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  • #61
    Anybody ever start a thread like this but for the urs4/6
    chassis. It would be cool to hear about some track day
    specs for other models.

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    • #62
      Thuppu is your man there - he's done some custom parts to get the geometry sorted.
      Cheers'en, AndyC
      1994 ABY Coupe - Projekt Alpinweiss

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      • #63
        Update from the weekend's track time:

        The car is still very stable and neutral (more so than a fast road setup B4 sedan) and now only has a touch of understeer under power and a nice hooked-up feeling on neutral throttle mid corner.

        The rear camber is still too high and the rear spring rate a little low, robbing some adjustability but what it does do is carry decent speed through the corners and I was on the power very early, meaning corner exit is very good with the line opening out a touch at WOT in 3rd followed by good grip when reducing the steering angle as the corner unfolds. Stability under braking is excellent, even with the toe out at the rear and steering weight is good with a small amount of extra feel over stock.

        The front is now as extreme as I'd want and the rear either needs more spring rate and roll centre or less camber to bring back some fun and adjustability.

        It's still a slow in fast out car but more corner speed and more stability on exit have improved the overall lap time if not the slippy slidey grin factor it had as standard.

        Plans for the future depend on springs & damper choice but on the current setup, I know what I'm going to settle on for a combined setup.

        On my own I was seeing 1m22/3s lap times from the video footage of the back of my head . That compares to 1m30s a few years ago on raod tyres, with standard turbo and standard suspension.
        Last edited by Rusty; 18 October 2015, 22:59.
        Cheers'en, AndyC
        1994 ABY Coupe - Projekt Alpinweiss

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        • #64
          Once I have the new transmission mounts, I'm going to pull the subframe to realign the bushes, as the updated design twisted when fitting, due to the gearbox mounts not being loosened and so no extra castor was achieved. Then it's time to finish this little project. I have decided upon the following settings:

          Front
          • 2.3-2.5 Deg Camber
          • 4.0-4.5 Deg Castor
          • 0.0-0.5mm toe in


          Rear
          • 1.0-1.2 Deg camber
          • 0.5-1.0mm toe out


          The range is because the values achievable are dependent on which method I choose to use to achieve the settings. I am looking for maximum reliability and am not keen on camber bolts on the front, having had the M14 bolts loosen in the past at the 'ring

          This should dial out most of the stability, that I found to be a little too sanitised on track, while maintaining the improving steering weight and front grip.

          These settings may change as/when I go to a coilover setup and can chose spring rates to dial out the understeer, rather than using a massive rear bar. A coilover setup would also allow me to adjust the roll centre balance front to rear.

          Other than the castor, all these settings are achievable on a stock car, so anyone can try them out without the need to spend £00s on new parts. Max stock castor is about 2.5 deg. to achieve this, you need to rotate the balljoints as far forwards as possible on the slotted holes.
          Cheers'en, AndyC
          1994 ABY Coupe - Projekt Alpinweiss

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          • #65
            Originally posted by Rusty View Post
            Once I have the new transmission mounts, I'm going to pull the subframe to realign the bushes, as the updated design twisted when fitting, due to the gearbox mounts not being loosened and so no extra castor was achieved. Then it's time to finish this little project. I have decided upon the following settings:

            Front
            • 2.3-2.5 Deg Camber
            • 4.0-4.5 Deg Castor
            • 0.0-0.5mm toe in


            Rear
            • 1.0-1.2 Deg camber
            • 0.5-1.0mm toe out


            The range is because the values achievable are dependent on which method I choose to use to achieve the settings. I am looking for maximum reliability and am not keen on camber bolts on the front, having had the M14 bolts loosen in the past at the 'ring

            This should dial out most of the stability, that I found to be a little too sanitised on track, while maintaining the improving steering weight and front grip.

            These settings may change as/when I go to a coilover setup and can chose spring rates to dial out the understeer, rather than using a massive rear bar. A coilover setup would also allow me to adjust the roll centre balance front to rear.

            Other than the castor, all these settings are achievable on a stock car, so anyone can try them out without the need to spend £00s on new parts. Max stock castor is about 2.5 deg. to achieve this, you need to rotate the balljoints as far forwards as possible on the slotted holes.
            What do you use to measure toe, camber and importantly caster? I have kit to do tow and camber but caster looks like it will make my head hurt.

            Sent from my LG-H955 using Tapatalk

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            • #66
              I get it done at a local motorsport place that has a full lazer alignment setup.
              Cheers'en, AndyC
              1994 ABY Coupe - Projekt Alpinweiss

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              • #67
                That explains it. None really about here.

                Sent from my LG-H955 using Tapatalk

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                • #68
                  Any garage with a lazer alignment setup can do it, it's just getting the ramp for an hour or two that's the issue. Anywhere that does race cars will be able to help I'm sure.
                  Cheers'en, AndyC
                  1994 ABY Coupe - Projekt Alpinweiss

                  Comment


                  • #69
                    Originally posted by Rusty View Post
                    Any garage with a lazer alignment setup can do it, it's just getting the ramp for an hour or two that's the issue. Anywhere that does race cars will be able to help I'm sure.
                    The problem is the Muppets that use the kit. And for health and safety your not allowed in the workshop bs.

                    Sent from my LG-H955 using Tapatalk

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                    • #70
                      Originally posted by diesel des View Post
                      The problem is the Muppets that use the kit. And for health and safety your not allowed in the workshop bs.

                      Sent from my LG-H955 using Tapatalk
                      i know the feeling!!

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