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
    Hi guys,

    I'm on a short deadline (this Saturday the 8th) to the trackday, and the car is not behaving as it should even after the LSD installation.

    When I pull "hardish" (maybe 290hp with 0.8bar setup) on a straight line, even if I hold the steering wheel straight, the car seems to be hovering around. The front seems to be chasing something. I thought that this would be corrected with the LSD making it pull straight all the time but it seems to go side to side, even with the steering wheel straight. I have no whishbone slack, new top mounts, new suspension, no issues with the engine/gearbox mounts, rear bean is in good shape and no slack as well.
    Car was aligned (-2.15 camber, stock caster and toe). I have no idea of what it can be....
    Do any of you suffer from this or have you suffered in the past and corrected it?
    Thanks a lot!
     
  2. Tristan Forum Junkie

    Joined:
    Apr 25, 2006
    Likes Received:
    265
    Location:
    Southern IRELAND
    Walking on the inner edges of wide tires?
     
  3. Nige

    Nige Paid Member Paid Member

    Joined:
    Dec 12, 2006
    Likes Received:
    2,135
    Check for worn bushes on the wishbones where they connect to the subframe.

    Is it excessively lowered? Do you have big spacers? All these things can affect handling
     
  4. vw_singh Events Team Paid Member

    Joined:
    Oct 29, 2003
    Likes Received:
    775
    Location:
    United Kingdom
    Sure there isn't play in the steering rack or UJ?

    Gurds
     
  5. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    60max lowered up front. No spacers and no wishbone bushes worn. No play in the steering rack and a tiny bit in the UJ, but this was happening with non powered steering and no play in anything there.
    I've had the camber to -1 and the same issue.

    Sent from my Redmi Pro using Tapatalk
     
  6. Tristan Forum Junkie

    Joined:
    Apr 25, 2006
    Likes Received:
    265
    Location:
    Southern IRELAND
    Have you changed the offset?
    Bear in mind you've more than doubled the power it was built for.

    Top mounts definitely good?
     
  7. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    Yeah, top mounts were brand new mk3 VR6 type mounts.
    Were installed with the coilovers.
    Offset of the wheels? It's the same set of Ronal LS 15x7.5 ET 25? I've had for years!
    I understand that the power is way over what it was build for, but there are a lot of guys using the same chassis without issues (Nige for example). I would like to have the same... :p
     
  8. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    I went out to test some more stuff:
    - damping set to the hardest in front, softest rear - Same issue.
    - damping set to the hardest in the rear, softest front - same issue (although seems a bit better).
    - damping set to the max all around, same issue.
    checked tire pressure, was to 31psi although I asked to set to 26... raised to 36. same issue.

    Tested a 3rd gear spool, still at 0.8bar (12psi) and when boost kicks in, it will rotate the steering wheel to the right. When cruising soft, it goes to the left.
    When I'm hammering it in a straight line, I need to correct it constantly.
    I'll need to test (did not have time to do so) the tires at 26psi.
    Any input is VERY appreciated!
     
  9. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    [​IMG]
    This is the alignment report.
     
    Last edited: Apr 4, 2017
  10. pascal77uk Paid Member Paid Member

    Joined:
    Jul 12, 2006
    Likes Received:
    382
    Location:
    Glos
    There's got to be play in something. I'd check the whole front end again, spanner check the lot. I guess when jacked up everything feels tight but when on full throttle and laying down near 300 and the diff is working hard something is moving about.

    Also I'd try dropping the camber to -1.5 and go to ET35 wheels. Don't think it's the issue but be worth looking at. Also any spigot rings in there on the Ronals.
     
  11. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    No spigot rings on the wheels.
    Something is off, that's for sure.
    Talking with some friends that do trackdays as well, they say a bit of toe out might resolve some of the wondering around.
    The Caster does seem to be quite low, doesn't it? Pulling the subframe a bit to the front might help?
     
