aftermarket abs?

[Guest Anonymous]

are there any companies that make true abs for the aftermarket? i mean i could pick up a m.c. off a car with abs, and get the wheel sensors...what else is needed?

 

eric

[DatsunBoy77]

you would probably need some kind of electronic controller for the sensor. But as far as i know, there is no aftermarket ABS kits. But then again i don't know anything.

[Guest Anonymous]

I would be interested in aftermarket abs. Mine have been covered by several inches of flab.

[SleeperZ]

I'd bet $ the abs controllers are stand-alone, just for safety's sake. Just find a car that has adaptable wheel sensors, and get the controller and the ECU - you should e off and running once you figure out the plumbing and wiring. I think you could use any MC (they look the same as any ordinary one), just by looking at the ABS system in my Subaru...

[Wagz]

I don't know of a true aftermarket ABS. Check out the information on the "Anti-skid Braking System" this guy is advertising. I don't have any personal experience, but it 'might' be worth a look...

 

http://www.zspecialties.com/hotdeal.htm (scroll to bottom of page)

[Guest AlsoRanFPrepared]

You will need the abs pump too. THis pump delivers pressure to the system to accomodate the cycling on and off of the brakes as the system runs. You will also need the computer to control the sysem.

 

As for the anti skid system I would avoid it. DO a search for yourself and decide. Like everything else I have to say show me the data. Not endorsements but actual data.

 

THis was interesting...

 

# O. Brake Guard Products, Inc.

#

# • On January 15, 1998, the FTC issued an order concluding that Brake Guard Products, Inc., did not have competent and reliable scientific data to support its advertising claims.

# • The order requires Brake Guard to discontinue advertisements claiming that its add-on braking system performed as effectively as factory-installed antilock braking systems.

# • Brake Guard may not use the term "ABS" in marketing its product.

# • Brake Guard may not misrepresent that installation of its product will make a vehicle safer to operate than a vehicle not equipped with the system.

# • Brake Guard may not misrepresent the product’s compliance with government standards, the availability of insurance discounts resulting from installation of the brakes, or their performance and safety benefits.

# • Brake Guard may not use any endorsement of its product that represents the typical experience of a person who uses the product unless such representation is true and the company discloses the generally expected results for users of the product or the limited applicability of the endorser’s experience to the generally expected results and that consumers may not experience similar results.

# • Brake Guard must notify by mail all purchasers of the Brake Guard Safety System, Advanced Braking System, or Brake Guard ABS since January 1, 1990, of the FTC findings. The company must maintain records of such correspondence for five years after the last date of dissemination.

[Guest Aaron]

I don't know for sure, but it is my understanding that the ABS systems in some of the low end american cars (Cavalier/Sunbird, Escort, Tempo, etc.) from the early 90's were simply systems that cycle the hydrolic pressure once the brake pedal is pushed so far.

[TimZ]

I don't know for sure, but it is my understanding that the ABS systems in some of the low end american cars (Cavalier/Sunbird, Escort, Tempo, etc.) from the early 90's were simply systems that cycle the hydrolic pressure once the brake pedal is pushed so far.

 

No, AlsoRan is correct - a hydraulic pump is required to maintain the brake pressure. During an ABS cycle, braking pressure is relieved by releasing fluid from the offending caliper's circuit and recycling it back to the low pressure side of the system. If there were no pump, then the pedal would drop to the floor in about a second or two. Most modern systems have the pump integrated into the hydraulic control block.

 

You will probably not find an aftermarket ABS system for sale by any sane company -the liability is WAY too high. Think about it - if done incorrectly, this could easily cause complete brake system failure. Doing the ABS control part is relatively simple. The part that the ABS suppliers generally spend the bulk of their time on is making sure that the system cannot fail in an unsafe manner. Generally, some amount of fine tuning is required to adapt the system to a specific car's dynamic and hydraulic configuration.

 

That said, if all you want is ABS (forget about traction control or yaw control systems, btw), you could probably retrofit an ABS system from a similar (weight, weight distribution, RWD, etc) modern vehicle, but it would take a great amount of expertise and access some engineering info about the unit. ABS systems are reasonably adaptable, and you probably could get one to work acceptably. The trick would be to reproduce the ENTIRE electrical and hydraulic environment from the donor car, as seen by the ABS unit. Due to the failsafe meaures I mentioned above, most ABS systems will shut themselves down if they find stuff missing that they need. This includes serial communications bus messages in many cases. Not fun.

 

Oh - and the hydraulic system would need to be laid out in the same manner - most modern vehicles split their two hydraulic circuits diagonally (i.e, front right and rear left are on the same circuit), whereas our cars are front/rear split. This would necessitate replumbing the entire hydraulic system. And you would probably want to do a rear disk conversion. Much easier to find 4 wheel disk ABS systems.

 

I also agree on the BrakeGuard junk. Stay Away. I guess it won't really hurt anything, but it doesn't really do anything, either. These are basically a pair of small high presssure accumulators (hydraulic equivalent of a capacitor) that you put on each circuit of your braking system. I had heard of some informal tests done by a major ABS supplier on these, just to see if there was anything to their claims. As I recall, the only noticeable effect was longer pedal travel during braking, since the BrakeGuard things added some compliant volume to the system. The braking distance was not reduced, and wheel lock was not prevented.

[Guest Anonymous]

well, actually, i would want to have traction control, but the yaw sensors dont matter to me.

 

are the abs computers usually separate from the ecu? cuz if so, then i could just find a good big brake setup with abs and mod it to fit the Z?!

 

eric

[TimZ]

well' date=' actually, i would want to have traction control, but the yaw sensors dont matter to me.

 

are the abs computers usually separate from the ecu? cuz if so, then i could just find a good big brake setup with abs and mod it to fit the Z?!

 

eric[/quote']

 

If you mean "ecu" to be the engine controller, then yes the ABS controller is always separate. I know of no systems that have the ABS controller integrated with the engine controller. The ABS controller is usually integrated with the hydraulic controller, or in a separate module.

 

So, as you guessed, your best bet would be to find a good brake setup with ABS and retrofit the entire thing to the Z. As I mentioned before, the donor car would also have to be of similar weight, weight distribution, be RWD, and you would have to be able to reproduce all or most of the electrical and hydraulic environment from the donor car, including any communications bus messages that it might expect to see. Not a trivial task, but it could be done.

 

Traction control comes in a few flavors: brakes-only, engine only, and brakes and engine. Most modern systems do both engine and brake control. Doing engine intervention requires communication between the ABS/TC module and the engine controller - basically, the ABS controller tells the engine controller to reduce the torque to the drive wheels by a specific amount, and the engine needs to respond to this. I know of no aftermarket engine controllers that have the capability to communicate and respond in this fashion.

 

So, the brakes-only system is pretty much the only type that you would have a prayer of getting to work. These systems have limited capability - they are only effective up to around 30mph. They also require a fair amount of tuning to get adequate response. Further, there are usually algorithms built in to keep from frying the rear brakes if for some reason the system is kept in operation for an extended amount of time (say if you are stuck in deep snow). These algorithms are very specifically tuned to the expected power available from the powertrain, and the specific brake system on the car. If you considerably raised the horsepower level over that of the donor car (very likely in most of our cases), and/or had different rear brakes (also very likely), you would probably either run into the situation of risking frying your brakes, or the system would be shutting itself down whenever you used it, depending on the nature of the mismatch.

 

Also, TC systems pretty much always require that an open diff be used. Limited slip diffs will couple the brake torque from one side the other, and not in a predictable fashion, making it impossible to properly manage the brake pressure to the wheel that is spinning.