Setting up traction control
 

Hi all,

Here's how I went setting it up on my car. Certainly it does something, and the ignition cutting hasn't hurt the engine as various people told me it would, but using only the wheel studs the accuracy doesn't seem to be good enough to do smooth TC.

Next step I'll try to find the ABS components to put onto my hubs and use those instead... or make up my own trigger disks but I don't like that idea.

Here's also an intro to one of our most popular race tracks for novices like me to learn on:


This is also the track I'll be driving at the 6 hour regularity in July :)

Great work Andy! Looking forward to seeing how this pans out. It is on my future plans list. :)

What is all required to get traction control working on an RX7? It seems like you have a third party logger and extra sensors. Does the Select ECU have the capability to take 4 wheel speeds as inputs with the rest of the RX7 functions still intact?

EB Turbo

Hi EB, yes the Select ECU has 4 wheel speed inputs.

By default, speed input 1 connects to the gearbox speed sensor signal from the dash, but the other 3 speed inputs are on an internal connector within the ECU. So on my car I don't use the gearbox speed sensor (I have a dash with a mechanical speedo so it needs a speedo cable) and I just have the four wheel speed sensors connected into the ECU. I don't have ABS but I'll be sourcing the hubs / etc for that for my car.

So on the RX7, currently you'd need to add 4 separate wheel speed sensors and wire them in.

I know Motec don't recommend piggybacking off the ABS sensors, and I think that's for liability reasons (ie they don't want people stuffing up their ABS). I have to check the ABS sensor levels on the RX7 to see if we can do that. The wheel speed inputs don't connect into the factory ECU (only to the ABS) so there would be some wiring involved.


The logging setup in my car is:

1) Race Technology DL1 logger, which also does the lap times, G sensing, GPS etc.
2) Race Technology Dash 3 display, which is just for my benefit (I can see lap times, Gs, coolant temperature, fuel pressure etc while driving)
3) Race Technology Video 4 - this takes the 2 camera inputs as well as the data from the logger and overlays the dash picture, and records it as one video stream. It also records the data separately, so in this case I was just looking at the data recorded by the Video 4, not by the DL1 (although it's the same data)
4) Race Technology Adaptronic ECU interface

On the topic of the ECU interface, RT implemented our protocol so it can be logged by the DL1 / Video 4 - and their updated Dash 2 has built-in logging now.

I have found in general these ECU interfaces seem a little bit flakey, in that they sometimes don't communicate and when they don't communicate properly, they don't "recover". Also I kept asking them to implement more channels and it wasn't a priority for them so this gives us more control!

So now you can use that, or you can set the ECU to output the RT data stream directly so you don't need the ECU interface. The only time when you do need the interface is if you need to communicate from the dash back to the logger - for example if you're using a Dash 2 which has separate analog inputs on it and you want to log those as well. In my case I'm only using the Dash 3 / Video 4 as display / logging, no inputs - so I could do it without the interface. I happen to have the interface there because I set it all up before we implemented the RT direct output.

Cheers!
Andy

So you need to open the ECU to access these pins?


Are you reviewing the logs with Adatronic data or RaceTechnology data? To really implement road race style traction control you need to have a proper 2 axis accelerometer. Trying to do it with a single differential to define the steering wheel as being turned is not all too accurate. Another important part is datalogging. If you cannot log the proper channels, Slip%, lateral accel, inline accel,... and view the data correctly, it is difficult to determine proper thresholds. If you are just correcting for large driving errors and not really nitpicking full traction control it will work well enough. It seems complicated enough that most FD owners will never add the wheel speeds to use the traction control feature.

EB Turbo

Yes, you need to open the ECU to access these.

The main benefit I had in mind was to help less experienced drivers put power down especially on cars that come on boost hard, more of an aid to less experienced drivers like myself than as a way for the hardcore drivers to get the last 0.5% of performance.

My experience with the hardcore drivers is that they would kind of be a bit insulted at this suggestion that it would help them! I suggested setting up boost by gear to Ric and he just said "nope, that's my job, I'll do that with my right foot" and talking to some of the pro class time attack (the Australian one... they call themselves "World Time Attack Challenge" which I think could be a little bit of delusions of grandeur) car builders who hire professional drivers and they said the same thing...

