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  • 240sx to STX Proposal

    http://scca.cdn.racersites.com/prod/...es%20Draft.pdf

    Looks like the STX move is out for member comment. I had argued that the S14 seemed to be a better fit in STX, but it looks like they might move both chassis over. Any arguments to having a real diff and bigger tires in the ST* category? Also curious to see what other people think of going against the twins, E36, and RX-8 on street tires.

    Def: How light could you get an STX legal brake setup?

    Another curiosity is the Member Advisory from the December Fastrack:
    Per the STAC, ball joints and heim joints are considered to be of the same type, and thus replacement control arms utilizing one or the other versus Stock would be in compliance with 14.8.B. Note that this allowance does not open up modification of the mounting point (i.e., tapered holes may not be converted to non-tapered).
    I wonder if that makes it worth using LCA's for camber adjustment instead of camber plates...

  • #2
    The stock FLCA bushing is pretty horrible, so I think there's a big gain with getting rid of that. Too much camber loss there, and it's so large there's a distinct "loading up" phase before the front does anything.

    As for brakes - there's not too much difference between 11.75 and 12.19" wheels other than cost being higher on the 11.75 setup (new bracket), and about half a pound less for the scalloped rotors, about 0.8-0.9 lbs less for drilled/non-drilled rotors.

    So can STX use scalloped rotors? I know some classes had them banned. For scalloped rotors and something smaller than a Superlite for the caliper (still 4 piston, still track worthy), it'd be roughly 11 lbs per corner. That's less than just a stock S13 rotor by itself. Drilled rotors will add about 2 lbs or so to that, so as much as an S13 ABS rotor.
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    • #3
      For the front arms, the bushing type has to stay the same, so I'd need to keep a rubber or poly bushing at the inside, although I'd be allowed to run a longer LCA. It doesn't state anything about the ball joint height, though the advisory indicates that the ball joint is part of the LCA which is specifically replacable. I wonder how much you could "get away with" in that area, although a longer LCA alone might help roll center and camber gain enough to be worth it.

      I think there was a restriction on how much rotor area could be missing, so I think scalloped is out. For pistons, it's as least as many as stock and as much area or more.

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      • #4
        If there's enough people interested I could look into an 11.75" setup, but with a new bracket I'd need quite a few to make it where the machine shop will bother.

        The 12.19 stuff would be a little bit more expensive than the normal 12.19 kit, as for wheel spoke clearance I'd probably space the rotor inboard (or the caliper could come outboard, to the same location as Z32 calipers sit). So 13 lbs for a 12.19 x 0.81 drilled setup.

        I still think a 12.19 scalloped setup would have more surface area than a stock rotor though. Stock rotors are TINY.
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        • #5
          I don't see the car being competitive in either class. It's either down on power or too heavy. But with the allowance to run wider wheels/tires in STX, at least new people won't be bumped to DSP and get the tire sticker shock and scared off.

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          • #6
            It did really well in STS where I think it's at more of a disadvantage vs. the EF Civic hatches IMO than against similar cars in STX that are a bit heavier with the same drivetrain on average.
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            • #7
              AFAIK You're not allowed to move the ball joint's center of rotation WRT the upright, but you can lengthen the arm. IE no roll center mods, but yes camber mods.

              I say this because STR S2000's are not allowed to shim their ball joints down.
              Originally posted by Jason M
              I have no chance to win without the Giken...

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              • #8
                Originally posted by cdlong View Post
                I don't see the car being competitive in either class. It's either down on power or too heavy. But with the allowance to run wider wheels/tires in STX, at least new people won't be bumped to DSP and get the tire sticker shock and scared off.
                Consider that STC was faster than STX at Nationals this year (among many, IIRC) and it's a no-brainer that the car is going to fare better in STX. On top of that, STX just looks like more fun!

                It'll be easy enough to test the waters since the STC car is most of the way there. Unfortunately it's the "wrong car" until I can do a non-HICAS conversion to it (new subframe and steering) but it should be a good indicator. I really want to build up an S14, though, as there's less issues with tire clearance, the rear subframe is better, and the intake manifold is less restrictive (or I need to fix something with the secondaries on the S13).

                Considering our STC car was down on power the year we ran it, on top of it having a host of handling issues dealing with HICAS working/ not working, I honestly think a well built and tuned 240 has a chance in STX.

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                • #9
                  Originally posted by josh18_2k View Post
                  AFAIK You're not allowed to move the ball joint's center of rotation WRT the upright, but you can lengthen the arm. IE no roll center mods, but yes camber mods.

                  I say this because STR S2000's are not allowed to shim their ball joints down.
                  If you modify the arm, you can do so in any way you see fit so you can adjust the roll center. The problem is, you can't do anything to the steering arm so you get weird bump steer issues. You have to lengthen the arm quite a bit, don't you? Is there enough range of adjustment in the tie rod to match the longer control arm?

                  What makes you think you can't adjust the ball joint on an S2000? There was a clarification a year or so ago that said the ball joint is part of the arm (unless it's mounted in the upright) and can be modified when the camber kit allowance is used, hence the quote from Fastrack in the original post.

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                  • #10
                    Originally posted by AceInHole View Post
                    Consider that STC was faster than STX at Nationals this year (among many, IIRC) and it's a no-brainer that the car is going to fare better in STX. On top of that, STX just looks like more fun!
                    I noticed that, but is that consistent? Pax is softer in STC, isn't it generally a hair slower? .824 to .827 is basically a wash anyway.

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                    • #11
                      Originally posted by AceInHole View Post
                      Consider that STC was faster than STX at Nationals this year (among many, IIRC) and it's a no-brainer that the car is going to fare better in STX. On top of that, STX just looks like more fun!

                      It'll be easy enough to test the waters since the STC car is most of the way there. Unfortunately it's the "wrong car" until I can do a non-HICAS conversion to it (new subframe and steering) but it should be a good indicator. I really want to build up an S14, though, as there's less issues with tire clearance, the rear subframe is better, and the intake manifold is less restrictive (or I need to fix something with the secondaries on the S13).

                      Considering our STC car was down on power the year we ran it, on top of it having a host of handling issues dealing with HICAS working/ not working, I honestly think a well built and tuned 240 has a chance in STX.
                      Don't you think S13 KA cams will make more power than S14 KA cams with an S14 intake mani?
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                      • #12
                        It would (hopefully, that's my plan for my DSP car) but it's not legal for the class. No intake modifications past the TB in ST (any intake allowed in SP). No cam cam mods allowed in either.

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                        • #13
                          Maybe I didn't phrase that well. I'm saying the S13 as it stands will make more power due to the cams than the S14 as it stands due to its weak cams despite its better intake mani.

                          The S14 is likely faster overall due to better suspension geometry though.
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                          DefSport Koni Sleeve and Spring Perch Buy!!!
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                          • #14
                            Ahh. They were rated the same from the factory and the restrictions are both in areas you can't change so I'm not sure. Though my s13 felt more powerful than my s14 (not that that really means anything) and they certainly wouldn't have dropped the published power numbers when introducing the s14.

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                            • #15
                              The s13 we're running definitely doesn't feel a powerful as my original s14...
                              It may be a wash between the intake and cams, but I think ultimately the S14 will have a better power band at similar peak numbers, on top of other benefits (tire fitment and rear subframe).

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