Challenge Accepted......

Discussion in 'Members Gallery' started by foxyjay, Sep 28, 2014.

  1. mercedeslimos Forum Member

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    Sweet as a nut. I have G60 hubs and MK3 VR6 flanges drilled to 4x100 and 5x100 M14 bolts and dual drilled G60 discs
     
  2. Alfonzo bonzo Forum Member

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    If if don't throw a code that's good isn't it. Did you check wheel speed with vag com?

    Good work!
     
  3. foxyjay Forum Member

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    It didn't throw a code.....but I now know that the Mk5 Golf (Octavia) wheel speed ABS sensors are "Hall Effect" devices that are the modern alternative to the older style VR (Variable Reluctance) sensors.

    I have grilled TAS on the Ed38 about his experiences when he built the TFSi Lupo and also his Mk2 Golf Rallye R32 conversion.

    He has machined down the front CV joints and then stripped down some Mk5 Golf front wheel bearings to take the fragile magnetic pulse ring and transfer it.
    Then he's had to make / adapt some Mk5 ABS sensors to suit.

    This is a major PITA, and one method I don't want to pursue.

    There are some signal conditioners (electronic gizmos) that allow VR (old type) ABS sensors to be used with ECUs or ABS controllers that expect clean square-wave signals.
    I suspect this is what I'm going to have to look further into.

    The megasquirt guys have this problem and so do a few other similar types of stand-alone ECU users - who don't want the hassle trying to integrate fairly specialised magnetic impulse rings into wheel speed or propshaft signal harvesting equipment.

    I couldn't check wheel speed despite having vag-com hooked up and logging it - the mk4 sensor doesn't fit the Mk5 (octavia) knuckle.
    I'm going to receive the Polo rear hubs any day and I will have a better chance of rigging a test with one of those......as the sensor and ring are already located plus the hub is easier to spin!
     
    Last edited: Oct 17, 2014
  4. Alfonzo bonzo Forum Member

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    Ah ok. I Look forward to your findings.
     
  5. foxyjay Forum Member

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    Plan B Option

    Instead of wasting time trying to remove reluctor rings from old Octavia wheel bearings - I could find a near-match from something available off the shelf, or even have some made to specs.
    www.reluctorrings.com/
     
  6. foxyjay Forum Member

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    Polo 9n rear hubs fit right on to 6n2 sub axles, and have the magnetic reluctor rings......except they are 5x100 pcd and would need redrilling! aargh!
     
  7. mercedeslimos Forum Member

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    Re-drilling isn't a massive problem my local precision eng place did it for 20. Now I have both 4x100 and 5x100 in the bigger M14x1.5 bolts that VR6 and MK4-on have, just means some wheels may need the bolt holes enlarging slightly. Plus it gives me an endless selection of cool wheels and options for adapters to 5x112 and beyond.

    Would the 6N2 GTI hubs you have work with my MK4 ABS setup? At the mo I just have MK2 back discs stubs etc, was going to maybe just use MK3 VR6 rear discs and then double drill them (I have the VR front hubs, and if they work with the MK4 sensors surely the rear ones do) and they slide right onto MK2 stubs, the only downside being the taper roller bearings being a tad weak (16x7.5 ET20 Borbets with 205/50s on...)

    Sam
     
  8. foxyjay Forum Member

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    Yes, the 6N2 hubs have the right pulse rings for Mk4 abs.
    The polo 6N2 / 9N stub axles are parallel not taper, so much better than Mk2 golf fayre.
     
  9. mercedeslimos Forum Member

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    Just leaves finding some! ideally a complete rear axle from an ibiza cupra would be good, I already have MK4 rear calipers (2 sets) and conversion braided hoses so would be the cherry on top.
     
  10. foxyjay Forum Member

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    A pair of stub axles just sold on eBay for 51
    http://tinyurl.com/nybz2nc

    5x100 hubs with magnetic pulse rings built into bearing can be Polo 9n, Ibiza (Mk3?) or Fabia Mk1...
     
    Last edited: Oct 16, 2014
  11. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    Loving this project :thumbup:

    Great work so far Foxy. I'm sure its going to prompt many others too. ;)
     
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  12. mercedeslimos Forum Member

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    Got hold of a focus brake reservoir adapter thing today but it doesn't fit. Bugger. MK4 reservoir is too big so I'm going to have to find or make something
     
  13. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    This was the first time I have been able to read the thread from start to finish.
    I am looking forward to how you complete the exercise.
     
