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  • #31
    Originally posted by Ironhead View Post
    Hey dudes......

    I am trying to figure out a source for these thingys. (thanks Booker for the pics I "borrowed") They are used on the DTM trailing arms to allow a rod end to adjust for camber and toe without being unbolted and "turned".

    Does anyone know if they are a BMW Motorsport specific part, or a generic item used in other motorsport venues?

    Thanks!





    I have started mocking something up in CAD a few month back, but I haven't got an immediate need to correct my rear axle (tyre wear still acceptable), so it went on hold.
    If somebody can spec a rod end to be used I will keep working on this over winter.
    I just can't see myself doing the excentric bolt solution if it's such a PIA


    Goodbye M3, you served me well.

    Comment


    • #32
      You might try to send an e-mail to Muzzimotorsport.com and see if they have any.

      Comment


      • #33
        These are not a MS part, I had them made.

        They work well in a race car application, not sure if they would be an ideal solution
        in a street driven car. The design of the adjusters + rod ends may not hold up well
        to the dust, dirt and moisture of everyday driving.

        The only issues I have with these are that they quite heavy and were a PITA to
        integrate.

        Mike
        sigpic

        Comment


        • #34
          what I have done so far:





          Idea was to leave the internal joint of the trailing arm as is (with a spherical bearing maybe) and weld this on the outside pickup.

          Pink screw for camber ajustment, lilac for toe. I didn't spend too much time so the bolt length etc isn't really finished. If somebody can spec a rod end suitable I will try and keep working on it over winter. Doesn't need to be metric, I had a quick look and imperial roadends seem to have better load values than normal metric thread.


          Goodbye M3, you served me well.

          Comment


          • #35
            Uwe,
            Yours is VERY similar to the 1st Gen Grp A part.
            Its almost identical.

            I had a spare one from my BTCC car that I gave to Andrew Taylor years ago to get copied by his machinist,,, which I never saw again. So now the only ones I have are in the car.

            You are definitely on the right track.

            Cheers
            jimmy
            jimmy p.
            87 E30 M3 Prodrive British Touring Car
            88 E30 M3 Zinnoberot - Street
            88 E30 M3 Lachsilber - Race (#98 SCCA SPU)
            92 E30 M Technic Cabrio - S14 POWERED!
            98 318Ti M44, Base - Morea Green
            04 Ford F350 - V10

            Comment


            • #36
              Originally posted by jimmy p. View Post
              Uwe,
              Yours is VERY similar to the 1st Gen Grp A part.
              Its almost identical.

              I had a spare one from my BTCC car that I gave to Andrew Taylor years ago to get copied by his machinist,,, which I never saw again. So now the only ones I have are in the car.

              You are definitely on the right track.

              Cheers
              jimmy
              to be honest I "developed" this from looking at Grp A pictures......
              I am just not sure what rod end to use. And of course I want to make something which can be machined without costing a fortune. I also thought about using rubber dust boots. Any thoughts? My car isn't seeing so much road anymore


              Goodbye M3, you served me well.

              Comment


              • #37
                Originally posted by UweM3 View Post
                to be honest I "developed" this from looking at Grp A pictures......
                I am just not sure what rod end to use. And of course I want to make something which can be machined without costing a fortune. I also thought about using rubber dust boots. Any thoughts? My car isn't seeing so much road anymore

                I was planning the same thing Uwe. I don't really see where the rubber dust boots could hurt anything..... My car is driven on the road from time to time, but not enough that I am hugely worried about the rod ends wearing out.....

                What made me want to go this way, was corner weighing my car with urethane bushings. They really have a great deal of friction. I could put the car on the scales and get a certain reading.....bounce it and get a completely different reading.....etc. The only explanation is friction in the pivot points.

                I eventually want to do some sort of front control arm setup also, that uses rod ends. You can buy the ready made "DTM" setup from Germany, but the price seems a little unjustifiable. I also don't want to use metric rod ends. I know they are available, but in standard thread there are many, many more options. At least in the USA.

                Comment


                • #38
                  Uwe, as we discussed previously, pretty much along my same line of thought, except I cannot draw, free hand or on the computer.

                  If you build it, I will buy some. Then I can put jimmy's control arm bearings to good use in the inner arm. You might need to bug him to get some more made up.

                  If I can help, please let me know.

                  Thanks,
                  Mike

                  Comment


                  • #39
                    Originally posted by empty View Post
                    Uwe, as we discussed previously, pretty much along my same line of thought, except I cannot draw, free hand or on the computer.

                    If you build it, I will buy some. Then I can put jimmy's control arm bearings to good use in the inner arm. You might need to bug him to get some more made up.

                    If I can help, please let me know.

                    Thanks,
                    Mike
                    definately interessted to get some control arm bearings. Or the details and I get them made. I already have two spare trailing arms, just looking to get a subframe and I ca start making weld jigs.
                    I am a little bit reluctant to sell this. I know I will run it on my own car, but the responsibility if something fails on such an important part is quite huge.
                    Another point I have to investigate is the need to keep the inside pickup floating? If you adjust toe the distance between the pivot points will change, so is there a need to keep the inside floating? (and will it work safely?)

                    Ironhead, your finndings with the cornerweighing is excatly the reason I don't want to go the excentric bolt solution. It does move the pivots completely out of alignment.


                    Goodbye M3, you served me well.

