DIY alignment

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  • mazur
    Mod Crazy
    • Jan 2006
    • 731

    #1

    DIY alignment

    For $25...:)

    I've been researching DIY alignments for past couple days and today decided to rig up a "smart strings" type contraption.

    Parts:
    -2x 8' aluminum C "tube" (imagine a square missing one wall)
    -3' aluminum flat bar.

    Basically I just cut off one foot off each C tube and cut them in half. To these I attached pieces of flat bar (which I had cut into 4 pieces). This part would be made to rest on the ends of the C tubes and be positioned however desired.

    Then I just marked the exact center of each piece and mounted to exact center of rear and front of the car via painters tape on top of the bumpers(which is stupid easy with the kidney grills and rear roundel). Then proceded to put on the fishing line.

    This is a very simple, but effective device. The most important thing is EXACT MEASUREMENTS.
    --------------------------------------------------------------------

    **Before alignment I had done a corner balance which really screwed up the alignment (ex. 100#'s was shifted away from FL corner and added to the right!) Plus, my car has always pulled pretty hard to the right with steering wheel off-center**

    With my mom sitting in the car (she weighs the same as I), I first measured the difference of camber from right to left wheel. To do this I used a straight edge standing against base of tire and measuring distance to it from top lip of the wheel. Camber was off by .5'', so I just increased the side that had more positive camber. *Will need to go to alignment rack or buy camber measuring tool to get actual measurement in degrees*

    Roll car back and forth and bounce on it to settle the suspension and redo measurements to confirm.

    Next, you take the difference measured from center back and front of the wheels lip to the string and you will get your toe. It being +/- should be obvious...

    Before- L: +1/8'' R:+1/16'' (right was a lot more positive before adding negative camber)
    After- L:-1/16'' R:-1/16''
    (- is toe out, + is toe in)

    *suspension settled after each adjustment*

    Results: AWESOME!!! Car actually goes straight down the road and wheel centered. And can't believe how good it feels after a corner balance and alignment in the fast corners (60-80mph):crazy:

    Oh...here are some pics...lol

    And please don't use tape for the flat bar like I did unless you're sure they're square (90* angle with C tube piece) and using steel is preffered since it won't bend. Like aluminum.


    Last edited by mazur; 10-01-2007, 10:07 PM.
  • surebimmer
    E30 Modder
    • Jan 2004
    • 978

    #2
    Good work! I can use the alignment machine at work so I don't have to do this.

    Can you measure the hight of your car? from the bottom lip of the front and rear rim lip to the fender. Want to see your ride hight.

    thanks

    Comment

    • mazur
      Mod Crazy
      • Jan 2006
      • 731

      #3
      Originally posted by surebimmer
      Good work! I can use the alignment machine at work so I don't have to do this.

      Can you measure the hight of your car? from the bottom lip of the front and rear rim lip to the fender. Want to see your ride hight.

      thanks
      Yah, sure, I'll do it tommorrow. Are your wheels 16''? I think you're saying measure from bottom wheel lip up to the fender, correct?

      Comment

      • surebimmer
        E30 Modder
        • Jan 2004
        • 978

        #4
        That's correct.bottom lip of rim to lower point of fender. I also have 16,s.

        Comment

        • nando
          Moderator
          • Nov 2003
          • 34827

          #5
          Will need to go to alignment rack or buy camber measuring tool to get actual measurement in degrees
          no you don't. some basic trig can figure that out for you. You just need a slope and you can figure out how many degrees it is - if it's .5" over 2 feet (the approx height of an E30 wheel), that's ~0.02 degrees using the arctangent function, which you can even google for. http://www.google.com/search?sourcei...28%2e5%2f24%29

          to check just enter tan(0.02083032) and you get your original slope back - .25/24
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          • mazur
            Mod Crazy
            • Jan 2006
            • 731

            #6
            Originally posted by nando
            no you don't. some basic trig can figure that out for you. You just need a slope and you can figure out how many degrees it is - if it's .5" over 2 feet (the approx height of an E30 wheel), that's ~0.24 degrees using the arctangent function, which you can even google for. http://www.google.com/search?sourcei...%28%2e5%2f2%29

            to check just enter tan(0.244978663) and you get your original slope back - .25/2
            Your right...I actually was doing this several days ago and forgot about that approach...it was late last night.

            The straight edge stands on the ground against the tire so you'd have to get the difference from top lip measurement from bottom lip. Measuring the wheel lip to lip (will not be = to wheel size...my 16's are 18'' lip to lip) will get you your hypotnuse. So I'd use Sin^-1(distance from lip/actual wheel diameter).

            I'm not seeing how'd you use tangent. The angle of the wheel should be the hypotnuse, no?


            I knew school must be good for something

            Comment

            • nando
              Moderator
              • Nov 2003
              • 34827

              #7
              Originally posted by mazur
              Your right...I actually was doing this several days ago and forgot about that approach...it was late last night.

              The straight edge stands on the ground against the tire so you'd have to get the difference from top lip measurement from bottom lip. Measuring the wheel lip to lip (will not be = to wheel size...my 16's are 18'' lip to lip) will get you your hypotnuse. So I'd use Sin^-1(distance from lip/actual wheel diameter).

              I'm not seeing how'd you use tangent. The angle of the wheel should be the hypotnuse, no?


              I knew school must be good for something
              well you can use sine, cosine, or tangent depending on which two sides you have. since you know the height (adjacent side) and you have the .5" measurement (opposite side), you can use tangent (or arctangent actually, since we are looking for the angle and not the slope).
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              • surebimmer
                E30 Modder
                • Jan 2004
                • 978

                #8
                did you have time to measure your ride hight?

                Comment

                • mazur
                  Mod Crazy
                  • Jan 2006
                  • 731

                  #9
                  Originally posted by surebimmer
                  did you have time to measure your ride hight?
                  Oh shit. I'm sorry.

                  It's like 19.5'' in rear and about 21'' in front.

                  The rear sits slightly higher than the front.

                  Comment

                  • nando
                    Moderator
                    • Nov 2003
                    • 34827

                    #10
                    I just realized, google gives you the results in radians, not degrees. but you can use (or any calculator really) to convert it easily enough.

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