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  14. foxyjay Forum Member

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    B ugger....keep looking - you may find something from another manufacturer's car?
     
  15. foxyjay Forum Member

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    Hours of research later on ABS..........results in slightly better understanding of the technology, but no real solution.

    Some findings, in summary;-

    * Mk2 Golf front knuckles and rear stub axles are abs-ready.
    * Mk2 Golf abs readiness suits wheel speed sensors of Mk2 / Mk3 / Mk4 type - which are Variable Reluctance (VR) type (2-wire)
    * VR abs sensors are simply a ferrous core, permanent magnet and wound-coil - they use a passive pulse ring (toothed / drilled ferrous wheel)
    * Mk5 Golf (and other A5 [PQ35] platform cars/vans) use a 2-wire abs wheel speed sensor which is Hall-Effect based technology
    * The Hall-Effect sensors read an active magnetic sensor ring (of alternating magnetic poles) usually built into wheel bearing end-seals
    [​IMG]
    [​IMG]
    * The Hall-Effect technology have better resolution, accuracy and can (potentially) sense wheel direction - all down to zero-speed
    * It is possible that the 2-wire Hall sensors are MR-Based (Magneto-Resistive) - delivering a signal proportional to magnetic field strength - however this is likely to have been processed on-chip to give a square-wave.
    * The 2-wire sensors are likely to transmit their signal via 7/14mA (derivitive of 4-20mA industry standard 2-wire signal system)

    In summary;-

    > VR wheel sensors do not work with Hall systems
    > VR-to-Hall converters can provide a volt pulse signal but this is a 3-wire Hall system (VCC/0V/Signal) - can't work directly with a current-based (2-wire Hall) system

    I was hoping to find some kind of aftermarket proximity sensor that might do the job - typically like these:
    [​IMG]
    .....however they need to have the right sensitivity, voltage range, directivity (end-on / side-on sensing), frequency range (I estimate 100mph~2kHz signal freq.), and signal type - so pretty tricky to track down!

    I've come full-circle (no pun) and am now looking at possibility of using the original Hall type sensors a-la Mk5 Golf, or maybe others from contemporary VAG platforms with differing body styles, and using some form of active encoder ring.
    Here's a Touareg sensor, for example:
    [​IMG]

    There are some manufacturers of encoder rings in the UK and they can do specials, apparently.
    Next step is to send them some information and see what they can do for me.
     
  16. foxyjay Forum Member

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    During my research, I stumbled upon a handy little off-the-shelf unit mounted in a stock relay type package - which GM use in some Corsa/Astra/etc models to derive a wheel speed signal input from VR sensors and condition it to a square-wave: to drive the electric power steering brain.

    [​IMG]

    Some of you aftermarket ECU guys might appreciate the benefits if you want to add, say, antislip traction control to your application and want to use VR speed sensors?
    It's a Siemens SIEMENS 09.185.826 unit.

    In1/In2 are VR sensor -
    15 - 12V
    31 - Ground
    Out - Output

    I did read somewhere that the output signal was square-wave +1V -> 5V which is handy.

    My electronics days are long behind me..........but wondered if there was a way of converting this into some kind of signal that the ABS ECU could live with?

    [​IMG]
     
    Last edited: Oct 18, 2014
  17. Alfonzo bonzo Forum Member

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    Some really good info here jay, good research!
     
  18. Sirguydo

    Sirguydo Fastest milkman in the West Paid Member

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    I'm glad there are some people with brains that understand this stuff lol

    I like welders and spanners not wires ;)
     
  19. mercedeslimos Forum Member

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    I think most on here like welders and spanners! Though I've come to realise that computerized stuff is a necessary evil... Have you ever driven a W221 S-Class? That will be my next daily, perfect for relaxed comfortable motoring. And my MK2 is the toy then with only some computers yet still enough to make it usable
     
  20. foxyjay Forum Member

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    Here's the rear hub from polo-9n, ibiza, fabia, a2, etc....

    Need to be redrilled 4x100 unless 5-stud is your flavour.

    [​IMG]
     

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