Announcement

Collapse
No announcement yet.

Question regarding Roll Center Spacers / Bump steer correction....

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Question regarding Roll Center Spacers / Bump steer correction....

    ...so I ordered a set of the 26mm RCS's from Massive a few years back and they work just fine and do the job but I have a question regarding overall geometry that I have not been able to find. I was forever using stock brakes and now that I am using a bigger rotor (330X28) in a brake kit, I have noticed that I have clearance issues with the control arm ball joint casting and the tie rod ball joint boot. This has come about as I was installing the kit. Is this likely due to the fact that I am running these roll center spacers? The brake kit manufacturer has NEVER noted one issue with clearance in this area and we have confirmed the rotors to be the correct p/n. Any insight would be greatly appreciated so that I can put this clearance issue to bed. Thanks in advance gents!

  • #2
    Yes. I would say that clearance issues is direct result if one is using roll centre spacers without offset compensation. It's simple geometry. Remove the spring and work the suspension and it becomes obvious.

    Most people don't notice it since it occurs so seldom. The problem only occurs when suspension is compressed quite a lot.

    I choose the roll centre spacers from http://www.millway.se/bilmodell/e30/...ock-m3e30.html since they have offset built in to them so you avoid this problem.
    Even with these there is close, there has been contact with the brake shield during track days.
    Click image for larger version

Name:	M3E30_M3E36broms_PFskiva_2.jpg
Views:	1
Size:	101.8 KB
ID:	844370

    Comment


    • #3
      Thank you....I am very suspect in that the roll center spacer is my issue. I will remove and report back. I am just barely touching the rotor but it is enough so that the boot would tear or melt in little to no time, rendering the ball joint exposed to dirt and heat. My suspension is sitting unloaded as is yours in the above picture and I am getting the boot just ever so slightly rubbing the rotor.

      Comment


      • #4
        Here is the interference....

        Comment


        • #5
          I cant see your picture...
          I had a similar problem with the bigger brake-disk and roll-center-spacer.
          As said above, its geometry...the spacer moves the control arm closer to the disk.
          I did two things, grinding off carefully a bit from the control arm ball joint casting (after thinking carefully...mainly the overstanding crude casting brow and leaving a polished surface), and replacing the steering arm rubber boot (which was actually grinded open by the disk) with a smaller one from a swaybar link. Did the trick for me...it was with a 15mm spacer and an E36M3 control arm however.
          The heat input is not that high...just make sure you dont stop with your disks glowing red...

          Thomas
          Last edited by TR-Spider; 05-28-2013, 09:25 AM.
          sigpic

          Comment


          • #6
            Roll center spacers removed... Now I have plenty of room.

            Comment


            • #7
              I was evaluating to buy roll center spacers a while back, and decided against it because of the change to the control arm position. I ended up going with a tie-rod only solution (from AKG). So far I've been happy with the result. FWIW.

              Comment


              • #8
                Selling those spacers? for a great deal?
                =)
                @slowprogress

                Comment


                • #9
                  Originally posted by JZM3 View Post
                  Selling those spacers? for a great deal?
                  =)
                  I will sell them shortly. They will be in the classifieds when I get some time. I have the spacers, hardware and the instruction sheet that came with them.

                  Comment


                  • #10
                    Originally posted by M-tinker View Post
                    I was evaluating to buy roll center spacers a while back, and decided against it because of the change to the control arm position. I ended up going with a tie-rod only solution (from AKG). So far I've been happy with the result. FWIW.
                    On the tie rod kit from AKG did you have to drill out the spindle or is the kit piece tapered like factory tie rods?

                    Looks like a better solution to me especially with larger brakes.


                    search word "bump" and found it on AKG's website
                    Photos

                    Comment


                    • #11
                      I cut off part of my dust cover on one side of my car. Definitely don't drive around with it rubbing it was screw up your rotor quicker than you can say it.
                      1987 325is - 185-195k
                      1988 M3 - 141k

                      Comment


                      • #12
                        Originally posted by autox320 View Post
                        On the tie rod kit from AKG did you have to drill out the spindle or is the kit piece tapered like factory tie rods?

                        Looks like a better solution to me especially with larger brakes.


                        search word "bump" and found it on AKG's website
                        I may be wrong, but when I imagine mounting such distance tubes (looking at angle in that pic) then there is still the same effect of moving closer to the Brakes, due to the angle between brake disk and control arm bolt,no? Just curious... Thomas
                        Last edited by TR-Spider; 05-29-2013, 01:50 AM.
                        sigpic

                        Comment


                        • #13
                          Originally posted by autox320 View Post
                          On the tie rod kit from AKG did you have to drill out the spindle or is the kit piece tapered like factory tie rods?

                          Looks like a better solution to me especially with larger brakes.


                          search word "bump" and found it on AKG's website
                          The kit piece is already tapered. No modification needed. I did find the other end that fits into the rack is a tight fit. It took some wrenching to get it in.

                          Here's a picture of the tie rod on my car.

                          Cheers.
                          Attached Files

                          Comment


                          • #14
                            Originally posted by M-tinker View Post
                            The kit piece is already tapered. No modification needed. I did find the other end that fits into the rack is a tight fit. It took some wrenching to get it in.

                            Here's a picture of the tie rod on my car.

                            Cheers.
                            Are those aftermarket larger discs? I think the guys are pointing out it would get closer. Nice piece of kit! I'd seen it on E36 but didn't know they had it for E30.
                            Photos

                            Comment


                            • #15
                              I have Lee's Massive Rally kit in the front. The bottom part of the backing plate was cut off when I was trying different brake setup. You can see the E36 control arm is right up against the rotor already, even in its stock location.

                              Comment

                              Working...
                              X