IS this a real anti-lock retrofit, or hype?

[Guest jjohart]

Hi, I was wondering if anyone understood this system fully, or better yet, had experience with it on any car. I'd like to know if it would help prevent lock up on icy roads, reduce braking distances, and be the next best thing to modern, computerized ABS? I tend to doubt it...

http://www.advancedbrakes.com/about.htm

[TimZ]

I'd like to know if it would help prevent lock up on icy roads' date=' reduce braking distances, and be the next best thing to modern, computerized ABS? I tend to doubt it...

http://www.advancedbrakes.com/about.htm[/quote']

 

Ummm... No, no, and no.

[Guest Anonymous]

I was given a set years ago,( this is not new) and put it on my autocross Z. It had the bling factor but that is it. I will make you a great deat on the set if you want them. Mark

[Guest Thurem]

Those guys are gonna end up getting sued for something....

[Guest Smooth Operator]

I would NOT put that on any car I drive.

[baddriver]

The best solution is to learn to brake properly and smoothly. A well-educated braking foot can maintain control of the car while also bringing it to a stop in the minimum possilble time. Proper braking by someone with a feel for the pedal will result in shorter, quicker stops than is possible even with anti-lock brakes. Anti-lock really only improves 'panic' braking and braking under adverse conditions. That good for most drivers, but not ideal for driving on the edge.

[Guest Cusp]

This sounds to me like a glorified equivelent of air in the lines. "excess presure is absorbed"? What are we, retards? I'm not sure how having a mushy pedal would make braking better under ANY circumstances.

[Guest ElvisTorino]

Anti-lock brakes stop much slower than non-ABS. The advantage to ABS is that in a panic stop you won't ruin your tires by skidding.

[TimZ]

Anti-lock brakes stop much slower than non-ABS. The advantage to ABS is that in a panic stop you won't ruin your tires by skidding.

 

Not to mention being able to control the vehicle. Small detail.

 

The stopping distance argument really only holds true on moderate- to loose-packed snow or gravel (or similar) surfaces. On these surfaces a locked wheel will build up a wedge of snow or gravel in front of the wheel, which helps the stopping distance.

 

It is VERY difficult to out-brake a modern ABS system (a REAL one, not the pretend thing referred to above) on pavement, wet or dry. Even if you can manage to do so, I'd be willing to bet that it would be on the order of one in 20 tries, with the ABS stops performing very consistently in the meantime.

[Guest ElvisTorino]

From the information I've seen, on dry paved surfaces, the ABS will take longer to stop, but you will have more tread life with the ABS. A panic stop on non-ABS vehicles stops the wheel in one spot causing a skid. The skid wears out the rubber in one spot thus ruining the tire.

 

Its not actually all that difficult to out brake (as in distance), but it is very difficult to out brake (as in performance, handling, and control) an ABS.

 

Multiple tests have confirmed that non-ABS equipped vehicles stop faster than ABS equipped vehicles. The ABS equipped vehicles were better able to stop in a controlled fashion. Also the ABS vehicles could stop faster every other road surface condition, other than dry pavement.

 

A true antilock brake system is leaps and bounds above any non-antilock brake system. The one on which the question was originally posed is farsical, however.

[TimZ]

Multiple tests have confirmed that non-ABS equipped vehicles stop faster than ABS equipped vehicles. The ABS equipped vehicles were better able to stop in a controlled fashion. Also the ABS vehicles could stop faster every other road surface condition, other than dry pavement.

 

That is pretty much exactly the opposite of what I have seen. However, this argument is getting a bit off topic - probably my fault. Here is a somwhat recent post that I found that had some interesting info about the pretend ABS thing:

 

http://www.hybridz.org/phpBB2/viewtopic.php?t=19913&highlight=

[Guest macks]

Think of it like this - your tyres give the most grip when they're just on the edge of locking up, not when they're locked solid. This means your car will stop in the shortest distance when the tyres are held on the edge of locking up. Yes, a locked tyre will flat spot, and that's bad, but tyre life would be the least of your worries if it means not hitting a tree/car/truck/wall. A properly set up ABS equipped car will hold the tyres at their point of maximum grip more consistently and sooner than any other method, and will hence outbrake everything, as well as retaining steering control.

 

The idea of threshold braking is to imitate this - to brake hard enough to be on the point where the tyres are about to lock. With practice, you can get pretty good at it - but never as consistent as a system that locks and unlocks the wheel 10 or more times a second, so in a panic-stop situation ABS is the way to go.

[Moridin]

You will never be able to out-brake an ABS equipped modern car with an equally non-ABS equipped vehicle. It's simple not possible, as the computer is far more precise and quick than any input from the driver. Now...if you change tire diameter and brakes, the ABS may not function properly. Maybe even to the point that longer stopping distances arise.

 

Oh...That Brakemaster thing seems like a bunch of B.S. We should sue him for false advertisement and split the money between our Z's.

[TimZ]

You will never be able to out-brake an ABS equipped modern car with an equally non-ABS equipped vehicle.

 

Well, 'never' is a strong word...

 

As I mentioned before, there are situations where ABS can increase stopping distance - most notably on deformable surfaces (packed snow, gravel, etc). In this case the ABS prevents the formation of the wedge of crap that would normally build up in front of the tire, which would have added additional stopping force.

 

Another instance would be on "Split mu" surfaces (i.e., right side of the car is on dry pavement, left side is on ice). Braking on such a surface will cause a very significant pull towards the pavement side. The abs system will make a calculated tradeoff here to try to regain some amount of stability - namely by reducing the right-left imbalance by reducing the brake pressure to the pavement side. This will increase the stopping distance, but you have a much better chance of staying on the road and not spinning out. All modern ABS systems do this tradeoff to some extent, but the balance between stability and stopping distance will vary from manufacturer to manufacturer.

