afx spindle +abs ...rear end ideas ?

[gEtyOpAPiOn]

well i have an abs module already installed in my 69 camaro i now have the afx spindles ....anyone has any ideas on how to use a reluctor speed sensor for the rear ? i have a 3 channel abs ...any help would be great ... thanks

[Randy67]

Alot of the OEM's use a reluctor ring between the ring gear and the differential carrier. The sensor is usually on top of the housing. Maybe you could do something like this. Or you maybe could adapt a smaller reluctor ring to the yoke and have a sensor attached to the diff housing. just a couple ideas.

[Larry Callahan]

I have deleted a few posts in this thread. A statement was made regarding a product that was not authorized by the company making it.

[silver69camaro]

Rick,
I'm very curious how you are going to make the ABS work on your Camaro.

We get calls from people all the time about wanting to put factory ABS on their "insert car here" with our C5 front suspension.

Keep in mind that auto manufacturers have to spend millions in R&D to get an ABS system to work PROPERLY, meaning it's more effective than not having it at all. THIS IS NOT AN EASY TASK. I don't know what system you are using, but if you are using a factory module, your vehicle will not have the same COG location, weight bias, tire sizes, scrub radius, and every other parameter necessary to make it work correctly.

I probably sound like a jerk from reading this post, but I sure don't mean to. I'm not trying to say you can't do it!

[EFI69Cam]

Rick,
I'm very curious how you are going to make the ABS work on your Camaro.

We get calls from people all the time about wanting to put factory ABS on their "insert car here" with our C5 front suspension.

Keep in mind that auto manufacturers have to spend millions in R&D to get an ABS system to work PROPERLY, meaning it's more effective than not having it at all. THIS IS NOT AN EASY TASK. I don't know what system you are using, but if you are using a factory module, your vehicle will not have the same COG location, weight bias, tire sizes, scrub radius, and every other parameter necessary to make it work correctly.

I probably sound like a jerk from reading this post, but I sure don't mean to. I'm not trying to say you can't do it!

We addressed this in the deleted thread. It is my believe that the 4th gen Camaro is close enough in COG location etc to the 1st gen that the ABS will function properly.
If the system were as sensitive to these factors as you and others have made it out to be, they would not work very will with upgraded brakes, loaded trunks or wider than stock tires on the original vehicle.
There are guys bolting 275 front tires, huge 14" rotors and 6 piston calipers on their C5s and 4th gens all the time, and not once have I heard of a problem.
Sit back and approach the problem from a higher level, I think you're losing the forest for the trees.

[chicane67]

We addressed this in the deleted thread. It is my believe that the 4th gen Camaro is close enough in COG location etc to the 1st gen that the ABS will function properly.
If the system were as sensitive to these factors as you and others have made it out to be, they would not work very will with upgraded brakes, loaded trunks or wider than stock tires on the original vehicle.
There are guys bolting 275 front tires, huge 14" rotors and 6 piston calipers on their C5s and 4th gens all the time, and not once have I heard of a problem.
Sit back and approach the problem from a higher level, I think you're losing the forest for the trees.

A non ATS opinion

I agree. Unless the system is utilizing the active handeling aspect of the 8.x system, the COG, weight bias, tire size and scrib have very little to do with the operation of the ABS aspect alone. That system would require a yaw rate sensor, steering angle sensor and the accelerometer for those inputs to be a valid concern.

And as for the sensors, they are different. They work on an entirely different quotient...... although they still give a near the same end product and the principal of operation is similar, but the resolution is different. One works on the magnitude of voltage in the pulse train and the other works on the pulse width in the pulse train. This was due to saturation effects of voltage at high RPMs (vehicle speed capability of the new C5/6). So is there a difference ?? Well, yes there sure is.

I am sure the self proclaimed ABS experts around here might not agree, but do your homework on the 8.x system (which came from the precursor 5.3 cpu) and you might just learn something.

[EFI69Cam]

A non ATS opinion

I agree. Unless the system is utilizing the active handeling aspect of the 8.x system, the COG, weight bias, tire size and scrib have very little to do with the operation of the ABS aspect alone. That system would require a yaw rate sensor, steering angle sensor and the accelerometer for those inputs to be a valid concern.

And as for the sensors, they are different. They work on an entirely different quotient...... although they still give a near the same end product and the principal of operation is similar, but the resolution is different. One works on the magnitude of voltage in the pulse train and the other works on the pulse width in the pulse train. This was due to saturation effects of voltage at high RPMs (vehicle speed capability of the new C5/6). So is there a difference ?? Well, yes there sure is.