I was looking at the data from the Race Technology, and that logs 2 axis Gs as well. I also have a steering angle input into the datalogger, but to be honest that's going to be a lot more hardcore than people other than hardcore race teams are going to go.

For guys looking for wheel speed sensors;

Honeywell GT101 Single Channel Hall Effect Sensor (Wheel Speed, RPM trigger etc)

Damn! That's 'spensive!


Honeywell GT101 Hall Sensor

Thanks Chris !

Got into a situation recently that reminded me to update this info. Tried to use a GT101 on a small diameter 36-1 wheel on a Mazda KLZE and it wouldn't work. Swapped to the Cherry sensor and everything was happy.

One thing to remember when trying to use a Hall sensor, tooth gap and tooth size a important. The GT101, especially, has a fairly large sensor face. That means it's pretty easy to have two teeth on the wheel activating the sensor at the same time, if they're spaced closely together. Here is the datasheet for the GT101. The dimensions for the teeth on the wheel must be observed. http://sensing.honeywell.com/index.php?ci_id=50369

This sensor has a smaller sensor face and that will allow it to run with teeth that have a smaller gap. Cherry "red" Hall Effect Sensor And here it it's datasheet. http://www.cherrycorp.com/english/se...007_Series.pdf While the datasheet describes identical tooth dimensions as the GT101, experience says the Cherry sensor works where the Honeywell will not.

Another option, that's always worked well for me, is using an A/D converter with the stock VR wheelspeed sensors. Saves having to fab mounts to make the Hall sensors fit. Just wire the VR sensors into the A/D converter and allow it to change the sine-wave AC input to the square-wave DC output the ECU wants to see. The Haltech DR2 is an example of such an A/D converter. http://www.lms-efi.com/sunshop/index...t_detail&p=130

Great info! Thanks for sharing :)

Why can't the ECU be programmed to recognize and interpret the analog data from the stock ABS sensors? That sounds like the best method

Two issues.

One, the ECU needs to see a digital signal, not the analog VR signal. So, at a minimum, you will need an A/D converter. Four channel converter gets spendy.

Two, you run into issues trying to split the signal between the ABS module and the ECU. Out can't just splice into the stock harness and connect the ECU or A/D converter in parallel. Splitting the signal requires dedicated electronics to isolate the ABS module. If you've deleted the ABS, you avoid this issue and the A/D converter becomes an attractive solution.

On the Syvecs install we just did, we fitted additional wheelspeed sensors since we were retaining the ABS. We actually used VR sensors with that ECU since it can accept an analog or digital signal. After doing that job, I don't we any way you're going to fit a GT101 or any other Hall sensor that I can think of to the front of an FD. The ABS tone ring sits inside the brake disk. There is just no room to make it work.

So there's really no retaining the ABS and having LC/TC on an FD
An Adaptronic ECU would be a much better value if it could replace both a PFC and Racelogic TC, so that's unfortunate

There is way. It's just not a simple, bolt-on process.

Doesn't the Adaptronic only look at one speed source anyway? If that's the case, a single Hall sensor could be mounted to the rear fairly easily with a little fab work.

I haven't tried this, but I know the Adaptronic can read from 4 x reluctor/digital wheel speed speed inputs (see pic). Except for the e420d which has only 1 x VSS input.

Let me just dig some more info about the piggyback install.

Cheers. :)

Hi guys,

OK, so I just learned that we actually have this interface box/board, to be able to use factory ABS sensors. But it needs to be tested on a real RX7 (we'll be working on it). So then it would do the same as the PFC and the RaceLogic, with the added benefit of being able to interface to race dashes like the Race Technology, Motec etc.

According to Andy, what he found with the reluctor inputs on the ECU is that they’re noise sensitive and if you have ground offsets between the ABS unit and the ECU then you get spurious readings… so hence the box.

I'll report back after we test it, just give me a bit of time because I need to test this on a mate's car.

Thanks.

Interested in this. Sub.

Will this be availabel for the FC? Even though I cut mine out 15 years ago?

Hi Ian, would you know if the FC ones are reluctor types?

Guys, sorry for the delay on this, the test car (my mate's RX7) got actually damaged a week before we were meant to do this.

Unfortunately I do not know. I can provide a drawing if that makes a difference from the factory manual.

Ian

Not that it would benefit an FD3, but this sounds like a great reason to develop a CANbus interface for vehicles that could benefit from it. :stickpoke

Ian, lets have a look, can you email it to me please?

