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  • sw1fty
    replied
    Has anyone got any experience with the below knuckles?
    They sound good in theory and I like the use of the 350Z bearing. I am hesitant to buy something when I can't find any feedback on them.

    https://www.fdfraceshop.com/products...-grip-knuckles

    Leave a comment:


  • OddyseusDSM
    replied
    I have a question. Ive read that a good starting point is to put my control arms parallel to the ground so that I don't mess up the roll center to bad when lowering the car (S14). I ran into an issue since I run z32 wheels and decided I'd try to lower the car to 4mm from the tire (coilover perch to tire with 5mm sandwich spacer). I check the control arms and find that they are about parallel to the ground at about .5" under stock height.

    I can put the TT rears on the front and lower another inch but is that worth it. Might look better.

    Am I overthinking this?

    S14
    BC BR coilovers 10k/8k
    Currently 26.75"f 26"r
    Stock 27.3"f 26.1"r

    Any suggestions, other than buy new wheels and tires?

    Leave a comment:


  • McRussellPants
    replied
    Originally posted by Def View Post
    For drifting I have no idea what's best.



    It's not great.

    Leave a comment:


  • Def
    replied
    Originally posted by McRussellPants View Post
    Fwiw some of the wisefab kits have negative Ackerman.

    One of many reasons why wisefab is hot garbage.
    See post above. Tire theory actually leads towards negative ackerman for ultimate steady state grip in a corner. The more normal force on the tire, the more slip angle it takes for it to generate peak grip. So you want more angle on the outer tire.


    For drifting I have no idea what's best.

    Leave a comment:


  • McRussellPants
    replied
    Fwiw some of the wisefab kits have negative Ackerman.

    One of many reasons why wisefab is hot garbage.

    Leave a comment:


  • Def
    replied
    I know they're a bit different, but lots of formula cars run negative ackerman.



    The theory being the lower loaded tire (inside) will generate peak grip at a lower slip angle than the outer tire that's loaded more heavily.

    So something close to zero ackerman is probably not so bad on track. Stock ackerman is for driving around a parking lot at low speeds and lateral loads, so I wouldn't apply it to even cone packing.

    Leave a comment:


  • dirtyD
    replied
    That actually makes things much simpler. One part and done. Was looking for faster steering anyways. Worse case scenario I sell them if it doesn't work out. A little worried about autocross but I've been planning on moving more to track days anyways. Thanks for the feedback.

    Leave a comment:


  • Def
    replied
    I think my car drives just fine with really low ackerman. It scrubs a bit at low speed, but seems fine on track. It's reduced inside inner tire wear that seems to happen on strut based cars with stock ackerman. I think the inside wheel turns more, and it ends up being scrubbed across the ground and not gripping much on the inside portion. It's inside where normal camber wear occurs.

    So I'd say go for a drop knuckle. More RC correction than this might help, but I think it's diminishing returns to get it "good." As you might get a small roll couple at static ride height, then you go in a corner and it shoots out 1000x farther out than at static. That's going to make the car drive oddly. Putting it just a hair above ground level tends to make it not migrate as much with roll.

    Leave a comment:


  • dirtyD
    replied
    Bump for results.

    Sorry if these are noob ideas but I figured this would be the best place to ask.

    About ackerman, what about relocating the steering rack slightly back to get it closer to stock? Or does that not work the same as moving the rack forward to decrease ackerman?

    Or . . .
    Originally posted by Def View Post
    It's sizable, and when you correct the RC with a longer shank on the balljoint, it goes up further. Same when you correct bumpsteer via the tie rod.
    I haven't begun to wrap my head around that but could you run the drop knuckles with an extended shank to add some ackerman back in?

    I have been debating running GKtech's RC correction kit with a higher offset wheel to negate the added scrub but as far as I can see no results have been posted for those either.

    Any new developments in the front RC game?

    Leave a comment:


  • Skepticism
    replied
    Someone give us test results already!

    Leave a comment:


  • Def
    replied
    Meh, just weld on some new tabs if you want to keep using your S13 subframe. Just bolt them up to the arm, tack on subframe, then unbolt and weld out.

    Leave a comment:


  • tmas_the
    replied
    I'll update soon on mine, I've got them on and nipped around the block a few times, but haven't had enough time to get the car to an alignment or onto the track.

    I saw this photo the other day that a workshop here posted. Interesting LCA brackets to reduce antisquat on the s13 subframe. I contacted them about the brackets but haven't had a reply yet. Thoughts?

    Leave a comment:


  • e1_griego
    replied
    I think everyone is sitting around waiting for someone to try these lol.

    I'll pull the trigger soon and see what's what.

    Leave a comment:


  • Def
    replied
    It's sizable, and when you correct the RC with a longer shank on the balljoint, it goes up further. Same when you correct bumpsteer via the tie rod.

    Leave a comment:


  • e1_griego
    replied
    Any update?

    Also what's the stock ackerman in a 240? I see the PBM chart but how does that compare to stock?

    Leave a comment:

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