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  • I've got many many track days in a mostly stock E36 M3 under my belt, and I honestly felt like my S13 with an S14 subframe put power down just as easily. I always struggled to get the car to turn in on initial turn-in, but on power it was a dream - very easy to control, no surprises, and it maintained neutral behavior.
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    • Sorry to revive an old thread.

      I'm curious to if anyone has used this gktech anti-squat reduction weld in kit? Instead of swaping in the S14 subframe? From what I understand that was really the only reason for S13s to swap in the S14 subframe.
      https://us.gktech.com/s13-240sx-r32-...on-weld-in-kit

      From what I gather from the previous posts to get the ideal anti-squat, either use the above mention weld in kit, or swap in the S14 subframe, then use the gktech rear kuckles to increase the anti-squat to the ideal 120% range? you to run stiff rear springs? 8k/6k?
      https://us.gktech.com/240sx-skyline-...new-kinematics
      Or swap in the S14 subframe and use the SPL conversion bushing kit and raise the subframe closer to the chassis increasing the anti-sqanti-squa
      https://www.splparts.com/spl-pro-sol...-bushings-s13/

      Or don't bother correcting the anti-squat keep the S13 subframe and run really soft rear springs like mentioned in the previous post 8k/5k.

      Which option produces the better result?
      Last edited by quiets13guy; 07-24-2020, 11:35 PM.

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      • Originally posted by quiets13guy View Post
        Sorry to revive an old thread.

        I'm curious to if anyone has used this gktech anti-squat reduction weld in kit? Instead of swaping in the S14 subframe? From what I understand that was really the only reason for S13s to swap in the S14 subframe.
        https://us.gktech.com/s13-240sx-r32-...on-weld-in-kit

        From what I gather from the previous posts to get the ideal anti-squat, either use the above mention weld in kit, or swap in the S14 subframe, then use the gktech rear kuckles to increase the anti-squat to the ideal 120% range? you to run stiff rear springs? 8k/6k?
        https://us.gktech.com/240sx-skyline-...new-kinematics
        Or swap in the S14 subframe and use the SPL conversion bushing kit and raise the subframe closer to the chassis increasing the anti-sqanti-squa
        https://www.splparts.com/spl-pro-sol...-bushings-s13/

        Or don't bother correcting the anti-squat keep the S13 subframe and run really soft rear springs like mentioned in the previous post 8k/5k.

        Which option produces the better result?
        I'm actually working on trying this out on my S13, I'll try to remember to update when I get it done in the next few weeks.

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        • Originally posted by quiets13guy View Post
          Sorry to revive an old thread.

          ...

          Or don't bother correcting the anti-squat keep the S13 subframe and run really soft rear springs like mentioned in the previous post 8k/5k.

          Which option produces the better result?
          I'm glad you posted this. And i'm glad NRR is back online! I've wondered why so many ppl either run less rear bar or bother swap S14 subframe for anti squat revising when the easier solution is to just run a softer spring in the rear.

          S14 subframe swap makes sense, but running less or no rear sway bar almost doesn't make sense to me. Why mess with roll stiffness to correct a squat/dive stiffness issue?



          Originally posted by Wookie384 View Post

          I'm actually working on trying this out on my S13, I'll try to remember to update when I get it done in the next few weeks.
          Would love to hear your feedback. What are the spring rates you are running, F 8k / R 5k ?

          I am considering running 7k front 4k rear and hoping the rear isn't too soft. I'm looking for maximum mechanical grip out of a drift car. Not a high speed car (sub 65 mph car speed)

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          • A softer rear spring affects your handling balance when going around corners (with same stiffness front springs), then will make your suspension act much stiffer when on power.

            You've got to tune everything together in your suspension.


            I'll say I really liked going S13 to S14 rear subframe, as the car immediately gained a lot more grip on mid-corner and corner exit when getting on the power. I could go up in rear (and front) rate and keep the same handling balance, and the car just hooked up better under power.

