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In detail: 5x120 rear, using MZ3 rear trailing arms.

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    In detail: 5x120 rear, using MZ3 rear trailing arms.

    First, and most importantly the parts list.

    Complete trailing arms, left and right.
    Brake rotors (same as e36 M3 rear)
    Brake calipers
    MZ3 halfshafts (much larger/beefier then the e30 unit)
    MZ3 diff output flanges (much larger bolt pattern then e30 units)


    Complete trailing arms



    MZ3 trailing arms are far superior to the e30 unit. The overall design is the same but they have added camber/tow bracing that makes them a much more solid design. A complete trailing arm should come with the arm itself, and the hub/wheel bearing still pressed in. Buying bare arms without the hub/bearing sucks. Alot of work for someone without the special tools to press them in.

    You will have to use the e30 trailing arm brake hardline. The locating tab on the brake backing plate is missing on the MZ3 backing plate. I choose to cut it off a set of e30 backing plates and tack weld it onto the MZ3 backing plate.

    While you have the arms off the car it would be smart to weld on the sway bar re-enforcement tabs. Turner, IE, etc sell them, or you can make them yourself.

    Brake rotors



    Brakes are a big upgrade with this conversion. The MZ3 rear disc brakes are 312x20mm vented units. The same rotor used by the e36 M3 in the rear. A e30 325i has puny 258x10mm solid rear discs! I'd suggest buying new, but the used ones I got from a 16k mi MZ3 were in very good shape.

    Brake calipers



    Calipers are standard issue single pistons, much the same as the stock e30 rear caliper in design. They are however much larger! I decided to disassemble, beam blast, paint, and rebuild mine. Rebuild kits are cheap, and not very difficult to do. Rebuilt units can be had for < $100. Got a pair from a 16k mi MZ3, but rebuilt them anyways.

    M-Roadster / Coupe rear halfshafts



    AFAIK these are unique to these cars. They are much larger in diameter then the e30 units. These list for ~$350 each new, and I had no luck finding rebuilt unit. Got good used ones from a 16k mi MZ3.

    M-Rodster / Coupe diff output flanges



    I think these are also unique to these cars, E28 output flanges can be used as well. That may be true but the E28 halfshafts are not! Different design. Get these used. The MZ3/E28 flanges will swap into a e30 diff. They just pull and push in.

    The rear suspension swap is pretty straight forward. Unbolt and remove everything related to the stock suspension and remove it. MZ3 arms bolt directly in with no modification. You CAN reuse your stock brake line if your car originally had ABS and rear disc's. It just needs to be bent up slightly to run down the arm and up to the caliper (rather then around the backside etc) Be very careful not to kink the line while you are bending it.

    As for the ABS sensor. You have 2 choices. Splice the e30 connector onto the MZ3 sensor, or install the e30 sensor with a spacer. Problem is the e30 sensor is much longer then the MZ3 and would bind on the pulse ring. To solve this problem I found a copper crush ring in the crush ring assortment that was the exact right internal diameter to fit snuggly on the sensor. I think it took 4 or maybe 5 of the crush rings stacked to make up the difference in the length. I installed them with a longer allen screw and my ABS works perfectly. I will double check the # of spacers and photograph it when I get a chance.

    The e30 ebrake cable will route through the back of the MZ3 trailing arm and connect to its native ebrake hardware perfectly. The MZ3 ebrake hardware is very similar to the e30, but much larger and beefier. Let me tell you.. I had brand new ebrake shoes on my e30 suspension, and I could drive with it locked without a problem. The MZ3 shoes LOCK the rear wheels. If you try to go anywhere you are out of luck.
    Tenured Automotive Service Professional - Avid BMW Enthusiast

    Vapor Honing & E30 ABS Pump Refurbishment Service
    https://mtechniqueabs.com/

    #2
    Some pictures added.
    Tenured Automotive Service Professional - Avid BMW Enthusiast

    Vapor Honing & E30 ABS Pump Refurbishment Service
    https://mtechniqueabs.com/

    Comment


      #3
      Dude, that looks really tough! Hope it works as well as you planned.
      L8R,
      Luke
      PS...check yer PM's

      Closing SOON!
      "LAST CHANCE FOR G.A.S." DEAL IS ON NOW

      Luke AT germanaudiospecialties DOT com or text 425-761-6450, or for quickest answers, call me at the shop 360-669-0398

      Thanks for 10 years of fun!

      Comment


        #4
        Jordan what are you gonna be running for a front set up??
        sigpic
        Wastedincome420@yahoo.com

        CURRENT STOCK LIST:
        00' e38 750iL HighLine=Highway Queen
        92' e30 318 vert=Aint going anywhere
        91' e34 535iM=Aint going anywhere
        91' e34 525iA=For parts
        92' e34 535iA=For parts

        Comment


          #5
          e36 M3 brakes, 315x28 Using SBI rotor spacers on e30 M3 strut assemblies.
          Tenured Automotive Service Professional - Avid BMW Enthusiast

          Vapor Honing & E30 ABS Pump Refurbishment Service
          https://mtechniqueabs.com/

          Comment


            #6
            damn you reply fast......

