G-E's crazy rear multilink idea

  • G-E
    G-E
    Junior Member
    • 6320

    #16
    Re: G-E's crazy rear multilink idea

    or course I could have just drawn a parallel bar system at the back (like half a double wishbone) and a single arm in the front but that won't link camber
  • NissanEgg
    NissanEgg
    Senior Member
    • 5220

    #17
    Re: G-E's crazy rear multilink idea

    The rear bar going from the left to the right still needs to be attached solidly to the body to prevent shift or inadverdent movement like toe or camber changes.

    1986 300ZX Turbo…sold
    1990 Skyline GT-R…new money pit
    2014 Juke Nismo RS 6-speed…daily
  • G-E
    G-E
    Junior Member
    • 6320

    #18
    Re: G-E's crazy rear multilink idea

    one side up one side down would only be the case if you hit a huge bump on the outside wheel while driving in a corner which would increase that wheel's negative camber without changing it's toe

    the inner wheel would go positive and maybe toe-in a touch but that wheel would be lightened by the swaybar so there should be minimal change, but it would still grip well… if the car intends to bounce sideways with the outer wheel off the ground, the inner wheel will still maintain some good traction with the outside edge digging down further with the positive camber, and that toe-in might actually help you smooth the back-end's fishtailing transition back into grip...... like hicas

    btw the rear mount point for the upper bars should be about level with the front control arm attachment so any lift will pull the top inward
  • Benedict
    Benedict
    Senior Member
    • 915

    #19
    Re: G-E's crazy rear multilink idea

    so instead of pulling the Z31 shite out and putting in a proven multi-link (S13/14…Z32, whatever) you're going to take the time to design and fab something almost from scratch that "may" work well.

    Right…

    I wrap my paper weights in glitter.
  • Butter
    Butter
    Senior Member
    • 1519

    #20
    Re: G-E's crazy rear multilink idea

    You are basically designing a totally new suspension, which will take more work than I think you realize. All that really needs to be done to make a bolt in kit is to modify S-chassis subframes to bolt in. Aside from the coilovers, mine will bolt into any Z31 as it sits.
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  • phxZ31
    phxZ31
    Senior Member
    • 598

    #21
    Re: G-E's crazy rear multilink idea

    I'm pretty naive when it comes to suspension stuff.. So forgive me if these questions are pretty basic.

    What exactly is wrong with the stock Z31 suspension? I realize if you lower it you will get excessive negative camber. I can easily understand why you wouldn't want this, especially if its a drag car. But, wouldn't correcting the negative camber be much simpler than swapping in a whole new suspension from another car?
    1985 300ZX N/A -- Schneider Racing Cams + Valve Springs - U/R Underdrive Pulley - Ported/Polished Heads -
    MSA Headers - MGP Intake Manifold - K&N Air Filter - Electric Cooling Fan -
  • G-E
    G-E
    Junior Member
    • 6320

    #22
    Re: G-E's crazy rear multilink idea

    Butter wrote: You are basically designing a totally new suspension, which will take more work than I think you realize. All that really needs to be done to make a bolt in kit is to modify S-chassis subframes to bolt in. Aside from the coilovers, mine will bolt into any Z31 as it sits.
    I know you have a lot experience with your suspension setups, so I know why you like the later s and z hip replacements… but my question was regarding the outcome of what I proposed, the linked camber, and the camber largely seperated from toe changes, all the while being similar in size and shape to the stock z31 pelvis

    no one has said anything about the benefits or drawbacks to what it would do, would having wheels camber together help or hurt the driving experience?

    even if you say it would be bad for drifting or bad for off camber corners or something that would be the kind of feedback I was hoping for… I realize it's a bit weird to people and unfamiliarity usually ends in preaching what you know, but I was hoping people here could try and grasp it, especially the ones with chassis setup experience

    phxZ31 wrote:
    I'm pretty naive when it comes to suspension stuff.. So forgive me if these questions are pretty basic.

    What exactly is wrong with the stock Z31 suspension? I realize if you lower it you will get excessive negative camber. I can easily understand why you wouldn't want this, especially if its a drag car. But, wouldn't correcting the negative camber be much simpler than swapping in a whole new suspension from another car?
    excessive camber and toe changes, not the best thing for a sports car, and unlike a wishbone suspension, limited adjustability and no linearity in the control over the range of motion
  • Benedict
    Benedict
    Senior Member
    • 915

    #23
    Re: G-E's crazy rear multilink idea

    I realize it's a bit weird to people and unfamiliarity usually ends in preaching what you know
    Get the car to do what you want for the least amount of invested time and money. That's why I would push for the S-chassis' multi-link.

    If you pull it off then cool but at what cost and how well will it work.

    Just trying to be practical/cost and time effective.

    I wrap my paper weights in glitter.
  • NissanEgg
    NissanEgg
    Senior Member
    • 5220

    #24
    Re: G-E's crazy rear multilink idea

    You have to take into accounts of pivot centers and their angles within the same control arm(bind), instant roll centers, centers of gravity for the car, anti-squat and anti-dive geometries.
    Then you have to take into account what angles you have as the movable parts swing thru their arcs (for toe, camber, and caster changes).
    Then when you figure all that out, you got to figure out how to dampen the new setup correctly with spring and shocks. Because you will be changing leverage points for the springs and shocks, you will have to do some nerdy math to figure out the correct damping, free height and droop of the springs, etc.

    It can be fun designing something as you go along. But fine tuning it to work correctly will make your head hurt, unless you got friends who happen to be chassis engineers.

    1986 300ZX Turbo…sold
    1990 Skyline GT-R…new money pit
    2014 Juke Nismo RS 6-speed…daily
  • Butter
    Butter
    Senior Member
    • 1519

    #25
    Re: G-E's crazy rear multilink idea

    +1
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  • G-E
    G-E
    Junior Member
    • 6320

    #26
    Re: G-E's crazy rear multilink idea

    well mockup would be fairly easy, the bushing orientations/styles/thicknesses can be changed without affecting the overall design and the spring and shock would still be pushing at points beyond the hub … also the pivot point at the rear for the upper bars could be made adjustable, like an engine hoist arm, choose your hole/height to play with settings, and worst case use pivot ball endlinks

    since we don't have much choice when it comes to springs, it would be a matter of trying the one you think you want (ie stiff like jason's or weaker alternatives), I know the swaybar will have to be significantly beefy, again there isn't much choice and what choice there is is rather similar

    and if I were to do this a camera could be mounted under there to observe it all in motion

    edit: I do see one problem, sidepipes would fix it
  • Butter
    Butter
    Senior Member
    • 1519

    #27
    Re: G-E's crazy rear multilink idea

    please do not try it.


    please.
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