Torsional rigidity test: 67 coupe

Discussion in 'Classic Mustang Specific Tech' started by mustbereel, Oct 8, 2007.


  1. Helmantel

    Helmantel New Member

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    I think it's a good idea, but I would have designed it differently. Now it attaches quite a bit in front of the area were the chassis is loaded. Attaching it just in front of the upper A arm would help more. Also, The way it is designed now, there is a long horizontal section which can bend.

    A tube that attaches just in front of the A arm and goes up towards the fire wall in the straightest possible way (ina more triangulated way) would result in the stiffest construction, I think.

    A diagonal tube that attaches to the frame rail under/through the upper arm (where the shock bracket is currently located), with an attachment point for the shock would also result in a stiff construction.
  2. mrmustangman357

    mrmustangman357 Member

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    Wouldn't it be more benefitcial to tie it in to the front coilover? Like run a diagonal piece back from the tube to the torque box, then lay a horizontal piece between the two diagnonals for the front coilover. May be overkill, but there wont be ANY front end flex. Plus I feel sorry for whoever you accidently hit with their "crumple zones" HA
  3. twuxtop

    twuxtop New Member

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    reenmachine

    why did you put the bars on the wheel side rather than the engine side? did you do it to keep the engine bay stock and clean looking?
  4. reenmachine

    reenmachine Active Member

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    Yes, and your tire would hit it when you tried to turn. Everything is routed the way it is for a reason -- there are other factors to consider than just perfect textbook structure.
  5. reenmachine

    reenmachine Active Member

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    Same answer about not being able to turn your wheels very far.
  6. reenmachine

    reenmachine Active Member

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    Yes, for looks, and also because it would interfere with other stuff I'll have in the engine compartment.
  7. 70vert

    70vert New Member

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    Reen has the right idea, in my amateur opinion. (read a lot, no structural engineering or suspension or chassis background) At first I thought "hey, why did he send the bar so far forward? I have seen something like this on corner-carvers.com from the "Fire and Ice" Mustangs that are the next project for SN65. I like Reen's implementation: here's why:

    -Aforementioned issues of tire clearance
    -If you just tie it above the shock tower area, lots of sheet metal flex in there
    -attachment points for his style of suspension are right down there around the front frame rail.
    -related to above, if you have a stock style shock tower it kind of sucks because you would have to fab a reinforcement to the top of the shock tower that attaches to that metal tube, then send another down tube down to the frame rail behind the shock tower. Because, obviously, you couldn't go through the spring. Possibly around, and tied to the shock tower at the top with welds, and to the top of the inner fenderwell. Hmm.
    -I think it's better that it is done outside the engine compartment. Straighter load path to the roof/A pillar
    -It would be neat if it could be welded/attached to the flimsy sheet metal around the engine. I am a big proponent of marrying a cage type structure to the original unibody, but I am sure this would be a ton of extra work for this part. Nice bang for the buck, Reen!
  8. bnickel

    bnickel Founding Member

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    the best one i've seen of this type actually ran pretty close to way that Reens runs but after the shock tower (stock suspension car) it turned inwards and went through the fender apron and then down to the frame rail. it was also perimiter welded around the fender apron connection. you'd still have some interference with the starter soleniod and stuff mounted top the apron but that's stuff that's easily relocated so it's no big deal. it also had another brace close to the cowl connection that ran down to the framerail there as well, since the main part was attached very close to the outer end of the cowl the tube had a nice angle down to where it attached to the frame rail, so it added even more triangulation. this part is kind of hard to explain and i wish i had a pic of it to show you. it would be much easier to show you than describe it. i'm sure someone understands what i'm trying to say though.
  9. Helmantel

    Helmantel New Member

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    Even with the tube as close to the inner fender like you have it now? Well, I assume you put more thought into into it than I have.

    I need to remind myself that you're not really that guy with his inflateable penis :D
  10. reenmachine

    reenmachine Active Member

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    When I was mocking everything up I put a wheel on, and since the coilover's off I could move things through the entire range of motion. When the wheel's turned to lock and moved up and down it sweeps out quite a bit of real estate. I was also a bit conservative on top of that since I'm not yet sure what tire size and wheel backspacing I'll end up using or what the final ride height will be.

    I hate to admit I have no idea what the inflatable penis reference is all about. :shrug: Link?
  11. mrmustangman357

    mrmustangman357 Member

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    for your avatar. dodgeball?
  12. Helmantel

    Helmantel New Member

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    Exactly!
  13. reenmachine

    reenmachine Active Member

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    Oh crap! I can't believe I forgot about the inflatable penis! :bang:
  14. mrmustangman357

    mrmustangman357 Member

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    so reen do you have a piece of pizza in your pants right now too?
  15. reenmachine

    reenmachine Active Member

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    I'm not sayin'....but I really covet a giant painting of myself grabbing the bull by the horns!
  16. SoCalCruising

    SoCalCruising Founding Member

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    mustbereel:
    Geez, I've been traveling and just saw this post. Terrific.
    What does everyone think that the TCP shock tower brace is worth in rigidity? It not only ties the shock tower to the cowl, but to the cross brace ("Monte Carlo bar"), too?
  17. Jester67

    Jester67 New Member

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    Someone mentioned seam welding earlier what is everyone’s thoughts on doing that. I must admit I have argued both sides of it and am still not convinced what is the better way to go.

    Seam welding would be stronger than spot welds. But do you really need that strength and is the surrounding metal able to take advantage of that strength.

    It would remove the need to use seam sealer but would be a lot of work and seam sealer lasts a very long time.

    I could foresee it taking ten to 20 pounds of wire to do the whole car would that just be added weight and cost.

    So what do you think?


    PS: I think this is a great thread. I do wish you would have posted your plans before you started I think you would have gotten advice on a better starting point.
  18. bnickel

    bnickel Founding Member

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    i don't that i'd do the entire car but some key areas for sure, suspension pickup points high stress areas like torque boxes and rear apron to firewall probably, maybe the rear wheelhouses to the trunk floor and also the rear rails to trunk floor possibly.
  19. mustbereel

    mustbereel Member

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    Thanks SoCalCrusing. I'll be back with stage two in December when I test the frame reinforcement braces I made, new diagonals to the cowl, a sheet metal divider behind the rear seat and jacking rails to connect the subframe connectors to the outer rocker panels. Stay tuned!

    As far as the TCP setup is concerned, triangles are a good thing but it looks like the primary advanage is the clearance offered by positioning the cross brace further forward. I wouldn't expect to see much additional torsional resistance due to the extra two links.
  20. mustbereel

    mustbereel Member

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    Jacking rails

    In preparation for the next round of testing I have finished the jacking rail/sfc assembly. The SFCs are from Heidts and the jacking rail kit came from Global West. I purchased it from Summit Racing for about $130. Since it was made for Global West SFCs there was quite a bit of modding and fabrication required. The 1 inch square tubing welds to the rocker panels. The portion that extends forward will tie into the front torque box. The kit appears to be designed for installation on a car without front torque boxes so more mods were necessary.

    [​IMG]

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