Need some input on rear suspension please

Discussion in 'Technical' started by Fordmaster169, Aug 24, 2010.

  1. Fordmaster169

    Fordmaster169 Member

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    OK, here is the question. How would mounting the coil over shock/springs on the front of the axle housing on a ladder bar suspension affect anything? After all, all they are doing is supporting the car and moving straight up and down. This would give me all the room I need to mount the Watts Link on the rear of the housing. Please let me know your thoughts (Good or Bad) on the application.
    Thanks
     
  2. Bryant

    Bryant forgot more than learned

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    its a mater of leverage. you may need slightly heavyer springs. it should work.
     
  3. MNTony

    MNTony aka Godzirra

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    I was always told that the shocks should be behind the axel in that application. But I can't for the life of me tell you who I heard that from (Alston chassis book maybe?) or why.
     
  4. Fordmaster169

    Fordmaster169 Member

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    Here is my thinking on the subject................
    If I move the Coil over in front of the axle, when I launch the car and the weight transfers putting load on the front of the axle housing forcing it in a downward motion. The rear housing is going to try to be rotating upward. Would that not take a little strain off of the ladder bars? I am going to write to a couple of chassis builders and see what they have to say about it and I will post the replies here.

    Thanks for the input.
     
  5. PaulS

    PaulS Member extrordiare

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    Having the springs between the axle and the pivot will increase the load on the ladder bars. Placing the springs on the axle will give you neutral load and the springs on the rear of the axle with the ladder bars forward will reduce the load on the bars.
    Remember that the weight rests on the springs and then is transferred to the wheels to the road. The longer the ladder bar gets away from the spring the less load it carries.
     
  6. MNTony

    MNTony aka Godzirra

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    Well the housing can't rotate with ladder bars anyway (essentially it is fixed) but it will rotate with regard to the front pivot point (instant center). I still thought that there was another reason for them to be behind the axle. But talk to an expert, they are way more qualified than I am! Let us know what you find out.
     
  7. Fordmaster169

    Fordmaster169 Member

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    OK, here is the result of my search, I contacted Baseline Suspension and S&W Race Cars. Both of them said the same thing. It will be fine to run the Coil overs in front of the axle tube. what they told me was that moving them forward only has one effect on the suspension. It changes the spring rate of the Coil overs by about 15-20% due to them supporting more weight due to the fact they are closer to the automatic center from the ladder bars. The application does not put any more stress on the ladder bars or the rest of the suspension. So the result is running a stiffer spring and setting the shock to a stiffer setting. So all is good for the mounting of the Coil overs in the front of the axle tube.
    Thanks for all the replies and thoughts.
    What this does do is gives us one more option on building our cars, and that is a good thing.
     
  8. markdulong

    markdulong New Member

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    definatly way to go mark
     
  9. markdulong

    markdulong New Member

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    reply

    this is a good application for your needs although regular shocks will work just fine and much less expensive
     
  10. MNTony

    MNTony aka Godzirra

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    Excellent information! I will stash that away in the back of my mind...now where did I put those car keys?!?
     
  11. PaulS

    PaulS Member extrordiare

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    Think about this for a moment:
    "It changes the spring rate of the Coil overs by about 15-20% due to them supporting more weight due to the fact they are closer to the automatic center from the ladder bars"
    If you have to increase the spring rate where is that weight landing? Since the axle is resting on the road and the ladder bars keep it from rotating they have to take some of that load. If the ladder bars were not there the axle would rotate forward with the spring load - the ladder bars take that extra load.
     

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