Fitted Corsa EPS - Are you happy with it ?

Discussion in 'Chassis' started by Ade.Mk1, Nov 21, 2010.

  1. Ade.Mk1 Forum Member

    Joined:
    Oct 24, 2003
    Likes Received:
    1
    Location:
    Staffordshire
    A few months ago I fitted a Corsa C electric power steering to the wife's Sportline cabby - the unit was supplied by CrazyQuiff, a superbly engineered solution that had been MIRA tested - this was an important point for me.

    Well it took a weekend to fit, took my time to make sure that I got everything spot on !!

    The Corsa steering ECU requires two signals from the car, ignition pulse and speed of vehicle - both of these are faked by a simple dual 555 timer circuit with the speed signal being variable via a dash mounted POT.

    So out for a road test !!
    At stationary or parking speeds the unit is superb, the steering is very light, single finger turning of the wheel from lock to lock.
    Out on the road though the story is very different, even with the amount of assistance at the lowest setting the steering still felt vague and would not centre from about a quarter turn each way, this made the car interesting to drive coming off corners !! You found yourself having to wheel the steering wheel back to the centre.

    Obviously it could not stay like this, but the wife refused to allow me to put the manual setup back on (everything is bolt on, bolt off reversible) as she really liked the ease at which she could now park the car !! So she put up with the vagueness and loss of self centre until I could find a solution :-)

    I knew what was going on, the power steering was absorbing the centering feedback due to there being too much assistance at speed, this was also responsible for the vagueness. My first thoughts were that I need to alter the 555 timer circuit so that I could get more assistance removed, however this would then require the constant turing up and down of the assistance - not really a solution. After a bit of surfing I came across a VW Type 25 forum, enter Richard Jones who runs rjes, he specialises in the conversion pieces required to allow Subaru engines and gearboxes in T25's. He has perfected the Corsa power steering conversion for these vehicles and his system does not fake the vehicle speed signal but provides a real one !!! At this point I was really excited that I might be able to get the steering working as Vauxhall intended.

    The speed signal comes from the VW speedo, Richard adds a second sensor above to the existing one, picks the power up and routes a flying lead out. The existing sensor cannot be used as it does not provide enough pulses per revolution for his control until to smoothly alter the assistance.
    See these pics for the sensor that is modified:

    [​IMG]
    [​IMG]
    [​IMG]

    Richard's solution uses a small control unit that has two buttons and a 7 segment display, it takes the pulses from the new speedo sensor and creates a real speed signal for the Corsa's ECU, I have hidden in inside the centre console, here is a pic of it:
    [​IMG]

    The unit has two adjustable parameters A and r, A sets the maximum possible assistance, it is important to not set this too high because even at parking speeds you can make the steering too light and vague. r sets the rate of assistance and is calculated based on the number of pulses coming from the speedo and the rolling radius of the wheels fitted - this means that the system is very flexible to suit the fitment of very large wheels. Both of these values can be altered by the end user, meaning that changes to the cars wheels or rack (maybe a quick rack) can be compensated for.

    Once fitted the transformation was amazing !!
    Full centre control has returned, the vagueness has completely gone and it is still brilliant at parking speeds - result :-)

    Richard can be found here:

    Richard Jones Engineering Soluions
     
  2. Dave

    Dave Pedantic Old Fart Paid Member

    Joined:
    Feb 26, 2007
    Likes Received:
    440
    Location:
    Sligo, Eire
    Nice post Ade.:thumbup:

    It is not something I would want myself, but for those who do, I think that you have ticked all of the boxes![:*:]
     
  3. Admin Guest

    is there a FAQ on these corsa PAS? this should be added:)
     
  4. Crispy 8V CGTI Committee - Club Secretary Admin

    Joined:
    Oct 23, 2003
    Likes Received:
    116
    Location:
    NW
    I have fitted a corsa kit, on stock rack and stock suspension set up it felt very simalr as you've decribed, odd to drive at first

    after putting a quick rack on & altered camber/caster settings it feels so much better and presise
    one of my next little project would be to experiment with the inputs and intergrate it mk4 wiring
     
  5. 2dubnick Forum Junkie

    Joined:
    Nov 22, 2006
    Likes Received:
    1
    Location:
    Worcester
    Interesting read, wanting to squeeze one into the cabby at somepoint.
     