I am sure the self proclaimed ABS experts around here might not agree, but do your homework on the 8.x system (which came from the precursor 5.3 cpu) and you might just learn something.


This is information I don't have. I'm looking at the basic diagnostic information for the 4th gen Camaro front sensors and the c5/c6 front sensors. Both have the same input impedence and the same output voltage. This tells me that the sensor portion of the assembly is the same. Your contention is that they are different?
The LS1 F-cars use a Bosch 5.3 system. 3 channel in the basic car and 4 channel for ASR/TCS cars. If the Corvette is using the 5.3 system as well, then why would the sensors be different?

edit after thinking about what you said...

although they still give a near the same end product and the principal of operation is similar, but the resolution is different.

They (4th gen Camaro and c5 front hubs?) give near the same output, with that output being an AC voltage (sine wave) which is read differerently by the C5 and 5.3 systems? is this correct?
What then is going to keep the 4th gen 5.3 module from reading the signal from the C5 hub?

[silver69camaro]

I'm really curious to see how this all works in the end. I'm not saying I have doubts, I'd just love to see back-to-back tests!

Chicane67,
As I'm sure you know the scrub radius needs to be considered when setting up an ABS system. Too much scrub can jerk the steering wheel out of the driver's hands when the ABS engages.

[chicane67]

They (4th gen Camaro and c5 front hubs?) give near the same output, with that output being an AC voltage (sine wave) which is read differerently by the C5 and 5.3 systems? is this correct?
What then is going to keep the 4th gen 5.3 module from reading the signal from the C5 hub?

Yes it is a sine wave, but that is the very basic concept of this circuit. This is more of a frequency dependant answer. The frequency has to do more with the resolution.

AC, being a function of voltage over time is the bare bones principal in this. When you turn up the RPM, you lessen the period..... and you get higher frequency. The voltage side of this, only has so much time to go from its max positive potential to its max negative potential. When you turn up the frequency, the time between these two points gets smaller..... and possible saturation of the given circuit can result because the voltage does not reduce enough to have a acceptable %age of duty cycle. This was one case of the older sensors. And now, with the increase in factory showroom vehicle speeds out of the box, the older sensors had some issues with this. So in a fix, they brought the 'working frequency' down out of the stratisphere, to negate the saturation effecets and to also stabilize the the resolution points.

This is where we start leaning towards the BOSCH 8.x system, which is what we have as of 2001..... which was spawned from the 5.3 system. The 8.x is just the 'late model' version of it with a few added bells and whistles.

An eaiser explaination would be similar to a computer processor and its operating frequency or in an actual and practical application, of how many samples can be taken from a data acquisition stand point. Kinda like a 'stepper motor'..... the finer resolution, the more steps, the more accurate....etc. But in the case of the later model sensors, it is coil induction and not the exciter/reluctor type of years past. The pulse width is changed and is longer in duration to exhibit better resolution at higher wheel speeds without saturation.

Yes they can both 'read' the signal, but it is how and what the EBTCM/BPMV does with that signal in respect to its resolution. The resolution itself has a-lot to do with the overall system calibration.


Silver69, yes.... scrub is a small variant in the equation but what you are pointing at is more of a caster induced effect. In the respect of the older model chassis, you bet it has a more specific effect as it acts like caster would.... but to an older design chassis with less initial caster in it. The new stuff likes 6+* caster, because the scrub is under 1.0.

[EFI69Cam]

Yes it is a sine wave, but that is the very basic concept of this circuit. This is more of a frequency dependant answer. The frequency has to do more with the resolution.

AC, being a function of voltage over time is the bare bones principal in this. When you turn up the RPM, you lessen the period..... and you get higher frequency. The voltage side of this, only has so much time to go from its max positive potential to its max negative potential. When you turn up the frequency, the time between these two points gets smaller..... and possible saturation of the given circuit can result because the voltage does not reduce enough to have a acceptable %age of duty cycle. This was one case of the older sensors. And now, with the increase in factory showroom vehicle speeds out of the box, the older sensors had some issues with this. So in a fix, they brought the 'working frequency' down out of the stratisphere, to negate the saturation effecets and to also stabilize the the resolution points.

This is where we start leaning towards the BOSCH 8.x system, which is what we have as of 2001..... which was spawned from the 5.3 system. The 8.x is just the 'late model' version of it with a few added bells and whistles.

An eaiser explaination would be similar to a computer processor and its operating frequency or in an actual and practical application, of how many samples can be taken from a data acquisition stand point. Kinda like a 'stepper motor'..... the finer resolution, the more steps, the more accurate....etc. But in the case of the later model sensors, it is coil induction and not the exciter/reluctor type of years past. The pulse width is changed and is longer in duration to exhibit better resolution at higher wheel speeds without saturation.