TeamRX8, CAN communications is on the list of features to add, but probably on the next platform ECUs.

Thanks guys!

Any chance you could post a schematic for the box once it's tested?

Will do mate :)

update?

Hi Mdessouki,

Yes we were able to use the ABS wheel speed sensors for launch and traction control, without the ABS system getting upset. However, we found out that aside from the interface board, we needed to add transformers to each wheel speed sensor to couple the signal correctly. I've attached a picture and you'll see how clunky the interface becomes. We definitely need to make something cleaner.

Thanks.

Thanks for the update. My understanding is that if ABS is disabled, one could use a fairly basic circuit to convert the sinusoidal VR output into a squarewave which can be interpreted by the Adaptronic. Is this correct?

Would something like this suffice?
Dual VR Conditioner Board V2.1

Or maybe a GM HEI?
Attachment 547064

I'm not sure I understand the purpose of the transformers when retaining ABS function. Are they being used to amplify the VR output or is it for something else?

Thanks for all the hard work :bigthumb:

Hi mate,

The transformers used are actually just 1:1, but we figured we needed those so we don't mess up with the signal phase of the ABS sensors when we splice to them directly and that's the one that upsets the factory ABS box.

In theory, the Select ECUs should be able to read the ABS sensors directly. But I wanted to make sure first hand so I wanted to try it on an actual RX7. Actually I got to try this on my car's (non-RX7) ABS sensor last week, and it did read the speed, but wasn't reading well at low speeds. So probably the signal really needs to be amplified / conditioned.

I'll give an update soon.

I wasn't aware the select ECU could read the VR signal directly. Why not use a signal conditioner? The MAX9924-9927 was made specifically for this and is pretty much ideal. It has 2 VR signal conditioners on one IC, 100kΩ input resistance, and adaptive peak threshold which will compensate for the lower pulse voltage/noise at low speeds. They are also quite cheap, only about $5 USD a piece :icon_tup: MAX9927AEE+ Maxim Integrated | Mouser

MAX9924-MAX9927 Datasheet

Thanks for sharing mate! Definitely looks like it should work :icon_tup:

Our ABS interface board will do the same, and 1 board has 4 channels/inputs already. I was just testing how well the Select ECUs will read the ABS sensors without the interface board.

Cheers.

Any update mark?

Interested as well.

Hi guys,

I'm very sorry for the delay, I only had the chance to test the ABS sensors wired directly (no interface board) to the Adaptronic the end of last month, and it didn't work well (i.e. didn't read well at low speeds).

So now I'll post the wiring / schematic we currently have on the car, but before I do that, it is important that I say that splicing into the ABS wiring is at your own risk. Don't try to do this, if you're not really comfortable with wiring stuff. Also, we only recommend this mod done on race cars and not on road legal cars.

But yeah, here they are:

Figure 1 is what we did to splice into the factory ABS sensors, without upsetting the ABS control unit. We've used the transformers in between the sensors and the Adaptronic ABS interface board to couple the signal instead of wiring directly. Wiring them directly messes up with the signal's phase and the ABS control unit doesn't like it. The schematic of the interface board is also shown in case you want to make one yourself.

Figure 2 is a case where you have the ABS sensors available, but don't have the ABS control unit or is not working anymore. I.e. so we don't have to worry about it getting upset and throwing a light.

The last picture shows the traction control settings that I used when I tried it on my mate's car.

There is also an option to use a potentiometer to adjust the target wheel slip, so you don't need a laptop when you want to change the sensitivity of the system. However the POT needs to be wired into the ECU's spare / external 0-5v analogue input, so you only have this option if that input pin is free.

If you have questions, please let me know. Post it here or email me at tech@adaptronic.com.au

Thank you.

How do you think the low speed performance will be with the module on a street driven vehicle? Debating abs delete.

Hi Monkman33,

I'm not sure I get what you're asking, but we definitely don't recommend deleting / disabling the ABS system. The wiring and module shown (with the transformers), if done correctly, will not affect the ABS system. The ECU only uses the wheel speed sensors to detect loss of traction while trying to accelerate, and this is where the ECU will be cutting power.

Please let me know if this doesn't answer the question.

Thanks.