  6. Vento Mike Forum Junkie

    Joined:
    Oct 22, 2003
    Likes Received:
    1
    Location:
    Exmouth
    Nice write up mate good work.
     
  7. Ade.Mk1 Forum Member

    Joined:
    Oct 24, 2003
    Likes Received:
    1
    Location:
    Staffordshire
    Cheers guys, thought it was worth sharing.
     
  8. tshirt2k

    tshirt2k Forum Junkie

    Joined:
    Oct 21, 2004
    Likes Received:
    325
    Location:
    Herts
    Definately :thumbup:
     
  9. just german New Member

    Joined:
    Jun 6, 2011
    Likes Received:
    0
    EPS conversion

    hi i am from Souith Africa and we had the MK1 Shape up to 2008 i see you have converted your MK1 to EPS i contacted the guys on your link but the price to land the kit is over R12000 in our money, do you have a manual or some some of info i can use i can get hold of the corsa C EPS what else would i need Steve
     
  10. Handpic New Member

    Joined:
    Oct 3, 2011
    Likes Received:
    0
    Signals for electrical power steering in Corsa C.

    Hi,

    I am looking information about signals of steering electronic in Corsa C.

    I would like to emulate this signals. I think this steering need rpm signal and speed signal and I need to know between What value of sign and what type they are?.

    Thanks for your help.:thumbup:
     
  11. Kazan New Member

    Joined:
    May 7, 2010
    Likes Received:
    0

    Crispy 8V ,

    What changes did you make to your Camber & caster to correct for the EPS ?
     
  12. KeithMac Forum Junkie

    Joined:
    Oct 27, 2003
    Likes Received:
    67
    Location:
    Kazakhstan
    My friend actually helped in designing the predictive motor control on early Vauxhall electric steering systems, you cannot just feed it a random road speed etc as the whole system is designed around steering effort predictions based on vehicle speed and steering angle, plus torque strategys based on the brushless motors.
     
  13. Crispy 8V CGTI Committee - Club Secretary Admin

    Joined:
    Oct 23, 2003
    Likes Received:
    116
    Location:
    NW
    I've messed with this a couple of times, bit more when the car was used as a daily. caster settings are a increase and the cambers has ended up between 1-1.5'
    the center position of the column need setting via the potentiometer as well, this more helped with the self centering

    I fully understand whats needed to develop something like that to get right, then we expect to rip it out, put it in something else and expect it to work off the key ! lol

    I would be interested in in the frequency / number of pulses for corsa road speed, ie 30 & 70 mph, the 555 chip solution gets it working buts not right, keep planning to revisit this - every time i drive the car!!
     
  14. The ANT Forum Member

    Joined:
    Aug 28, 2013
    Likes Received:
    25
    If you want information on this you need to talk to thw mk1/2 ford escort lads.
     
  15. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    2,936
    Location:
    Bracknell
    Crispy 8V likes this.
  16. sparrow Paid Member Paid Member

    Joined:
    Jan 2, 2006
    Likes Received:
    741
    Location:
    Leamington Spa
    That's interesting, I'm pretty sure our DTA ECUs can control that! I'll need to find some time to write up an article. [:D]
     
    rubjonny likes this.
  17. Crispy 8V CGTI Committee - Club Secretary Admin

    Joined:
    Oct 23, 2003
    Likes Received:
    116
    Location:
    NW
    i have seen that when fitting mine, hes updated the page with useful info regarding pulses & duty cycles, maybe this winter lol
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice