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-   -   traction control tapping into abs lines (https://www.miataturbo.net/suspension-brakes-drivetrain-49/traction-control-tapping-into-abs-lines-73429/)

skir 06-19-2013 05:10 PM

traction control tapping into abs lines
 
So I have an adaptronic e420c which I've had modified by the adaptronic importer over here to have the necessary 2 extra inputs so I can have a sensor peer wheel. I also have a guy who can put together the reluctor converter circuits to change the wave form from a analogue to digital type that the ECU needs.

The circuit has been tested working on a 5 that does not have abs fitted.

As my car has abs fitted I was thinking about tapping into the abs lines to use the stock abs sensors and trigger wheels to provide the signal to the ECU.

What we are not sure of is if going down this route, will the abs continue to function or throw up error codes/dash lights and wool the tc work?

Can anyone confirm if this method will work or not?

If it will work are there any other adaptations I need to make to the setup?

soviet 06-19-2013 05:17 PM

only one way to find out
in for results

Braineack 06-19-2013 05:19 PM

I dont see how it will be an issue depending on the input circuit, especially if opto...

Joe Perez 06-19-2013 08:47 PM


Originally Posted by skir (Post 1023187)
I was thinking about tapping into the abs lines to use the stock abs sensors and trigger wheels to provide the signal to the ECU.

What we are not sure of is if going down this route, will the abs continue to function or throw up error codes/dash lights

Yes, with a but:

You're describing "a guy who can build a circuit." Provided that "the guy" builds "the circuit" in such a way that it has a high input impedance (eg: 10s of kΩ) and does not apply any sort of pullup voltage to the sensor, then yes, it will work just fine.

These criteria (high impedance, no pullup) are usually assumed to be true of any input circuit designed to receive a signal from a VR-type sensor (eg: ones based on the MAX9926 IC), however speaking as an electrical engineer, I can assure you that you can always find a way to fuck up even the simplest circuit design if you try hard enough.

I predict a 95% chance of success, presupposing that "the guy" is a competent engineer.

(I'm assuming that the Miata does, in fact, use VR sensors on the ABS. I have utterly no idea if this is true- I've never owned one that had ABS.)




and wool the tc work?
I doooooont know.





Can anyone confirm if this method will work or not?
Yes. You can.

Savington 06-19-2013 09:15 PM

Does the Adaptronic have the ability to cut injector pulses, or is it just going to retard the timing and blow the motor up?

skir 06-20-2013 03:49 AM

Thanks for the replys so far.


Originally Posted by soviet (Post 1023191)
only one way to find out
in for results

Yeah I'm tempted to just do it, however I've done that before with unintended results. :giggle:


Originally Posted by Joe Perez (Post 1023254)
Yes, with a but:

You're describing "a guy who can build a circuit." Provided that "the guy" builds "the circuit" in such a way that it has a high input impedance (eg: 10s of kΩ) and does not apply any sort of pullup voltage to the sensor, then yes, it will work just fine.

These criteria (high impedance, no pullup) are usually assumed to be true of any input circuit designed to receive a signal from a VR-type sensor (eg: ones based on the MAX9926 IC), however speaking as an electrical engineer, I can assure you that you can always find a way to fuck up even the simplest circuit design if you try hard enough.

I predict a 95% chance of success, presupposing that "the guy" is a competent engineer.

(I'm assuming that the Miata does, in fact, use VR sensors on the ABS. I have utterly no idea if this is true- I've never owned one that had ABS.)



I doooooont know.




Yes. You can.

I should have quantified who the 'guy' was really, sorry. He's certainly an auto electrician as a minimum but has some other strings to his bow I think. I became aware of the board he put together on this thread. Pics of the board about half way down. I'll chat to him about the points you make, electrical stuff ain't my forte tbh.

Malcolm's Race Car Build - Page 56 - Members Rides - MX5Nutz Forum - Page 56


Originally Posted by Savington (Post 1023264)
Does the Adaptronic have the ability to cut injector pulses, or is it just going to retard the timing and blow the motor up?

Yes it can cut fuel and/or ignition.

Reverant 06-20-2013 05:35 AM

Looks like a very simple circuit, with a diode to rectify the voltage and a transistor to make it a square wave. No zero-crossing detection.

skir 06-20-2013 11:39 AM


Originally Posted by Reverant (Post 1023361)
Looks like a very simple circuit, with a diode to rectify the voltage and a transistor to make it a square wave. No zero-crossing detection.

From a little reading zero crossing detection would be beneficial? Will I encounter problems without it?

From looking at the Mazda workshop manual for this year a sine wave is what to look for with an oscilloscope to check the abs is running correctly so I guess it must be a reluctor type.

skir 06-20-2013 02:05 PM

..... or they could be current loop hall effect?

DaveC 06-22-2013 11:57 AM

IIRC the cable from each sensor is a shielded twisted pair, which suggests (to me) VR. If it were me, I'd just use a MAX9926, which is properly differential, and be done with it. I can't imagine why anyone would try to build a fussy, discreet, SINGLE ENDED circuit.

EDIT: I wrote that without following the link. The circuit on the board is not single end as I'd assumed. It'll be interesting to see how the OEM abs computer feels about it.

Joe Perez 06-22-2013 04:19 PM

Without a schematic, it's impossible to know for certain.

So long as he's not grounding out one side of the signal, it'll probably work just fine.

DaveC 06-22-2013 08:48 PM

Joe speaks truth.

skir 06-24-2013 01:24 PM

OK, thanks for all the advice. I'm going to give them a go. At about $30-35 dollars for 4 circuits they are worth a punt. I'll post up here with results when I have them. That may be a while though as I think I've damaged my clutch thrust bearing on track over the weekend.

Braineack 06-24-2013 01:28 PM

wait? how is 4 diodes and 4 transistors $30-40????

Joe Perez 06-24-2013 02:30 PM


Originally Posted by Braineack (Post 1024581)
wait? how is 4 diodes and 4 transistors $30-40????

Labor.

Some of us value our time.

skir 07-15-2013 07:29 PM

Just thought I'd add that the circuits got installed today and so far they are working perfectly! Thanks for all your advice and comments.


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