Front of the car seems to be off while pulling a bit harder.

Discussion in 'Track Prep & Tech' started by HidRo, Apr 3, 2017.

  1. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    Update from yesterday.
    We raised the front 2cm, up to the control arms started pointing down just a tiny bit.
    Didn't seem to make much of a difference.
    We checked everything once more, and everything is in check.

    Went for a drive (although might be a little miss aligned as we raised it) it has the same problem...
    Did a test, fully pushing it in 2nd and 3rd without the hand in the wheel, and it snaps so quickly to one of the sides (does to both sides) it's not even funny. Going ahead, hard 2nd gear and I would hit front first on a 3rd lane car...

    Checking old alignment sheets, I saw the following:
    With shock and spring kit (Bilstein B4 + Vogtland 40mm) it was aligned to 0 toe and -1 camber. Caster was 1.41 (which is within specs)
    Then changed to Coilovers. JOM JNT (height and damp) and mk3 VR6 top mounts.
    It was aligned to 0 toe and -2.25 camber. Caster was 0.34.
    This last alignment was set to the same.

    Question: Camber has such impact in Caster in a stock mk2, or the coils+top mounts changed the caster?
     
  2. Tristan

    Tristan Paid Member Paid Member

    Joined:
    Apr 25, 2006
    Likes Received:
    1,205
    Location:
    Southern IRELAND
    It shouldn't, unless the previous top mounts were shot. Caster is altered by moving either the top mount or the bottom mount in a forward or rearward direction. Usually on a mk2 by offset top mounts, or eccentric rear wishbone bushes.

    The only other thing that could affect caster is dramatically raising or lowering the car, but lowering should have increased the caster slightly.

    So I was right about the offset? At least that is something you can change relatively easily.

    What wishbone bushes are you using?
     
  3. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    Offset of the wheels? Not tried it yet. Should be done this afternoon.

    The mk2 topmounts were in good condition before being removed. Also are these new ones.
    I use the TT/R32 rear bushings in the wishbone, and Protane polyurethane front ones.
    The car has been at around the same height for ages. Ranging from 40 to 60 mm. Not super low or super high heights.
     
  4. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    [video=youtube;CPk7DtZXlzY]https://www.youtube.com/watch?v=CPk7DtZXlzY[/video]
    You can see at around 0.45m that whenever I push a bit more on the pedal, the steering wheel turns like it has life of its own.
    If I push some more, it will be a lot worse.
     
  5. Tristan

    Tristan Paid Member Paid Member

    Joined:
    Apr 25, 2006
    Likes Received:
    1,205
    Location:
    Southern IRELAND
    Are your cv joints ok? Steering UJ?
     
  6. Nige

    Nige Paid Member Paid Member

    Joined:
    Dec 12, 2006
    Likes Received:
    2,138
    Having watched the video. I'm thinking you could have some play in the steering rack.

    You also seem to need a lot of lock to change direction.

    If someone holds the steering wheel whilst you hold a front tyre a 3 and 9 o'clock. If they start turning one way then back again, is there a delay between the wheel reacting?

    If so, you could try replacing the steering universal joint or if that's ok, increasing the preload on the steering rack.

    Also, park the car next to a wall, ideally in a garage between 2 walls. Wedge the front wheels against the walls so they can't move then have someone start wiggling the steering wheel one way to the other. That's how I found my loose steering rack when the bolts seemed tight but I actually had movement.

    That method will show up play elsewhere if you look at the bushes etc whilst the other person is wiggling the steering wheel.
     
  7. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    From what we could see and test, yes. The steering UJ is not even with play anymore, so it's all good there...

    From what I could see you will feel the movement in the steering wheel right away with no delay. I did not test the play in the rack (saw your thread and how you did it).
    I'll have to check the preload of the steering rack (also saw that you did this, so I'll check it again).

    Thanks for the tips guys.
     
  8. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    Update!

    So, got the car aligned again today (several times).
    First we checked to leave toe out without changing anything else.
    This changed nothing.

    Then, got it to -1 camber, it set it to 1 caster (this is due to the geometry) and left it at -0.05 toe out.

    The car runs fine now! When I hit it harder I can feel that there is a little bit of torque steer, but not the massive issue I got in the beginning!
    Also, we discovered that the coilovers have a play in the shaft, which I believe it's not supposed to be there. i'll need to contact the guys about that.

    Tomorrow is the big day, photos and videos should be up in the following days!
    Thanks everyone!!
     
    Nige, Toyotec, Sirguydo and 2 others like this.
  9. Nige

    Nige Paid Member Paid Member

    Joined:
    Dec 12, 2006
    Likes Received:
    2,138
    That's great news. How was the trackday?
     
  10. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    Never got to reply to this.
    Trackday was awesome! I was able to shim off 8s to the time I had before! It's not bad at all, with my driving [:D] ahha
    [video=youtube;a2o3hDQ9hw4]https://www.youtube.com/watch?v=a2o3hDQ9hw4[/video]

    A lot of stuff to go through, but still pretty good.
    Issues were PS fluid boiling over and reaching the brakes.
    And the brakes not braking what they should, even though they are EBC Yellow Stuff. It seems the car doesn't even lock the wheels... (this was before the PS fluid issue).
    Water temps getting up to 120c...

    Getting things sorted for next one, September 30th/October 1st.
     
    jamesa likes this.

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