Logging ABS Activation with Motec

I have a TR86 (old championship car) with factory ABS and motec logger. Is there a way to log ABS activation? Currently it's hard to interpret ABS activation by looking at brake pressure of wheel speeds on i2.

Can you share a data file where you know ABS is activating?

try this link: 20240402-0142600 - ABS example.ld

It shows a lap which has lots of very high brake pressure which generally indicates ABS.

Are you sure ABS is activating? You have three channels logged with ABS in the name (all logged fairly slowly for braking events), strangely ABS Warning is a constant 14 -- where does that come from, and what does it represent?

I think ABS might be activating in the area 15.3 - 15.9 sec. Here I see the Front Right wheel going up to 20% slower than the Front Left, and it modulates while the brake pressure is modulating as well. This could also be an example of a good driver just threshold braking.

Another tiny spot is 28.76, where the Right Rear slows then speeds up even as the brake pressure increases a tiny bit.

If we can't tell it from the existing data then perhaps you need to investigate other solutions:

Did the factory ABS activate light on the dash, if so, could you bring that signal into your logger?

Does the driver feel the ABS is activating (pulsing in the pedal or the pedal position changes)? -- if so, perhaps you could add a sensor to measure the pedal position.

Add a brake pressure sensor to the ABS-to-caliper circuits, to identify when the ABS releases the brake pressure.

re: "Are you sure ABS is activating? You have three channels logged with ABS in the name (all logged fairly slowly for braking events), strangely ABS Warning is a constant 14 -- where does that come from, and what does it represent?:"

None of those channels indicate ABS activation, more ABS fault. ie i can look at an entire session and see no logged activity on those 3x channels.

re: "I think ABS might be activating in the area 15.3 - 15.9 sec. Here I see the Front Right wheel going up to 20% slower than the Front Left, and it modulates while the brake pressure is modulating as well. This could also be an example of a good driver just threshold braking."

I think 27s is a better indication of ABS activation based upon general feedback that when the brake pressure shoots up, that's generally due to ABS activation. ie a crude measurement and something i want more accuracy on.

more:

That lap was a generic lap on a damp track which I assume included some ABS activation.

As more background, the TR86 is a Toyota NZ controlled spec race car and can’t be modified.

The brake setup is larger aftermarket callipers/rotors, REMOVED BOOSTER, and factory ABS, plus Motec Dash/logged.

The brake feel is hard and numb. When you get into ABS, the pedal generally goes slightly harder (its already hard though) and doesn’t vibrate.

Its very close racing to say the least and im looking at how to surface ABS activation as a metric for data analysis.

We don’t seem to have a channel for ABS activation, so how else can we detect or math channel calc?

You need to capture some data with known ABS activation. Deliberate mash-on-the-pedal type stuff. Perhaps try disconnect the fuse to the ABS and prove the brakes can lock the wheels with your tires. Log any un-decoded CAN messages and see if anything changes when you know ABS is active.

What does the factory ABS do in a stock car? Does an ABS light on the dash illuminate? Is there a status wire from the ABS, or a CAN message (any clues in the factory workshop manual?)

It seems the ABS system is so effective that I can't detect is from an excellent driver who is threshold braking?