 

However, in my experience dry or wet pavement is not one of the places where it is easy to out-brake an ABS system.

[johnc]

On a race track (admittedly a pretty artificial environment) a good driver can turn a faster lap with the ABS off in almost all cars (the Z06 Corvette is one exception that I know of.) ABS induces understeer in a turn and its often hard to feel exactly when the ABS is going to kick in. ABS also pretty much kills brake pedal feel. In the rest of the world you're not going to beat an ABS equipped vehicle especially if you have the presence of mind to try and steer away from the wreck as your foot is hard on the brakes.

 

ABS systems do some funky things once in a while. At a number of autocrosses I've seen the ABS systems on late mdoel Camaros go into something called "Ice Mode", which basically means you have no brakes until you settle the car and let it coast for a second with your foot off the brakes. This usually happens during hard left, right, left, right transitions under braking (like a decreasing slalom). Steve Eugina's Camaro rolled off the course at 20 mph into a small ditch with him yelling the whole way, "I got no brakes!" When the car finally stopped, he had brakes. We gave him crap about it for months afterwards.

[Moridin]

You will never be able to out-brake an ABS equipped modern car with an equally non-ABS equipped vehicle.

 

Well' date=' 'never' is a strong word...

 

As I mentioned before, there are situations where ABS can increase stopping distance - most notably on deformable surfaces (packed snow, gravel, etc). In this case the ABS prevents the formation of the wedge of crap that would normally build up in front of the tire, which would have added additional stopping force.

 

Another instance would be on "Split mu" surfaces (i.e., right side of the car is on dry pavement, left side is on ice). Braking on such a surface will cause a [b']very[/b] significant pull towards the pavement side. The abs system will make a calculated tradeoff here to try to regain some amount of stability - namely by reducing the right-left imbalance by reducing the brake pressure to the pavement side. This will increase the stopping distance, but you have a much better chance of staying on the road and not spinning out. All modern ABS systems do this tradeoff to some extent, but the balance between stability and stopping distance will vary from manufacturer to manufacturer.

 

However, in my experience dry or wet pavement is not one of the places where it is easy to out-brake an ABS system.

 

Sorry, I had to use never, otherwise you guys wouldn't have responded what you did (I really like playing devil's advocate)

 

It all depends on the car you are driving though. I've heard a lot cars are only two-channel ABS systems, where some are a true four-channel (each tire having its own sensor blah, blah, blah...) Anywho, it has been my understanding that a properly programmed 4-channel system will almost always outbrake a car without it, in most situations. I can see 2-channel systems having problems on split mu or dual frictional surfaces, but a 4 channel shouldn't have a problem (Then again, it all depends on how it was programmed).

 

I'm not sure how it affects trail braking though. If it doesn't work properly under those situations, I could see why the car would have a hard time turning quicker lap times than a non-ABS vehicle. This is only a guess here, but I wonder what an E46 M3 would do. Run some laps with the ABS on, then pull the fuse (and hope nothing goes haywire) and see what happens then. A Supra would be another good car, as its ABS system is supposed to be superb (that's based on an interview I heard about with Mario Andretti driving the Supra).

 

John, you have more funny stories than I keep track of. I could just imagine seeing a guy yelling "I have no brakes," and then rolling into a ditch. Too bad you don't have that on film (or do you?).

[TimZ]

On a race track (admittedly a pretty artificial environment) a good driver can turn a faster lap with the ABS off in almost all cars (the Z06 Corvette is one exception that I know of.) ABS induces understeer in a turn and its often hard to feel exactly when the ABS is going to kick in. ABS also pretty much kills brake pedal feel. In the rest of the world you're not going to beat an ABS equipped vehicle especially if you have the presence of mind to try and steer away from the wreck as your foot is hard on the brakes.

 

Agreed. Again, this is most likely a conscious calibration tradeoff between stopping performance and stability. Inducing understeer is generally considered the more conservative approach for the average driver. The Corvete most likely had different priorities.

 

ABS systems do some funky things once in a while. At a number of autocrosses I've seen the ABS systems on late mdoel Camaros go into something called "Ice Mode", which basically means you have no brakes until you settle the car and let it coast for a second with your foot off the brakes. This usually happens during hard left, right, left, right transitions under braking (like a decreasing slalom). Steve Eugina's Camaro rolled off the course at 20 mph into a small ditch with him yelling the whole way, "I got no brakes!" When the car finally stopped, he had brakes. We gave him crap about it for months afterwards.

 

If i had to guess, this probably gets invoked by repeatedly unloading the tires during the slalom. This most likely sends the unloaded tire into much deeper slip than would usually be expected. When the ABS controller sees this more than once or twice, it probably assumes that it's on patchy ice and alters its behavior accordingly. Again this is probably a tradeoff that was made for maintaining stability on icy surfaces.

[TimZ]

I can see 2-channel systems having problems on split mu or dual frictional surfaces' date=' but a 4 channel shouldn't have a problem (Then again, it all depends on how it was programmed).

[/quote']

 

I was referring to 4-channel abs systems - when you get on split mu, there is only so much that physics will allow - you either have to force the driver to do some very aggressive steering to keep the car straight (or let him spin out if he doesn't know what to do), or you stabilize the car and let the stopping distance increase.

 

BTW, when you brake hard on a split mu surface, the pull is immediate, very hard, and almost always completely unexpected. This can be difficult to handle even when you know it's coming.

[Guest ElvisTorino]

Some ABS/TRAC systems have a yaw sensor. This sensor allows the abs to "feel" how the car is moving. If the car seems to be moving in a pattern similar to, say, ice the ABS will act according to it's programming.