Materials to Maintain Your ZHP IIIII Hand Protection IIIII Tools to Maintain Your ZHP
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  1. #1
    Join Date
    Feb 2011
    Location
    Vancouver, Canada
    Posts
    3,588

    Exclamation She's got the big bouncing booty blues... (Subframe Material)

    And so the saga continues with ownership of BMW's wonderfully designed rear axle carrier panel that just can't quite hold the power of M. I guess owning a car that tries to kill itself with every drive out is a cool statement but we all know there is a much larger fault that most don't know about!

    The goal was to install Vincebar (which I have in my hands now) with epoxy and rivets to distribute load across a far greater and stronger area compared to just plates as over time the new cracks form on the RACP around the plates. The load of the subframe/engine/driveshaft twist is not modified via just plates so the next weakest point will fail. That's why I decided to trust Vince who is a mechanical engineer and based out of Sweden after he showed his solution to finally fix the E46 chassis rather than "prolong" damage.

    Vince's system is quite amazing and installing only requires just lowering the subframe but not completely removing it. Except as my subframe was lowered, the nightmare of many had become my reality. It was time to begin the lengthy process to fully drop the subframe.


    Subframe and Body RACP-5443

    You can see the front right RACP mount isn't looking too hot:

    Front RACP

    Just a bit devastating...

    Front Right RACP

    What I learned is that the subframe truly needs to be dropped to fully inspect as the size of the bushing can hide most if not ALL of the RACP failure in that area.

    Now for the front left, which shows failure beginning...

    Front Left RACP

    The rear right is showing the cleanest of corners but still signs of failure are happening...

    Rear Right RACP

    And now onto the left corner, the rear left...

    Rear Left RACP

    This doesn't look good. It's weird that even under inspections you couldn't see this.

    Rear Left RACP

    Thanks to Vince and the wonder of technology, he has studied my pictures and given me so much more information on this subject. He is also taking the time to fabricate some of the first Vinceskinz to epoxy/rivet into my car because it's in the air and there is an urgency to address and fix the situation ASAP. These "skinz" are like Reddish plates but they mold very tightly to the curvature of the RACP mounts from stage 1 to stage 4. The highest stage meaning more coverage due to more serious/lengthy cracking.

    During all of this, I asked Vince questions for more clarity.

    Why Epoxy and rivet your product instead of weld?

    "Epoxy will adhere the complete surfaces to each other, completely embedding the cracks. The rivets will not only clamp the skins to the RACP while the epoxy cures, but they will also tie the skins to the base plate, and other underlying multilayer parts of the RACP. The placement of the rivets is very thoroughly researched.

    Given the complex shape the skins are snuggly following, I really don't see that being possible without the rivets (think aerospace applications). The gaps would be too large which makes for a weak bond (which is most likely the issue for people who haven't really succeeded with epoxy installations). Even though I've made the Skinz fit very tightly.

    But if you're concerned about epoxying you could try welding them on. Just add a lot more small holes in which you could add plug welds. Otherwise, the Skinz will only be a thin plate slapped on top the RACP."

    Another question I ask was about spot welding and this was his response:

    "Yes, spot welding a little at a time is typically what needs to be done in order to weld that thin sheet metal with gaps.

    But it's not the warping you should be concerned about, it's the local heat in the spot weld weakening the metal. So the welded crack will not be as strong as before. And the crack is in that specific location because it's a high load area.


    That's why I argue you should cover the cracked area with a skin that is epoxied on. Which will effectively make that area, and a large area around it stronger.


    But yes, the VinceBar Kit does provide a significant load relief. So the cracked areas will not see stress anywhere near what they originally were subject to. So just welding could work. I just feel it's a bit of a gamble, and fabricating and fitting plates to fit snuggly is a lot more difficult and time consuming than you would think."

    When he brought up skinz for my car I asked him why use those over other "plates"?

    "Well, it's about covering the correct area and doing so while being smart about material usage.

    Slapping on thick plates will create stress concentrations at the perimeters of those thick plates (a large step in thickness), and that's also where they are welded, and the welding weakens the metal...


    Epoxied and riveted VinceSkinz are uniformly connected to the whole coverage surface making it a thickening process so to say, rather than a plate transferring load. Without weakening the metal by welding.


    Also, those plates leave much of the cracked area uncovered because it's difficult and time consuming to make plates cover those areas. So they simply drop that for cost reasons.


    Plates are not about transferring load, the load should be taken care of with the load relief solution. The plates/skins are about efficiently and smartly repair and reinforce weak areas of the RACP. To better take the local loads.