            I think even the S15 took out a slight bit more anti-squat, but have never been able to confirm that. Seems Nissan felt the benefits outweighed the negatives, and with a really stiffly sprung car like a modded S-chassis, less anti-squat seems to be better all around.
            '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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            • Originally posted by Def View Post
              A softer rear spring affects your handling balance when going around corners (with same stiffness front springs), then will make your suspension act much stiffer when on power.

              You've got to tune everything together in your suspension.
              Makes sense. What about hypothetical softer rear spring to allow more squat, and a stiffer rear anti roll bar to compensate and stiffen the roll stiffness in the rear?

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              • Anti-squat force doesn't behave the same as a stiffer spring though. It's a direct force down based on the anti-squat percentage. So as you apply power, you're changing the force share between anti-squat and the spring/damper.

                So it's still not apples to apples.
                '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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                • So... do I keep my s13 rear subframe or swap in the s14 rear subframe that I have sitting waiting to go in?

                  I’m as confused as ever.
                  1990 240sx - Aristo 2JZGTE, R154, GT37, Defsport Wilwood kit, KTS coilovers - daily driver
                  1991 civic si - B18C5 / toda / ATS / hytech - autox
                  2001 integra type R - Greddy td05-18g - garage queen

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                  • Originally posted by Black R View Post
                    So... do I keep my s13 rear subframe or swap in the s14 rear subframe that I have sitting waiting to go in?

                    I’m as confused as ever.
                    Depends on your ride height, what suspension you're running, and how you want the car to perform. You can also just modify your LCA pickup to be in the same position as S14 and call it a day...
                    Support innovation, buy from companies that design their own parts!

                    Friends don't let friends buy knock-offs.

                    Suspension before power.

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                    • Originally posted by PoorMans180SX View Post

                      Depends on your ride height, what suspension you're running, and how you want the car to perform. You can also just modify your LCA pickup to be in the same position as S14 and call it a day...
                      That's what I did.

                      When I was racing with ChumpCar I wanted the S14 geometry, but didn't want to take the points for a subframe swap. I measured the two subframes and tried to replicate the RCA angle by cutting/welding (free in ChumpCar).

                      Viewing somewhat flat looking towards the back of the RCA on the S13 subframe:



                      Compared to the mostly flat LCA on the S14:



                      This was what I came up with in 2014, essentially what the GKTech kit does now.


                      The front is nice and strong, but the rear I cut/rotated and did not brace enough. After years of racing (around 250 hours) at our last race the rear mount broke.

                      From driving the car before/after, there was a definite improvement in ability to put power down, especially over bumpy surfaces. My limited understanding of anti-squat in the S13 is that a lot of the load transfers directly to the rear through the path of the control arm, kind of shortcutting the springs. By having the load transfer so directly, it seems to act like the rear suspension is much stiffer on power and makes for more power on oversteer. Now that we aren't running with ChumpCar anymore.. we are swapping out the modified S13 subframe for an S14 one. Also not taking any chances and welded in the reinforcement kit from GKTech.

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                      • I ended up using the GKtech brackets.

                        Support innovation, buy from companies that design their own parts!

                        Friends don't let friends buy knock-offs.

                        Suspension before power.

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                        • Originally posted by PoorMans180SX View Post
                          I ended up using the GKtech brackets.

                          Nice how did they work out?

                          Also, I mentioned our subframe broke up above, this was a fun video I made from the race where it broke (at the very end of the video you can see how it looked when it broke).

                          Blue Bayou Youtube Channel
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                          • Thank you for this post. I just came across this forum from zilvia lol. Just welded the gk teck braces and anti squat mod. Wasn't sure what it was going to do.

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                            • Any update on the gktech brackets? does it feel like an s14 subframe? does it fix the antisquat? considering the price difference between sourcing a s14 subframe and the gktech brackets it's something I'm seriously considering.

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