Yes they can both 'read' the signal, but it is how and what the EBTCM/BPMV does with that signal in respect to its resolution. The resolution itself has a-lot to do with the overall system calibration.


Silver69, yes.... scrub is a small variant in the equation but what you are pointing at is more of a caster induced effect. In the respect of the older model chassis, you bet it has a more specific effect as it acts like caster would.... but to an older design chassis with less initial caster in it. The new stuff likes 6+* caster, because the scrub is under 1.0.


All this discussion is somewhat moot to the the actual question. Rick and I don't really need to know about the signal resolution in an ABS system that we are not using. As I stated before, the Corvette system is not a good match for my setup where I don't have a LS1 computer in the car. Knowing what a fickle ***** my 99 C5 is with communications between the modules I don't think that system would work without an LS1 PCM and engine in the car.

I see what you are saying about the difference in design, the C5 hub vs a front sensor on a truck is like a HEI pickup coil VS a Mopar toothed wheel and sensor.

If I hook a 4th gen camaro hub to a scope and spin it at 200 rpm, it will produce a sine wave, say 1mv amplitude, and with a certain frequency, lets say 1KHz. Now if I look at the output of a C5 hub, spinning at the same RPM I'm pretty sure the amplitude will be the same (this is in the service manual) but will it output the same 1KHz? :dunno:

I can attach the hub to the module, spin it and look at that channel on the Tech2, but it won't tell me if the speed is actually accurate.

[chicane67]

I don't think that system would work without an LS1 PCM and engine in the car.

Its is only a valid concern if one were to use the ESP and TCS functions. Other than that, as a stand alone system.... it should work. The question is which inputs/outputs that are not going to be used and to shunt them. The controller/pump/accum can be used stand alone, as they have used this same system in the Euro market as an adaptation to exisiting platforms sucessfully.


Now if I look at the output of a C5 hub, spinning at the same RPM I'm pretty sure the amplitude will be the same (this is in the service manual) but will it output the same 1KHz? :dunno:

Amplitude, yes. But the pulse width change (increase) would net a lower frequency at the same RPM.


I can attach the hub to the module, spin it and look at that channel on the Tech2, but it won't tell me if the speed is actually accurate.

Id be interested to see what you find as the difference with the parts that you have. Speed is a calculation of the EBTCM from the function of the wave in frequency. Its factory configured calibration was set to the tire diameter and brake capability, to a known frequency. This is where a re-calibration would be necessary, but can be accomplished by the EBTCM (being a progressive learning computer that it is).

On a side note, I missed all that consipred and what was said after anyone replyed to my post. So cut me some slack if you guys are repeating yourselves. :banghead:

[EFI69Cam]

Its is only a valid concern if one were to use the ESP and TCS functions. Other than that, as a stand alone system.... it should work. The question is which inputs/outputs that are not going to be used and to shunt them. The controller/pump/accum can be used stand alone, as they have used this same system in the Euro market as an adaptation to exisiting platforms sucessfully.



Amplitude, yes. But the pulse width change (increase) would net a lower frequency at the same RPM.



Id be interested to see what you find as the difference with the parts that you have. Speed is a calculation of the EBTCM from the function of the wave in frequency. Its factory configured calibration was set to the tire diameter and brake capability, to a know frequency. This is where a re-calibration would be necessary, but can be accomplished by the EBTCM (being a progressive learning computer that it is).

One a side note, I missed all that consipred and what was said before anyone replyed to my post. So cut me some slack if you guys are repeating yourselves. :banghead:

I am not quite clear yet on what you are saying about the pulse width. If the sensors are constructed like HEI pickup coils then there will be a certain number of teeth, that is what I would see as being the difference. A lower tooth count would be less precise at low speed, but less prone to the saturation effects you were talking about. There might be a different tooth count.

I am going to have to go to the bone yard and snag a 4th gen hub. I'll put it and the c5 hub on the scope and check the wave forms.
I also have the funcky GT-150 pins for the EBTCM connector coming, so I can start the wiring and do the check with the Tech 2.

[chicane67]

EFI69CAM- That is a good analogy. Its very similar. Althought, the sensors in question are not of a tooth and pick-up construction (cogged exciter/reluctor) but the principals of the saturation effect are the very same. Its known as a 'flying coil' but still uses the same principals of induction...... its design however, has been greatly improved for accuracy.

Did you goto GM for the GT-150 or have you found a source for the connector by itself ??

Got your PM...... and I agree. A simple phone call is eaiser than bangin on a keyboard for an hour. We'll be in touch.