiculous, but it defies the laws of physics. If a car is spinning one direction, where does the energy come from to spin it back the other direction?

I've provided videos and logical explanations. All you have done is reiterated your crackpot theory.

Originally posted by 2M6
It perfectly explains it if you understand what you just typed.

I can see we are never going to be in agreement on this subject so I will not waste any more of my life trying to convince you otherwise.

Fair enough, I feel the same. By the way, I've raced kart my whole life, have my SCCA, been through half a dozen race schools, have a few dozen events under my belt and worked as a test driver for a number of years. I've probably spun on more courses than you've ever been on.

[GOnSHO]

No no no, my e-cock and intelligence is bigger and more profound..

i cant believe i just read all that crap.