    The VinceSkinz are also very easy to install as they are already formed to follow the RACP. No hammering (that still doesn't provide coverage) is needed.


    And the VinceSkinz are so far the only commercially available "plates" that do not require welding."

    So I am getting schooled on how this all works and I'm excited that I will have a really buttoned down (or riveted down) mount for the subframe within the next two weeks. There are a lot of fine details to work out but I am getting great guidance from Vince and my buddy Josh who has agreed to be one of the first installers of this system. As I get more information I'll relay my findings to this thread since I believe this information will better arm all of you for the future.
    --Trevor--
    Vancouver, BC

  2. #2
    Yikes! Did you expect to see any cracks on the racp?


    Sent from my iPhone using Tapatalk


    2006 Coupe | Black Sapphire Metallic | Natural Brown | Gruppe M Intake | Corsa TSE3 | Michelin PSS on Apex ARC-8 | Koni Yellows |

  3. #3
    Join Date
    May 2011
    Location
    Charleston SC
    Posts
    6,149
    Anyone that has doubts about the strength of epoxy should catch a couple episodes of "How it's made: super cars"
    Most of chassis of the exotics are epoxied & riveted...
    Dinan CAI &Throttle body, ESS Tuning TS2, Bimmerbrakes gen3 headers, UUC SSK & DSSR. Achilles oil pump, VAC oil pan baffle
    M3 Motor mounts, UUC Trans mounts, Modified clutch style LSD 3.15, TMS front subframe reinforcement, Koni Yellow sports,
    H&R sport springs,
    UUC sway bars, BMW Perf. Rotors, UUC SS brake lines, Hawk HPS pads, CSL replica wheels,
    Rotora strut bar, FXR HID conversion, M3 Mirror conversion, BSW stage 1 speakers

  4. #4
    Join Date
    Feb 2011
    Location
    Vancouver, Canada
    Posts
    3,588
    Quote Originally Posted by san View Post
    Yikes! Did you expect to see any cracks on the racp?
    Never expected this much. I've had other E46 owners drive my car and there was no sign of sloppiness or irregular movement in the back. They noticed nothing. I asked Vince if he knew why nothing was felt and he just said that there simply wasn't enough RACP movement to change what I feel day to day. So I guess I can say my car is under moderate damage since I've seen some RACPs ripped much harder underneath and on the top layer inside the trunk. I'm just glad it's caught and that I resisted everyone's invitation to put my car on any track for any dragging or road racing...LOL. Who knows when I would have left the rear end on the ground at some point?? Hahaha
    --Trevor--
    Vancouver, BC

  5. #5
    Join Date
    Jun 2011
    Location
    VA/DC
    Posts
    14,445
    Wow. Those are big! Sorry for your woes but glad you found them (now) and that Vince has been so helpful.

  6. #6
    Join Date
    Jan 1970
    Location
    Lexington, KY
    Posts
    4,901
    "She can't take no more Captain"
    325i, 2005, 5MT, Silvergrey, leatherette, Sport package; CDV delete, KONI STR-T & KYB Excel-G, Weisslichts, Stewart H2O pump

    328i, 2010, 6MT, Spacegrey, dakota leather, M-sport packages; has a 330 intake but no tune - yet
    http://s900.photobucket.com/user/othibau/media/Junesig.jpg.html][IMG]http://i900.photobucket.com/albums/ac208/othibau/Junesig.jpg

  7. #7
    Join Date
    May 2011
    Location
    Charleston SC
    Posts
    6,149
    Quote Originally Posted by Oli77 View Post
    "She can't take no more Captain"
    Lol

    Dinan CAI &Throttle body, ESS Tuning TS2, Bimmerbrakes gen3 headers, UUC SSK & DSSR. Achilles oil pump, VAC oil pan baffle
    M3 Motor mounts, UUC Trans mounts, Modified clutch style LSD 3.15, TMS front subframe reinforcement, Koni Yellow sports,
    H&R sport springs,
    UUC sway bars, BMW Perf. Rotors, UUC SS brake lines, Hawk HPS pads, CSL replica wheels,
    Rotora strut bar, FXR HID conversion, M3 Mirror conversion, BSW stage 1 speakers

  8. #8
    Join Date
    Apr 2016
    Location
    Cape Town, South Africa
    Posts
    91
    Any updates, Trevor?
    2004 BMW 330i M-sport 6MT
    2003.5 BMW M3 Coupe 6MT


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