                    Comment


                    • #40
                      Originally posted by UweM3 View Post
                      definately interessted to get some control arm bearings. Or the details and I get them made. I already have two spare trailing arms, just looking to get a subframe and I ca start making weld jigs.
                      I am a little bit reluctant to sell this. I know I will run it on my own car, but the responsibility if something fails on such an important part is quite huge.
                      Another point I have to investigate is the need to keep the inside pickup floating? If you adjust toe the distance between the pivot points will change, so is there a need to keep the inside floating? (and will it work safely?)

                      Ironhead, your finndings with the cornerweighing is excatly the reason I don't want to go the excentric bolt solution. It does move the pivots completely out of alignment.
                      Too bad you are in the UK. I have the subframe, but not yet the trailing arms....

                      It is funny. I know exactly what you mean about not wanting to sell them...neither would I. But I have the feeling that all of us are going to wind up doing one-off setups and re-inventing the wheel....making weld jigs that are going to be used once.... Too bad there is no practical way to do it "community" fashion.

                      I talked to the guy who did the work for Gustave with his custom rear trailing arms. We talked at length...very knowledgable guy. He has the jigs ready to go. But then it got kind of weird.....he said he wants to get out of doing "custom" work and sell only stock products. He told me I had to buy some of his "off the shelf" products before he would work on custom trailing arms...... So needless to say that was a dead end. Too bad though, he clearly has this stuff dialed....

                      I am currently at a loss as to who I will find to to the actual fabrication.

                      Comment


                      • #41
                        Uwe,

                        I love the drop-shadow. You just couldn't help yourself, could you!?
                        Anders

                        "Objects in mirror are losing..."

                        Comment


                        • #42
                          Looks great Uwe!


                          Disclaimer: Remember, I know absolutely nothing, but it doesn't prevent me from having an opinion or suggestion. :

                          Comment


                          • #43
                            "Ironhead, your finndings with the cornerweighing is excatly the reason I don't want to go the excentric bolt solution. It does move the pivots completely out of alignment."

                            Of course just replaceing the bushings with bearings will solve the alignment/binding issues. The fact is that adjusting the eccentric type is a pain in comparison and that they do slip from time to time. It is often recommended to tac them weld them in position when "correct" geometry is established. Also I can't help but imagine that the overall strength of the trailing arm pickup is weakened buy both slotting and putting the the bolt further away from the subframe. Not an issue for most, but in an extreme....

                            Also referencing Jakes dtm tour I noticed 2 things. Firstly there is another nut on the toe portion of the assembly- presumably a lock nut. I'm a little confused as to how this all goes together. Looking at Uwe's drawing I'm guessing that the blue part acts as a turnbuckle threading into the orange block.

                            Secondly I thought in interesting that the trailing arm bolt/bracket is flipped 90 deg allowing for roll center adjustments. This leaves all the pivoting to be done with the ball spherical bearing?

                            Fun thread!
                            Last edited by peteinjapan; 08-22-2008, 11:45 AM.

                            Comment


                            • #44
                              The trailing arm bearings I had came influenced greatly by the "inner" Grp A setup.
                              Its very similar.
                              We had to make some changes to accommodate commercially available bearings that would fit the dimensions.

                              Uwe's proposed setup mimics the OUTER arms of the 1st Gen Grp A trailing arms.
                              The two when combined work really well together for free movement and adjustability.
                              Uwe you only need to make the outer one adjustable as you have.
                              The inner can stay fixed (non adjustable) as long as it can pivot on a spherical.

                              The rear rod ends on the Grp A setup I "believe" had 12mm shanks / bores.
                              I have spares for mine at home, I can check when I get home (in Dec).
                              I just cannot remember if those were metric rod ends or SAE.

                              I have the luxury of having the BTCC car there sitting next to the silver one to compare and draw ideas from (or copy the occasional part).

                              I agree 100% with Uwe & Ironhead on 3 things.
                              1) Making and selling this stuff is scary for the private individual.
                              Geoff A. & I had plans to start knocking off all kinds of stuff from my Grp A car,,, but time and reluctance to get into the liability of selling race car things made us backaway and just do it for ourselves. We know we will never sue each other.

                              2) Once you feel a heim jointed suspension move without shock resistance,,, you will never want to go back to bushings of any kind.
                              I ran all mine front & rear through the full range of motion mocked up with no shocks and its a different world.

                              3) Because of fear of the possible liability,,, I am "sure" there will be numerous of us who have the will, desire and ability to make these parts will all go down the same path,,, and be developing very small "personal" batches of the same parts.
                              Definitely not the most efficient or best way to do it.

                              Good plans there Uwe.
                              I hope you get it together.
                              Cheers
                              jimmy p.
                              Last edited by jimmy p.; 08-22-2008, 11:37 AM.
                              jimmy p.
                              87 E30 M3 Prodrive British Touring Car
                              88 E30 M3 Zinnoberot - Street
                              88 E30 M3 Lachsilber - Race (#98 SCCA SPU)
                              92 E30 M Technic Cabrio - S14 POWERED!
                              98 318Ti M44, Base - Morea Green
                              04 Ford F350 - V10

                              Comment


                              • #45
                                I am watching this thread with great interest. Having an M-coupe i am interested in a solution to the rear trailing arms and i'm sure there might be quite a few other m-coupe/roadster owners who would be interested in such a setup.

                                Perhaps the guy who did Gustave's work would be more amiable if he knew he could make a run of 10 sets?

                                also, in lieu of using Gustave's guy, i might know someone who would be willing to do this kind of fabrication work but i'd have to talk to him and see... would we be talking modification of existing trailing arms using machined critical bits?

                                thanks,
                                Rukman

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