  12. Tristan Forum Junkie

    Joined:
    Apr 25, 2006
    Likes Received:
    265
    Location:
    Southern IRELAND
    Definitely you need more caster. Which will allow you to Run less camber.
     
  13. vw_singh Events Team Paid Member

    Joined:
    Oct 29, 2003
    Likes Received:
    775
    Location:
    United Kingdom
    Has the car been driven as it is now without this issue before?

    If no, what has changed since it last drove well?

    Your car sounds like it has a loose component like a tie rod/ball joint/ rack play etc. If it only did it on boost I'd say it was torque steer from running low offset wheels but as it does similar when cruising then something is loose or worn.

    Zero toe is perfectly fine. Toe out has never worked for me.

    Gurds
     
  14. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    Well, I remember the car driving good and I hammered it like a SOB before having the engine in. After the engine was in, not sure if it was the fear of it being a lot more powerful but it felt strange.
    Now, I know it's not about the power, but the car it self is strange, so I don't know exactly what was the culprit for this.
    I know that before PAS it did the same, with PAS it's the same. The LSD shows the issue more. Before I believe it would just start spinning when it would want to go side to side and then I would know I had to be extra careful.
    When driving hard, it's like the steering is ULTRA SHARP, more that one would expect and like. Any small correction will make the car jump lanes basically.
    Could the wheels do this or get this worse?
    I can try to get another 15" set and test for sure.
    BTW: ET25 but they are 7.5", so would that change the idea of it being too low offset?
     
    Last edited: Apr 5, 2017
  15. vw_singh Events Team Paid Member

    Joined:
    Oct 29, 2003
    Likes Received:
    775
    Location:
    United Kingdom
    Ok, that helps. So to summerise.

    - Before you had an LSD, the car still did this but less so.
    - After increasing power, it got worse.
    - After fitting an LSD it got worse.

    You have two problems from what I can see. This is given that all else is mentioned is in good condition. Replace the UJ as from experience this causes some of what you are experiencing.

    1. Your scrub radius is out with the low offset wheels. You have positive scrub which causes torque steer and tram lining. Easiest fix is to use et35 or higher wheels and see how it feels to identify it. Width isn't the issue here.
    2. You have bumpsteer which causes the issue to be worse on uneven roads. Probably fine on perfectly flat roads. Do you have factory tie rod ends etc or are you using custom stuff? Anything on the hub or ball joints that isn't factory? Even the factory car has bumpsteer which will cause issues at high output.

    Gurds
     
    Jon Olds likes this.
  16. Tristan Forum Junkie

    Joined:
    Apr 25, 2006
    Likes Received:
    265
    Location:
    Southern IRELAND
    Wonder is the rack moving like Niges was.
     
  17. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    Everything is factory spec, no custom parts there.
    I'll have to check the UJ then. Is this still sold new or I need to get to the breakers?

    I remember seeing something like this in his topic. Will check.
    Thanks!
     
  18. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    AFter reading this, it seems that I might have an issue with the wheels, as you mentioned.
    Scrub radius, and offset importance
    http://clubgti.com/showthread.php?228182-Scrub-radius-and-offset-importance

    (this has pictures and all, which facilitates the sync in process).

    I do have a set of 15" wheels that are ET37. Would this be a safe bet to test?

    BTW, I did install the wheels close to the time I put the engine in.
     
  19. vw_singh Events Team Paid Member

    Joined:
    Oct 29, 2003
    Likes Received:
    775
    Location:
    United Kingdom
    Exactly! Scrub radius is very important on a high powered FWD.

    Yes fit those ET37 wheels so long as they clear the shocks and springs.

    Gurds
     
  20. HidRo Forum Member

    Joined:
    Jan 30, 2004
    Likes Received:
    12
    Location:
    Portugal
    Might even ask a friend to lend me a set of BBS RA's which are stock, and should fit without any issues. That would not need an alignment to test I guess..
    Thanks for the tips everyone!
     

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