dash2 wheel speed sensor

[trackxsi]

a quick query for the "cleverer" types on here...

i`m 99% ready to ship the wee peugeot off to have everything wired up and only have the wheel speed sensor hurdle left to clear..

at present i beleive i have 3 options

*fit an ABS driveshaft and mount a hall effect sensor to my hub..

*somehow "create" a reference point on my brake disc and mount a sensor to pick that up..

now both are "ok" options but it does mean a bit of fabrication/sourcing parts/expense!

thirdly. (and my current favourite option)..

*on later model 106`s the speedo is driven by an electrical sender fitted into the gearbox (the same hole as the older models take there cable drive from) i would then guess it could be calibrated by driving on a rolling road and settings changed until dash speed = rolling road speed?

(sorry for the essay i hope people are still reading!!)

would this sender unit be ideal to run the DASH2 display??


the sender itself: (not shown is the gear at base driven by the box @ shaft exit)




once again.. sorry for the essay but electrics confuses the bejesus outta me!!!!

stuart

[osborni]

Not sure if the car is already street legal. The easiest way to calibrate the speed sensor is to turn on pulse counting, then go for a drive on a straight road with a solid GPS lock. The system will record the number of pulses and then you can look at the pulse vs. distance graph in Analysis. Just pull the number of pulses per km and there you go.

With this method, I'm within 1 MPH of GPS speed.

You can also switch between GPS speed and Speed sensor speed from within the Dash2 menu. Do some math to get it close, then keep playing with the calibration number until it's right.

The gearbox sensor might be a variable reluctance sensor. i.e., it doesn't produce a clean square wave signal. R_T makes a VRS to Pulse converter though.

Not sure what your hubs are like, but on BMWs where is a bolt that is used to hold the brake rotor onto the bearing flange. I put a bolt on the backside of the flange and then mounted a hall effect sensor through the dust shield to pick up the bolt head.

Alternatively, you can also pick up a bolt head on a drive shaft.

[trackxsi]

ahhh ok...

with regards to the wave issue, (bear with me i failed Alevel physics!)

would it be possible to bang a drill on the drive machanism and let my loom amigo buzz out the correct connectors using his ocsilloscope thing to determine if its useable or not???

will have to get under the car and have another look at the hub/disc area aswell and make provisions for "planB"...


convertor doo-berry???

http://www.race-technology.com/content. ... &cat=30606

[osborni]

Yes, that's the one.

The simple way to tell VRS vs. hall is that Hall effect sensors normally only have 1-4 pickups per wheel revolution. VRS sensors are used on ABS systems and will have ~40 pickups per revolution. If you are sensing gearbox teeth, it's probably a VRS sensor. Hall effect sensors don't react as fast as VRS sensors.

On an oscilloscope a Hall effect is typically a very clean square wave. A VRS sensor looks more like shark fins or saw teeth then a square wave.

[trackxsi]

ahhh ok..

the std peugeot sensor is driven by a gear hung out the bottom of it which engages with a drive inside the box so any trigger pickup will be internal, and of course the sensor is a sealed (fragile french) unit.. i`ll have a drive out to my boffin friend and get his opinion next week..

many thanks for your help...