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  • #31
    The PBM front knuckles are probably a pretty decent choice for a track car out of the existing offerings.
    '18 Chevrolet Volt - Electric fun hatch for DD duty!


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    • #32
      I think I am going the pull the trigger on these soon, I also have a HICAS rack I have been meaning to put in for a while, I wonder how quick the steering will be with these knuckle + HICAS rack... Should be fun!

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      • #33
        I bought the PBM knuckles recently for my s13, being keen on the roll centre / bump steer correction and faster steering. I've got a faster steering rack in a sprinter here which is great w/o power steering.

        A note to anybody buying these for an s13 who doesn't have aftermarket tie rods or LCA's, you need either extended length Rod ends, or to move to s14 inner rods on a stock outer rod according to PBM. I've opted for the extended rod end from GKTech, which I'm not entirely happy about, but it was the quickest option to get the car in for a tune once I discovered the problem. The s14 solution is PBM's recommendation, which I got in an email from their team in NZ this morning.

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        • #34
          What's your issue with the GKTech tie rods?
          '18 Chevrolet Volt - Electric fun hatch for DD duty!


          DefSport Koni Sleeve and Spring Perch Buy!!!
          http://www.nissanroadracing.com/showthread.php?t=5902

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          • #35
            It's a feel thing I guess, I've been burned by them a few times where I've bought things that had machining defects or didn't fit. Ultimately though they are the exact product that you need, and nobody else offers anything to suit.

            I'm overseas atm so I haven't had a chance to drive the car with the knuckles on, but I'll post up some feedback when I get home.

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            • #36
              Any update?

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

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              • #37
                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.
                '18 Chevrolet Volt - Electric fun hatch for DD duty!


                DefSport Koni Sleeve and Spring Perch Buy!!!
                http://www.nissanroadracing.com/showthread.php?t=5902

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                • #38
                  I think everyone is sitting around waiting for someone to try these lol.

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

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                  • #39
                    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?

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                    • #40
                      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.
                      '18 Chevrolet Volt - Electric fun hatch for DD duty!


                      DefSport Koni Sleeve and Spring Perch Buy!!!
                      http://www.nissanroadracing.com/showthread.php?t=5902

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                      • #41
                        Someone give us test results already!

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                        • #42
                          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?

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                          • #43
                            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.
                            '18 Chevrolet Volt - Electric fun hatch for DD duty!


                            DefSport Koni Sleeve and Spring Perch Buy!!!
                            http://www.nissanroadracing.com/showthread.php?t=5902

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                            • #44
                              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.

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                              • #45
                                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.
                                '18 Chevrolet Volt - Electric fun hatch for DD duty!


                                DefSport Koni Sleeve and Spring Perch Buy!!!
                                http://www.nissanroadracing.com/showthread.php?t=5902

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