            Good luck and caint wait to see it finished
            sigpic
            Wastedincome420@yahoo.com

            CURRENT STOCK LIST:
            00' e38 750iL HighLine=Highway Queen
            92' e30 318 vert=Aint going anywhere
            91' e34 535iM=Aint going anywhere
            91' e34 525iA=For parts
            92' e34 535iA=For parts

            Comment


              #7
              Originally posted by Jordan
              e36 M3 brakes, 315x28 Using SBI rotor spacers on e30 M3 strut assemblies.
              With this set up will you run into any "wheel centering" issue's ??
              sigpic
              Wastedincome420@yahoo.com

              CURRENT STOCK LIST:
              00' e38 750iL HighLine=Highway Queen
              92' e30 318 vert=Aint going anywhere
              91' e34 535iM=Aint going anywhere
              91' e34 525iA=For parts
              92' e34 535iA=For parts

              Comment


                #8
                Originally posted by wastedincome420
                Originally posted by Jordan
                e36 M3 brakes, 315x28 Using SBI rotor spacers on e30 M3 strut assemblies.
                With this set up will you run into any "wheel centering" issue's ??
                No, because he is using e30 m3 suspension components. The brakes don't have any effect on caster.
                '91 318is
                sigpic

                Comment


                  #9
                  Originally posted by Brew
                  Originally posted by wastedincome420
                  Originally posted by Jordan
                  e36 M3 brakes, 315x28 Using SBI rotor spacers on e30 M3 strut assemblies.
                  With this set up will you run into any "wheel centering" issue's ??
                  No, because he is using e30 m3 suspension components. The brakes don't have any effect on caster.

                  I just want to make sure I got cause this sounds like the best way to go. Do you use a E30 or E36 M3 hub??

                  Last question I promise :roll:
                  sigpic
                  Wastedincome420@yahoo.com

                  CURRENT STOCK LIST:
                  00' e38 750iL HighLine=Highway Queen
                  92' e30 318 vert=Aint going anywhere
                  91' e34 535iM=Aint going anywhere
                  91' e34 525iA=For parts
                  92' e34 535iA=For parts

                  Comment


                    #10
                    Originally posted by wastedincome420
                    Originally posted by Brew
                    Originally posted by wastedincome420
                    Originally posted by Jordan
                    e36 M3 brakes, 315x28 Using SBI rotor spacers on e30 M3 strut assemblies.
                    With this set up will you run into any "wheel centering" issue's ??
                    No, because he is using e30 m3 suspension components. The brakes don't have any effect on caster.

                    I just want to make sure I got cause this sounds like the best way to go. Do you use a E30 or E36 M3 hub??

                    Last question I promise :roll:
                    lol, you aren't gonna do this Mark. :)

                    Comment


                      #11
                      stock e30 m3 wheel bearing/hub.
                      Tenured Automotive Service Professional - Avid BMW Enthusiast

                      Vapor Honing & E30 ABS Pump Refurbishment Service
                      https://mtechniqueabs.com/

                      Comment


                        #12
                        Originally posted by Beemerfanatik
                        [

                        lol, you aren't gonna do this Mark. :)



                        You'd be surprised what I gots brewing in mind......Another day or two and I'll $ 3-4k reading to dedicate to da E30 ;)


                        PS: Scott: I think I have convinced my self not to due the S38 project
                        sigpic
                        Wastedincome420@yahoo.com

                        CURRENT STOCK LIST:
                        00' e38 750iL HighLine=Highway Queen
                        92' e30 318 vert=Aint going anywhere
                        91' e34 535iM=Aint going anywhere
                        91' e34 525iA=For parts
                        92' e34 535iA=For parts

                        Comment


                          #13
                          What are you doing to address ABS? Disabling it or going to rewire your sensors? I tried to rewire but couldn't get it to work properly.

                          Comment


                            #14
                            No rewiring needed. No cutting of any wires etc. All sensors/wiring intact. My ABS is 100% functional. Tested it twice tonight. Works WELL.
                            Tenured Automotive Service Professional - Avid BMW Enthusiast

                            Vapor Honing & E30 ABS Pump Refurbishment Service
                            https://mtechniqueabs.com/

                            Comment


                              #15
                              I thought the MZ3 trailing arms had an abs sensor that was shorter than the E30 ones. I know the 318ti trailing arms are that way. I see you are infact using E30 M3 front struts so obviously those would be compatible.

                              Comment

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