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    Understeer!!

    So My car is currently suffering from understeering during autoX.
    Current setup is 15x8 wheels with 225/45/15 hankook rs3
    Bilstein sport struts with IE 3 springs and offset CA bushings and other poly bushings.

    I do not want to buy camber plates yet as i am planning to go to full GC setup once I save up the money next season. So I will not have to purchase 2 sets of camber plates.

    I was wondering will a stiffer front sway bar and a strut bar help with understeer. i figured it would cut down on body roll and keep camber changes under check a little.
    Currently with IE3 it seems front is softer than rear.

    AutoCross Photos!!https://picasaweb.google.com/eugenes18t

    #2
    The alignment has to be pretty hardcore on these to eliminate understeer. Sorry to say in this case man.. When I ran my daily I just planned on buying a new pair of tires every 6mo! Back then it was 195/14 Azenis 215's on a GTi! :)

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      #3
      well the car is not daily most driving the car sees is to and from the track. What sort of aligment are we speaking of?
      Are you talking about camber or toe?
      Would a front sway bar help? i figure it would cause less positive camber on hard turns.

      AutoCross Photos!!https://picasaweb.google.com/eugenes18t

      Comment


        #4
        What are your tire pressures?
        What is your alignment / camber like?

        Is it understeering in the corner entry/mid/ or exit?

        Stiffer front end may not help. You sure it's not you entering the corner(s) at too high of a speed for street tires etc?
        Mtech1 v8 build thread - https://www.r3vlimited.com/board/sho...d.php?t=413205



        OEM v8 manual chip or dme - https://www.r3vlimited.com/board/sho....php?p=4938827

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          #5
          MAin issue is understeer kicks in between the beginning and md of turn.
          Usually run tires between 35-38 demanding on the track. I know sidewall does not roll and that I am using all of the tire edge. I chalk my tires between runs to monitor the grip patch.
          Ofcourse under steer shows when i enter a turn at little too fast so the point is being able to increase the speed at which i enter the turn a little.

          AutoCross Photos!!https://picasaweb.google.com/eugenes18t

          Comment


            #6
            Get a tire temp gauge...you may just be at the limit of what current tire and config can do ?

            How much camber?
            Mtech1 v8 build thread - https://www.r3vlimited.com/board/sho...d.php?t=413205



            OEM v8 manual chip or dme - https://www.r3vlimited.com/board/sho....php?p=4938827

            Comment


              #7
              currently with no plates I am at about -2 of the top of my head.

              AutoCross Photos!!https://picasaweb.google.com/eugenes18t

              Comment


                #8
                Stiffer up front will help with corner entry understeer. It may increase mid-corner to exit understeer.

                The most effective solution is a little bit more brake.

                Edit: More camber will improve mid corner performance, but it may actually *worsen* corner entry.
                Last edited by nrubenstein; 04-26-2011, 02:40 PM.
                2006 GMC Sierra 2500HD 4WD LBZ/Allison
                2002 BMW M3 Alpinweiß/Black
                1999 323i GTS2 Alpinweiß
                1995 M3 Dakargelb/Black
                - S50B32/S6S420G/3.91
                1990 325is Brilliantrot/Tan
                1989 M3 Alpinweiß/Black

                Hers: 1996 Porsche 911 Turbo Black/Black
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                Comment


                  #9
                  Add front toe out,it'll help drag the front into the turn(fake ackerman,which works better than it should).Try that before going stiffer.
                  If its not street driven much you can run lots of toe if needed.

                  Comment


                    #10
                    Yeah i have been thinking of adding a little toe for turn in. Will have to play with that was worried about stability on the freeway on the way to events as I have to drive about 80 miles to the event. But right now my toe is about 0.15 so a little might help

                    AutoCross Photos!!https://picasaweb.google.com/eugenes18t

                    Comment


                      #11
                      Generally adding stiffness reduces grip,assuming you can get enough camber to work with the roll.If you only have -2 camber you most likley need to stiffen the front to keep the contact patch happy.
                      Since I do my own alignments I work with measurements not degrees or angles,I'd run 1/4" total toe out without hesitation.

                      Sway bars are a great tuning tool-used in moderation imho.Big mondo bars do more harm than good in my experience,my last 2 summer time track only cars were tuned barless and fast/easy to drive(I haven't used bars on my ice race cars for years,totally different though).

                      Comment


                        #12
                        A stiffer front sway ins't going to help with early corner understeer. More front camber, zero to a bit of front toe out, or a larger rear sway will help. As will taking weight out of the trunk (like all of the tar).

                        With IE3 springs a good sway setup wout ble a 22/199mm sway set, withthe rear bar set full, or almost full, soft.
                        The car makes it possible, but the driver makes it happen.
                        Jim Levie, Huntsville, AL

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                          #13
                          I've got my car @ 1/8" toe out each side in the front.. it's a drift machine! :p I've always ran my cars @ -0- toe and I realized trying the extreme would be fun and a definite learning experience. Mine is HR race, Bilsteins, -4f (plates) & -2r camber..
                          I run Time Trials and I was SLOWER w. this toe setting so obviously it was fun but not fast. I'm thinking until I get Coils and Weld-in RTABS 1/8" total out in the front is probably going to be best.

                          Comment


                            #14
                            so looks like more toe might help, I am wondering if it is worth getting a after market front sway abr. I was looking at IE 25mm as the 25 mm is lighter than the 22 mm

                            AutoCross Photos!!https://picasaweb.google.com/eugenes18t

                            Comment


                              #15
                              I would save the money and use cabrio front bar and put money towards camber plates or coilovers....
                              Mtech1 v8 build thread - https://www.r3vlimited.com/board/sho...d.php?t=413205



                              OEM v8 manual chip or dme - https://www.r3vlimited.com/board/sho....php?p=4938827

                              Comment

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