anyone interested in a new watts link and a 3 or 4 link in here

Discussion in 'Classic Mustang Specific Tech' started by bnickel, Oct 23, 2005.

  1. Attached Files:

  2. light duty or mustang housing

    Attached Files:

  3. Thanks for the links. I have seen similar ones. It seems like the pumpkin dimension is a mystery. Although the first link you listed has the torino 9" housing at 9 3/8". I guess I will measure my housing to see what I get.

    As for the axle tubes, we can accomodate both 2 3/4" and 3" tubes.

  4. EvM Three Link Images

    Hey Everyone,

    We wanted to provide an update on the Vintage Three Link Suspension for the Mustangs.

    We are basically done with the design and are just preparing the drawings for our production prototype. We should have everything out in the next few weeks for the production prototype.

    We have included some images on our site so you can get an idea of what everything looks like.

    The EvM complete Three Link rear suspension for the vintage Mustangs (1965-1973) will incorporate a Frame Mounted Watts Link, lower control arms, an upper link, rear adjustable stabilizer bar and a bell crank driven coil-over system. The systems will be 99% bolt-in and will not require any modifications to the vehicle structure, beyond a few drilled holes. All systems will have an aluminum link upgrade option and will be available in various “kit” forms.

    Let us know if you have any questions.

  5. how much $$$ are we talking here...for a complete setup?
  6. We are still waiting for quotes. With that said, our target price for everything is $3500.00. That would include the Watts, Three Link with billet aluminum links, the rear adjustable stabilizer bar and coil-overs.

    This pricing may be a bit aggressive with the aluminum links, but the $3500.00 target is our goal.

  7. Mike, can you explain the pushrod coilover too me? is it similar to the TCP setup? it looks as if they pointing directly rearward so i'm guessing a rear exhaust is out of the question in this case, correct?
  8. The coil-overs are pointing rearward. I don't think rear exhaust is totally out of the question. It will just be a little tricky. We are working on some pre-bent tubes to run the exhaust.

  9. how will they mount? are you going to make some sort of framework to mount them to or will they just mount on the frame rail somewhere?
  10. We will have brackets that mount to the frame rail. The images we posted do not have all the bracketry in them. We figured that would just add to the confusion.

  11. that's what i thought, was just checking.
  12. With the coilovers pointed aft, are they going to provide any roll control? Is that why you have the stabilizer bar?
  13. Yes, the coil-overs oriented fore/aft provide roll control. The cradle, bellcrank and shock are all fixed to the body. The coil-overs attach to the axle with a push/pull link, and as the vehicle rolls, on one side the bellcrank is pushed up by the link and the shock compresses, and the opposite occurs on the other side.

    The stabilizer bar is there for suspension tuning. It will will give you the option to avoid using super stiff spring rates in order to balance your car and make fine adjustments.

    The stabilizer bar is not a requirement of the three link.

  14. For us stupid people

    can you tell me the advantages of your three-link system over the RRS 3-link or Heidt's 4-link or IRS. I was looking at your site and it's quite impressive, but I have no comparision to what it provides vs others.
  15. I guess the best thing to do is compare the generic systems first. So, the RRS is essentially a Watts and Torque Arm, the Heidts system is a 4 link with Panhard Bar and the IRS is, the IRS. With that said, here are some general talking points.

    Watts Link/Panhard Bar:

    WL: Constant Roll Center Height While Cornering
    PHB: Roll Center Rises in One Direction and Falls in the Opposite Direction

    WL: True Vertical Motion of Axle Thru Jounce/Rebound
    PHB: Axle Travels in an Arc defined by the Length of the Panhard Bar

    WL: Lateral Loads Reacted @ Both Frame Rails
    PHB: Lateral Load Reacted @ One Frame Rail

    Note: The constant rear roll center height, of a Watts Link System, will give the vehicle consistent and equal handling on both left and right turns. The overall benefits to the performance enthusiast include improved steering response, linearity, turn-in and overall cornering response, making the vehicle more predictable and easier to drive on all road at track surfaces.

    A Watts Linkage is a lateral control device which consists of (2) horizontal links, (1) vertical link and a structural cradle. The cradle is mounted to the vehicles rear sub-frame (sprung weight) and used as a mounting location for the Watts Linkage. The vertical link or “Crank” is mounted to the center of the cradle which is designed to be at the centerline of the vehicle cross-car. The horizontal links are both mounted to the crank; one at the top and the other at the bottom. The opposite end of each link is mounted to a tower that extends from the rear axle housing. When the vehicle is at ride height, the optimum (rear view) orientation for the links is parallel to ground, with the crank positioned vertically. The optimum (plan view) orientation for the links is parallel to the rear axle tube.