Mark,

Sorry i was vague. You said it didn't read the signal well at low speeds with the sensors directly wired to the adaptronic. Is that because the abs was effectively removed? So i am guessing the adaptronic picks up the signal better using the module with all other abs equipment in place?

I'm only considering removing abs because of autocrossing.

Please correct me if I'm wrong.

In the configuration mark posted the wheel speed sensors are being 'tapped' into before the ABS computer using a transformer in order to keep the signals isolated. The transformer is basically 'listening' to the output of the speed sensor, not interfering with it. The poor performance at low speeds is a due to an unconditioned signal. Without proper signal conditioning a VR sensor will only give a usable signal at medium to high speed. Several different sources sell pre-made VR conditioners that could be used. IMHO don't try this in its current state, wait for Mark to release his interface board.

Hi all, was interested in this and I tried to do some more digging on the adaptronic forum, majority of the info on this thread and adaptronic forum is the same. Traction Control and Pulses per rev

Frank said that the board is for sale via adaptronic. I am not quite ready yet myself, but FYI to everyone.
I am interested in seeing the board itself, and perhaps installation instructions for when I am ready/get more time.

Hi guys,

Bowlcutsaresweet is correct in his explanation. Thanks mate!

Silentblu, yes the interface board is actually an Adaptronic saleable product (picture attached) and we sell them for $60+GST if you're in AUS (ask Turblown if you're in US). It's actually a cool board because it has 4 x ABS wheel speed interface, an ignition output expander circuit, a stepper motor driver circuit, and a few more bits. I've posted the 4 x ABS wheel speed interface circuit if one's only interested in that and would want to make one himself.

However, the thing that we didn't expect before I started the test (last year) is that the RX7 ABS system would be unhappy if we tap to it directly. So our solution was to add transformers to "mirror" the signal and this worked, however that adds to the cost now.

So really the best thing for us to do is to make a new interface with the transformers now like bowlcutsaresweet said. But then again we would only make a new product if there's enough demand for it, so I've posted the schematic if anyone wants to try it DIY.

Cheers.
Mark

Frank mentioned it on the adaptronic forum. How would this interface with the adaptronic? Will there be wiring included as well?

For the ignition expander and stepper motor driver, would that mean there would be an additional PWM aux out, meaning I could do the following:

With what I have right now: 440D
Aux 1 PWM - Direct Fire/Ignition 4
Aux 2 PWM - IAC/Idle Control
Aux 3 PWM - Wastegate/Boost Control
Aux X (new interface board) PWM - Auxiliary Injection

With the additional ignition output I would finally be able to do the triple spark plug per rotor!! :lol: pipe dream :crackup:

I would be interested in a premade one. I already have the stepper motor expander to run the omp from less outputs.

Totally off the wall question here, would it be possible to replace the factory sensors with hall sensors on the abs rings?

Mark, what transformers are you using to couple the board? Any links or pics?

Cheers
Glenn

See the beginning of the thread. But I believe Chris answers it pretty well at post #10

BTW how does your stepper motor expander work/interface? Any add'l info?
I need one additional PWM output.

Not sure yet. Haven't installed it. I'm not even sure how to wire it up yet. It is the push pull driver on turbosource.

Silentblu,

- This board won't give you aditional PWM aux outputs, sorry.
- The stepper motor driver circuit allows you to control a stepper motor using only 2 x aux outputs from the ECU, instead of 4, thus saving aux outputs.
- The ignition expander is also meant to fire sequential-six only with the current firmware (really intended to fire the Toyota 1JZ/2JZ non-VVT as sequential).

Monkman33, I think most Hall sensors would be too big for the ABS rings.

Glenn, we used these - LM-NP-1001-B1L Bourns | Mouser

Cheers.

The most common use for the stepper motor driver circuit on a rotary engine would be for the OMP (RX7 S5-S8) and if you're using an e420d or an e440d (so you don't consume 4x aux outputs if you're using the OMP). If you have a plug and play Select, it's already built-in.

This video explains how to use it for a stepper motor idle valve -

Thanks Mark,

I figured the transformers were something like that :) Will put a board together :)

So where did we land on this? I don't follow most the jargon after post #27... Given there were 30+ people that signed up for the $1,000+ racelogic traction control group buy I'm sure you could drum the some interest in a simplified product.

Also, I'm not opposed to adding additional sensors if required.

Any update/ any idea how difficult it will be to set up traction control on the new modular unit?