Contour Enthusiasts Group Archives Forums Modifications Brakes improving emergency stop distance

All cars without ABS have the mechanical proportioning valve, and all cars with ABS have EBD, EDS, or whatever you want to call it. I do remember reading a recall on the thing for cars without ABS. My 6000 has Bosch ABS, and the 6000 and the Mystique have about the same braking performance I'd say. They both stop in a short distance, and they both have great ABS systems.

The bosch ABS module/program is custom tailored by bosch engineers for the specific car. It is optimized for the OEM parts. Any change with any parts (tires, wheels, pads) and you can throw the program off, if only by a little bit.

Many of these changes simply do not allow the easy steering while brakeing feature of ABS... in other words, you may expirence some short bursts of lockup... or may never be able to extract all the stoping power of the new tires.

Originally posted by Cool Blue Mystique:

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All cars without ABS have the mechanical proportioning valve, and all cars with ABS have EBD, EDS, or whatever you want to call it. I do remember reading a recall on the thing for cars without ABS. My 6000 has Bosch ABS, and the 6000 and the Mystique have about the same braking performance I'd say. They both stop in a short distance, and they both have great ABS systems.

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Not true. I have had a number of cars with ABS and mechanical proportioning valves. In addition, not all mechanical proportioning valves are alike. Some are fixed (Like my 86 pontiac 6000, born about the time you were) and some are load adjustable and connect to a rear suspension piece to compensate for loaded and unloaded conditions. My 94 Sable was like this, 4 channel ABS and a mechanical valve. Most "modern" (Modern being less than 50 years old) pickups without ABS have a variable prop. valve. Though nowadays, "rear ABS only" compensates for this. My company has a couple of Ford Econolines like this (About 2000).

Get the stickiest tires you can find, and learn threshold braking. ABS is a substitute for true threshold braking, and very very rarely is a good substitute for it. A good driver can typicaly stop faster without the "aid" of ABS if he (or she) utilizes the technique of threshold braking.

The key behind it, is the fact that tires offer the most grip when they in a state of some slip while still rolling, usually it is around 7% slip, but really depends on the tire. ABS systems kick in when ANY slip is detected (the better systems do try to accomodate for the little bit of slip) where threshold braking is all about holding the car right on that razor's edge between still kinda rolling and sliding. ABS sytems, by there very nature, kick above and below that line very rapidly, not taking full advantage of it; with the faster, better systems able to take better advantage of it though.

Bottom line, most people can't do it, and I don't think there is anybody that can do it every single time (heck, Mr. Schumacher even locks 'em up on occasion) so we have ABS.

As far as swapping components between systems, etc. well, for the most part I would be amazed if they work at all, but kepe in mind, that you have absolutely no way of knowing if you have actually improved your system, or made it worse, at least not without extensive testing, on a closed track, and with very very expensive test equipment, that I'm not sure many of us have ever even seen, let alone have access to.

Not all ABS systems include EBD (electronic brake distribution). EBD is an enhancement of ABS. If I remember correctly, Volvo added EBD in 1999. I remember a customer who did not like the noise his new Volvo sometimes made on hard breaking that his two year older Volvo did not make.

My 98 E0 SVT does not have EBD. If EBD was added to later Contiques, or even only SVT's, I'll have to take your word for it. Mine does have rear pressure reducing valves (although the part number is different from non ABS cars). I don't remember seeing anything about EBD in Ford products until the launch of the Lincoln LS.

EBD is a good thing in that it can take several factors in determining proper rear braking force so that under some conditions it can use the rear brakes much more agressively. Think of it as a continusly variable proportioning valve.

My experience with ABS is that as long as the tire size remains close to the factory size the system still works great. The Lincoln LS owner that complained of ABS problems with 22" wheels and much larger diameter tires did have a self inflicted problem. Tires that are not as sticky seem to make the ABS come on more easily while tires that are very sticky seem to make the ABS harder to invoke (which is a good thing). Think of ABS as your emergency friend. When it does come on, it just might save your life. It is better still to try to stay out of those life threatening situations. I see no benefit in trying to make the ABS come on any easier.

I really don't know all the answers here, but this is my $.02 contribution.

I meant all ConTiques without ABS have it.

I would never drive in a car without ABS, I judt dont feel safe in them. Try driving 45mph down the street when it'c oevered in glare ice, and having a stoplight turn red on you. I've had that happen to me in my Mystique, my 6000, and my mom's BMW, all of which obviously have ABS, and I stopped perfectly while I remember one time an Escort next to me went sliding into the drivers door of a minivan. Or driving 65 down a gravel road at night, and having a deer jump infront of you, I'm glad I have ABS. One of the best safety features they ever invented.

I wonder if you have ever driven a Car without ABS. How about all drum brakes and no power?? Ever driven a car with no power steering, no power brakes, no A/C, no power windows, no disk brakes, no HP, No fuel injection, no alternator, no radial tires, no airbags, no catalytic converter, no PCV valve, no automatic Choke, no synchronizers on the tranny ? You probably haven't and will never know the pure mechanical connection one can have with a car. By the time you are independent of your parents, cars will be totally fly-by-wire and the driver will have no direct connection to the machinery he/she is operating.

ABS will increase braking distance in loose snow. Instead of snow building up in front of the wheel and helping you stop, the wheels keep turning on top of the snow and have less traction. Sand is similar, gravel is similar. ABS is better in most other circumstances. Cheap ABS has drawbacks too. My Sable would swerve badly when one side of the car had bad traction and one side good. IE: hard braking when right wheels were near shoulder (sand/debris) and left on good traction pavement. It nearly caused me to have an accident.
On hard braking in a sharp turn, the inside rear wheel would lift, engaging the ABS, and not allowing as fast a braking rate. The computer doesn't always do the right thing. The ABS for brakes is similar to ATX for transmissions. In most cases it shifts/brakes the way you want, but in some conditions, it chooses the wrong action. IMHO.

In reply to:

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I would never drive in a car without ABS, I judt dont feel safe in them. Try driving 45mph down the street when it'c oevered in glare ice, and having a stoplight turn red on you.

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You need to learn how to drive...like Rara said...threshold braking.

I once saw on TV a "professional" driver driving a car with ABS disabled, and a regular person driving the same car with ABS. Using threshold braking, in any condition the car without ABS stopped faster and maintained more control over the car. Quite frankly...the whole "mash the pedal" mentality most people and car manufacturers are developing scares me...

ABS is really only a way for folks that can't get the most out of thier brake systems top get more out of it in the bad situations.

EBD is pretty new in the braking world, and I'm pretty sure that no contique (Cougar too) ever got EBD. And if they did, its not "real" EBD, but just an electronic prop valve, rather than a real distribution system (you see these on vehicles w/ IVD)

Split Mu braking also can be a challenge (when the two sides of the car have dramatically different levels of grip, like described above) Manufacturers spend a great deal of time these days developing a system that doesn't respond badly to split Mu (like was described above)

Don't get me started on panic assist braking . . .