Register now to get rid of these ads!

Suspension- Will this Work?

Discussion in 'The Hokey Ass Message Board' started by Splinter, Jul 15, 2007.

  1. Splinter
    Joined: May 14, 2005
    Posts: 1,112

    Splinter
    Member

    Allright, when I started this build, I was just going to use the rear bones to hold in my rear end, but after reading a number of threads on here about the "Less Than Safe" nature of this, I decided to make it a 4-link. Running a BUILT 401 punched out to 413, balanced & blueprinted, Radical cam, etc., figured beefy, splayed out rear links would keep the rear end from getting all twisty. I scored the stuff to make my links, and did so. I'm mocking it up, and just wanted to see if ther was anything I am missing. The links have about 2 deg. up angle to the crossmember.

    Will it work, or am I building a rigid rear end for "El Juapo"?

    Thank You!
     

    Attached Files:

  2. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109

    scottybaccus
    Member

    A 4-link is hard to do with a transverse leaf, Especially with such short upper links. You will see a noticeable change in pinion angle with such short links. That might be tolerable since you have so little suspension travel, but binding is almost certain with the transverse leaf. I can't see what you are doing for lower links, but it looks like you still have the bones on there. If so, you can't use the stock axle attachment. It will not allow the housing to pivot like a true 4-link. Do you have any pictures showing the lower components?
    The upper links should also slope down a few degrees to the crossmember. Read up on how instant center is affected by link angles and you will understand why.
     
  3. Splinter
    Joined: May 14, 2005
    Posts: 1,112

    Splinter
    Member

    The lowers are just '36 split radius rods, attached to the outside of the frame about 9" forward from the back of the cab (on the right in the photos). They are attached to the axle with 2-bolt brackets. The main reason I spread the links out was because I knew that I could not match the arc of the lowers without matching their lenght, etc. I was kind of emulating the later Mustang suspensions with the much shorter upper links, thinking that if I spread them out, I would get them out of similar arcs and allow the heim joints to do the rest...does that make any sense?
     
  4. Can your lower links roate relative to the rearend? because with the short upper links you will have pinion angle changes. Unless you can move at the lower link the upper bars will be in conflict with the solid lowers.

    The other issue is the instant center. You said the upper bars go UP to the cross member? That would put your instant center way out front of the car if they even come to an intersection point. Have you considered this?
     

  5. Splinter
    Joined: May 14, 2005
    Posts: 1,112

    Splinter
    Member

    Phooey. The more I read here, the more I realize that this might not work so well. Might be time for some re-engineering. Good thing I haven't welded the links or tabs on yet!
     
  6. Splinter
    Joined: May 14, 2005
    Posts: 1,112

    Splinter
    Member

    OK, checked the rear raduis rods, and found out that they have 7 deg down incidence, so without another pivot point, I've just turned my rear end into a Heim joint compression/tesion failure device. Anyone have any ideas on how to get this thing strong nough to work?
     
  7. Nocturnal
    Joined: Sep 18, 2005
    Posts: 254

    Nocturnal
    Member
    from CO

    I have seen a good post in the Tech section under "chassis" or "Suspension" that has many pics and may help. In a nut shell, this will work IF you can make the bones flexible at the rearend....like with another heim joint/bracket.
    I didnt want to do this either, SOOOO I copied the "Rolling Bones" sedan and they actually turned the radius rods into a ladder bar by welding a bar to the front of the radius rod, utilizing the same pivot point and attaching the other end to the top of the axle by the differential......add a couple of gussets and you have a visible radius rod with the strength of a ladder bar.
     
  8. Nocturnal
    Joined: Sep 18, 2005
    Posts: 254

    Nocturnal
    Member
    from CO

  9. Splinter
    Joined: May 14, 2005
    Posts: 1,112

    Splinter
    Member

    I remember another car on here that used something similar to what I'm trying to do here....Was it metalshapes? Used stock rear bones and added upper links for strength.
    Anyone?
     
  10. 2manybillz
    Joined: May 30, 2005
    Posts: 835

    2manybillz
    Member

    The big thing is you hafta have a heim or some sort of pivot at both ends of the lower links/bones, then it would work. To get it to work "properly" will require getting the instant center right.
     
  11. john56h
    Joined: Jan 28, 2007
    Posts: 1,760

    john56h
    Member

  12. I'm sorry to help confirm that you are on the wrong track trying to use the bones along with the short upper links. You are going to end up with very drastic pinion angle changes with the big difference in length. Even if you take the rear leaf out of the equation (which will absolutely bind) you are going to have problems.

    The upward sloping links are also a big no-no.

    By the look of your truck i think you would best support a parallel 4 bar. They sell a kit for like 200 bucks on speedway or you can get the end links and make the brackets and links to save some scratch. They are only like 22" long and will probably stop about even with the back of your cab. They will also work well with your tranverse leaf setup.

    You could also go with a radius rod/ladder bar setup if your worried about strength. I run this in my T and it works well but it can be hell on your ass on a bumpy road. They are also typically pretty long and will mount somewhere under the cab (which may or not be a problem for you).

    Good luck...
     
  13. Slag Kustom
    Joined: May 10, 2004
    Posts: 4,312

    Slag Kustom
    Member

  14. Nimrod
    Joined: Dec 13, 2003
    Posts: 856

    Nimrod
    Member

    I think metalshapes as well as my roadster are set up sort of like what you are doing. I'm using 36 bones for the lowers. Uppers are triangulated outward like yours but probobly three times as long which would lessen the amount of pinion angle change as the suspension moves. And the lower bars HAVE to be able to pivot at both ends, I used urethane bushings at the rear axle so that my curved '36 bones wouldn't roll on their axis (don't know if I said that understandably).
     
  15. DICK SPADARO
    Joined: Jun 6, 2005
    Posts: 1,887

    DICK SPADARO
    Member Emeritus

    Saw your chassis post and have to caution you on that idea. Nice welding practice. This set up, as others have remarked wont work easily. What you initially have is more than sufficient. The 36/6 style radius rods are adequate for this set up, combined with the transverse spring set up, providing you are not into serious tires and intend to drag race this vehicle. What you should be looking for is a placement point for the shock absorbers.

    One more question/ observation would be in regard to the ride height in the picture. From what is shown, if this is ride height, this thing will bottom out on the first piece of gravel that you run over. There should be a minimum of 3 inches of travel between the top of the axle and the chassis.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.