MM89

Wondering if anybody has used one of these hall effect sensors with ABS rings on NB driveshafts before?

https://au.rs-online.com/web/p/hall-...ta99fj3APohm3Q

Manufacturer recommendations:
Tooth height: 5mm
Tooth width: 2.5mm
Distance between teeth: 10mm
Target thickness: 6.35mm

NB ABS rings are:
Tooth count: 44
Tooth height: 3mm
Tooth width: 2.7mm
Distance between teeth: 3.5mm
Ring thickness: 11.7mm

Quite different in most respects, so I'm wanting to know if this will work before committing.
Setup is MS3X - plan is to use tableswitchin, tps vref for 5v and spare ecu ground.

MM89

Excuse the metric units, taking a punt here...for sake of example I assumed 250km/h

Sensor maximum speed detection = 15kHz

ABS ring OD = 90mm
ABS # teeth (n) = 44

v = 70m/s
r = 0.045m
w = v/r = 1555 rad/s = 14850RPM

tooth passing frequency = (w*n)/60 = 10890 Hz

tpf < 15kHz so all good in the hood?

deezums

iTrader: (3)

Seems about 100 times as fast as normal miata VSS, pretty sure usually tops out at like 150hz at 160 or so.

PT4 can use a hardware timer and so can read a higher frequency, I use it for a EFR wheel sensor that caps at ~1.5KHz, but there's jack **** documenting when it will cap out. It also updates slow as ****, as in maybe ~10hz.

Otherwise everything else uses software timers and maxes out at like 250Hz from what I've read. Might need to divide the frequency down.

MM89

Thanks, good to know. Also came across below video today.


Key points:
- PT4 tested to 2kHz
- Tableswitch tops out at 600Hz

Also been discussing with a mate, alternative way to look at it:

Tyre diameter = 577mm = 0.577m
Circumference = 1.812m
Revolutions per m = 0.552
Velocity @ 250km/h = 70m/s
Revolutions per s = 38.616
Revolutions per min = 2317
by 44 teeth = 1700Hz

Within the limits of PT4. He also suggested to use cam input table switch, with the filter capacitor removed, he tested on a MAF sensor up to 9kHz, which, if going by my previous calc, would still get to 210km/h (input could potentially take more than 9kHz, unknown at this point)

I'll grab one and test to see if it drops out at all on cam input.