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E36 Rack swap, wide(-ish) tires, new parts...feels unsteady

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    E36 Rack swap, wide(-ish) tires, new parts...feels unsteady

    There are a few changes that I recently made to my '89 convertible that should have me on solid footing but the car feet unstable from about 30 MPH and up.

    I had never driven the car more than a mile or so and at low speed before doing the rack swap. The car has new tie rods, the e36 rack felt VERY tight, and the control arm ball joints seem to be tight.

    The car was wrecked and repaired before the rack swap. I am a bit frustrated that it is not symmetrical (I was told by the body shop that the frame was straight) and my camber is off by .3* from side to side. Camber is -1.8* and -2.1* up front.

    Wheels are 17x7.5 with 215/45 tires.

    Toe APPEARS to be slightly out after a tape measure alignment.

    I ordered camber plates to correct for the camber irregularity from side to side.

    Where would you start in steps to remediate to unsteady steering/tracking? The car feels very...darty under steering inputs or even when trying to track straight.

    So what would you recommend first? Alignment (check?) before the camber plate install? CABs? Control arms?

    I am at a bit of a loss.
    Patrick Henry

    1989 325iC build: http://www.r3vlimited.com/board/showthread.php?t=316880



    #2
    This could be a few things. First off, the rack will be stiff for a while and won't return to center as well until it's worn in a bit. This is normal. Don't forget the steering will be significantly quicker than it was, and that'll take some getting used to input-wise. Second, Your tires may be "tramming," or following bumps and cracks in the road. This depends both on the type of tire you have and the suspension setup. Third, I'd be surprised if that degree (so to speak) of camber difference made a huge, disconcerting difference in driving comfort. It obviously isn't bad to correct it, though. Toe out will make the car darty; how far out was it? Was the car toed out on one side or both? Did you measure with someone in the car?

    Also, where did you put the spacers for the rack? If they weren't placed above the rack, you're going to get a lot of bump steer. That will make the car very unhappy.

    Also, bad suspension bushings and/or bent control arms could do this as well, I don't know what any of that looks like.
    Interested in vintage cars? Ever thought about racing one? Info, photos, videos, and more can be found at www.michaelsvintageracing.com!

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      #3
      Toe was measured with the car empty. I have driven it and need to do a now measurement- it was out be a degree or so on both sides.

      I also never considered that it could be a tire balance issue but that would make it shake moreso than to be darty or to track weird.

      I installed the rack spacers both above and below- the total spacer was 1/2" and I used smaller 1/4" spacers split above and below the rack to split the difference.
      Patrick Henry

      1989 325iC build: http://www.r3vlimited.com/board/showthread.php?t=316880


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        #4
        I would put my money on toe out.

        If you have the camber plates, slap them on and get an alignment.

        When I installed my E36 rack, I had the same sort of darty steering feel and pretty much killed my new 225's by doing a terrible string alignment myself. They feathered and wore terribly on the inner edge. After a visit to get an alignment at an E30-fluent shop that understood I wanted to daily the car, but max out camber for autox, they made me a good compromise street setting that has stopped the abnormal wear.
        Originally posted by priapism
        My girl don't know shit, but she bakes a mean cupcake.
        Originally posted by shameson
        Usually it's best not to know how much money you have into your e30

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          #5
          Camber plates arrived earlier than expected. I'll be trying to install them this weekend.

          I will also be doing a front/rear swap of my current wheels and may try a loaner set of well-balanced (known good) stock wheels.
          Patrick Henry

          1989 325iC build: http://www.r3vlimited.com/board/showthread.php?t=316880


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            #6
            In my experience, camber plates set at anything more than about half way will exacerbate this feeling. I set mine for max camber on the track, though they are only a hex wrench width from maximum outward/straight up for street driving.
            Originally posted by kronus
            would be in depending on tip slant and tube size

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              #7
              Originally posted by agent View Post
              In my experience, camber plates set at anything more than about half way will exacerbate this feeling. I set mine for max camber on the track, though they are only a hex wrench width from maximum outward/straight up for street driving.
              My decision to pirchase camber plates was intended to equalize camber L&R to the lesser reading. I'd prefer to keep it to -1° to -1.25° if possible. This is a street car so comfort, drivability, predictability, and tire life are all considerations.

              If the frame was 100% straight and I did not have high negative camber readings (even for a mildly lowered car) I would skip the camber plates.
              Patrick Henry

              1989 325iC build: http://www.r3vlimited.com/board/showthread.php?t=316880


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