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Bottoming out with Koni Yellows? Solution? Basic suspension tuning?

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  • Bottoming out with Koni Yellows? Solution? Basic suspension tuning?

    I'm thinking that a Koni Yellow and stock spring setup would serve as a solid base for autocross suspension tuning. I've heard some people say that their Yellows don't have enough travel and hit the bumpstops. I've also read that a solution to this problem is to extend the shock body. I'm looking to get some feedback on this issue and its solution and maybe even start a discussion on basic autocross suspension tuning.

    Very informative forum by the way, I like it much more than other 240 forums I've come across.

  • #2
    Yep pretty much the only way to get more travel. Most ppl usually ext. The housing 2-3" if I'm not mistaken. Really wish the rears could be adj. With a knob undead of having to disassemble them...

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    • #3
      This is a great question for Lee Grimes at Koni. Send him an email at [email protected].

      Dave
      NismotronicSA Tuning Package/Powered by TunerCodeSA
      Speed-Density Tuning for Nissans

      Comment


      • #4
        Originally posted by KA240SX808
        Yep pretty much the only way to get more travel. Most ppl usually ext. The housing 2-3" if I'm not mistaken. Really wish the rears could be adj. With a knob undead of having to disassemble them...
        S14 can't, but S13 can use Eclipse rears which are external adjustable.
        Between rides...unless you count a WD21...

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        • #5
          I think you can make the front work with stock springs by changing the bumpstops to stiffer and short ones, giving 1" of travel (I doubt the tall stock coils will bind there). Add a big front sway bar and you'll be good for a while. Some people crank the front rebound damping way up to help fight roll at corner entry.

          What I found more problematic with staying stock is that most stock springs, especially front, have sagged over the years, so you already lost some travel.

          That rear adjustability bothers people too much, especially beginners. It only takes a few tries and then you don't touch it again. I think my rears are overdamped but whatever. For stock springs, leave at full soft or 1/2 turn up. I mean if you're trying to get out there to learn, that would not be the main limiting factor.

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          • #6
            You don't have to hack the housings to get more travel. Drilling a bigger hole in the bottom of the housing and clamping the Koni nut will give you an extra 1/2-3/4" of travel going off memory. That shoul be plenty on stock spellings and a stiffer front bar.
            '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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            • #7
              Thanks guys.

              Originally posted by hai1206vn
              I think you can make the front work with stock springs by changing the bumpstops to stiffer and short ones, giving 1" of travel (I doubt the tall stock coils will bind there). Add a big front sway bar and you'll be good for a while. Some people crank the front rebound damping way up to help fight roll at corner entry.

              What I found more problematic with staying stock is that most stock springs, especially front, have sagged over the years, so you already lost some travel.

              That rear adjustability bothers people too much, especially beginners. It only takes a few tries and then you don't touch it again. I think my rears are overdamped but whatever. For stock springs, leave at full soft or 1/2 turn up. I mean if you're trying to get out there to learn, that would not be the main limiting factor.
              Damn, I've never though about the stock springs sagging it's a good point. I mainly to use stock springs as a learning base and then maybe move up to a GC set later. Are aftermarket bumpstops allowed in autocross?

              Originally posted by Def
              You don't have to hack the housings to get more travel. Drilling a bigger hole in the bottom of the housing and clamping the Koni nut will give you an extra 1/2-3/4" of travel going off memory. That shoul be plenty on stock spellings and a stiffer front bar.
              Good info., but would this be allowed for autocross?

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              • #8
                Would these be allowed? Why not? Just modify it however you want, register in the class that allows those modifications, and drive.

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                • #9
                  I don't see how it wouldn't be allowed in even stock class. They're just replacement inserts. SCCA allows way more exotic stuff for dampers in every class I can think of.
                  '18 Chevrolet Volt - Electric fun hatch for DD duty!


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

                  Comment


                  • #10
                    I have koni yellows.
                    Look at D-Rex strut extenders. They are for Subu's but will work on our shocks.
                    You have to file down the bottom of our struts flat which isn't to bad.
                    They extend the travel strut by like 1", I also cut my bumpstops down to like .75 inches and I never hit them any more (zip-tie test.)

                    But I do have stiffer springs, with shock springs I'm not sure you still won't hit the bump stops. Also I have no idea of the strut extenders would be against the class you are in for autox.

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                    • #11
                      IIRC stock front strut has about 3.5"-4" compression travel at static weight, but the stock bumpstop also eats up 2", leaving you with 2".

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                      • #12
                        Originally posted by modulation
                        I have koni yellows.
                        Look at D-Rex strut extenders. They are for Subu's but will work on our shocks.
                        You have to file down the bottom of our struts flat which isn't to bad.
                        They extend the travel strut by like 1", I also cut my bumpstops down to like .75 inches and I never hit them any more (zip-tie test.)

                        But I do have stiffer springs, with shock springs I'm not sure you still won't hit the bump stops. Also I have no idea of the strut extenders would be against the class you are in for autox.
                        what springs are you running?

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                        • #13
                          Originally posted by floodo1
                          what springs are you running?
                          I'm running the megans. They are 350/250.

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                          • #14
                            Originally posted by modulation
                            I'm running the megans. They are 350/250.
                            I'm not sure if I trust megan's advertised spring rates since I've seen them advertised as many different rates. When you changed your dampers, did you change from the stock springs to the megan's at the same time, or did you change to the megan's at a later date? I'm curious if the megan's feel 3X stiffer than stock. I've never seen the megan's in person, but from the pictures of them, their wire diameter and active coil count doesn't look as beefy as I'd expect for a 350lb spring, but it is so hard to tell.
                            -Dennis
                            92 240SX Coupe
                            93 MR2 Turbo
                            75 Celica GT
                            07 CBR 1000RR

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                            • #15
                              Originally posted by DBM
                              I'm not sure if I trust megan's advertised spring rates since I've seen them advertised as many different rates. When you changed your dampers, did you change from the stock springs to the megan's at the same time, or did you change to the megan's at a later date? I'm curious if the megan's feel 3X stiffer than stock. I've never seen the megan's in person, but from the pictures of them, their wire diameter and active coil count doesn't look as beefy as I'd expect for a 350lb spring, but it is so hard to tell.
                              I changed everything over at once. They probably just aren't a consistent 350/250 under pressure which is what I hear the deal is with cheap springs.

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