    The Watts Link System positively locates the rear axle, preventing it from moving side to side while cornering. With the rear axle essentially fixed in the lateral direction, there is now more real estate for larger rear tires without the worry of tire interference with the inner wheel well while cornering. The rear roll center is also lowered to be approximately equal in height to the center of the crank pivot. The rear roll center is the point where the lateral force is being transferred from the sprung weight to the unsprung weight. Lowering the rear roll center will reduce the portion of lateral weight transfer due to roll center height (a parameter which is not easy to tune) and allow the customer more freedom to tune front and rear roll couple distribution. The geometry of a Watts Link System also produces a constant rear roll center height while cornering unlike a panhard bar which has varying roll center height depending on whether you turn right or left. The constant rear roll center height, of a Watts Link System, will give the vehicle consistent and equal handling on both left and right turns. The overall benefits to the performance enthusiast include improved steering response, linearity, turn-in and overall cornering response, making the vehicle more predictable and easier to drive on all road at track surfaces.

    More Notes:
    While a vehicle is cornering and producing lateral force, the axles natural tendency is to move in the cross-car/lateral direction. With a Watts Link installed, as the vehicle builds lateral force, the lateral force is transmitted through the links into the crank, then into both frame rails through the cradle. Since one link is in tension and the other link is in compression, the load in each link is equal and the crank will not rotate. Since there are two links and one crank the lateral load is distributed between each of the two links and both frame rails, unlike a panhard bar which relies on one link and one frame rail to react all the lateral force. When the vehicle is not cornering, as the suspension goes into jounce and rebound, the crank travels with the body and will rotate to compensate for the vertical rotation of each link. This geometry will produce true vertical motion without any lateral component, unlike a panhard bar that will travel on an arc defined by the length of the panhard bar link.

    Ok. Next, the Three link.


    • Less Un-Sprung Weight
    • Improved Ground Clearance. Generally Torque Arms have reduced ground clearance below the Differential.
    • Dynamic Instant Center (IC) and Side-View-Swing-Arm(SVSA) Geometry is created by the Upper and Lower Control Arms unlike a fixed SVSA Geomerty of a Torque Arm. The Trilink geometry allows the vehicle to have increased Anti-Squat during acceleration for maximum bite while accelerating and increased Anti-Dive while braking.

    Benefit of Three Link over Four Link

    • Generally Less Components, therefore, Less Weight
    • Less Tendency to Bind While Cornering
    • Generally More Linear Through Full Range of Suspension Articulation

    The IRS has its own set of issues as well. In General,

    • The IRS is prone to power hop and brake hop.
    • The IRS is very sensitive to ride height, relative to half shaft angles.
    • Generally, you have issues with torque management as related to the IRS Cradle and Differential Durabilty.

    None of the systems you mentioned have a Stabilizer bar, the benefits of a stabilizer bar are….

    • Allows you to separate Ride Tuning from Handling Tuning
    • Gives you the ability to fine tune the overall vehicle handling balance/response

    So, that summarizes some of the differences between the systems. Beyond the kinematics of the systems, considerations need to be made w.r.t material selection, adjustability of the system and the general aesthetics of the system. We are not intimately familiar with any of the specific systems you mentioned, but they may be compromised when adjustability and real world inputs are applied to them. We are from an OEM background, so all of our systems are designed with real world suspension parameters (i.e suspension travel).

    Hope this helps.

  16. Awesome

    Thanks for the education.
  17. No Problem....:)

  18. I find that to be a very good general overview for a question that gets asked a lot.:nice:
  19. Will the ride height be adjustable like normally mounted coilovers, and if so, by how much? Also, are the shocks adjustable, and if so, single or double adjustable?
  20. Yes, the ride height will be adjustable. The suspension is designed at 1 1/2" lower than stock. At this position you will have 3" of jounce and 3" of rebound. There will be further adjustments via link adjustment and jounce travel restrictions.

    The system will also have rebound stops to maintain coil spring to spring seat interface under hard braking and/or full rebound.

    All the details are still being finalized. We will update as appropriate.

    Both single and double adjustable shocks will be available.