No announcement yet.

Torsion to air suspension

  • Filter
  • Time
  • Show
Clear All
new posts

  • Torsion to air suspension

    Hello everyone, I am looking for some help with my current situation. The situation: 1966 Plymouth Valiant Wagon. The front has torsion bar suspension and the rear has leaf springs. I know a 4-link setup would be best for the rear, I am just confused on how and what to do with the torsion bar setup. I know people have been doing this with the mini trucks as they have the torsion bar setup as well, I just can't seem to find any build pics or anyone who knows what to do. On my valiant forums people are telling me it would be way too much work and wouldn't be worth it. I just love the slammed look, but would also like to go over speed bumps and not bottom out on everything! Would love to hear some of the techs ideas for the setup I should go with... Thanks-Zach

    Click image for larger version

Name:	val.jpg
Views:	1
Size:	91.4 KB
ID:	44854

  • #2
    It is possible to put air on a torsion bar car. . .in fact it's not really all that difficult.

    We offer kits for the 68-74 B and E body chassis which utilize torsion bars. We supply a tubular upper control arm and a 7000 Series Shockwave. The tubular arm is required to clear the Shockwave. While the 7000 Series Shockwave would not be capable of lifting the front of those cars on its own, it is possible if we leave the torsion bar in place, albeit at its softest setting.

    Here's a link to our B and E body page:

    Here's a link to the instructions which provide some images on how we make this work.


    • #3
      Huh... keep the torsion bars? The shockwave can't lift the front end up? It has a slant six, like 500 lbs. isn't the shockwave rated for 1,500-2,000 lbs per axle? I mean you would know better than me, I'm just thinking out loud, my car can't weigh more than 6,000 lbs... And if I do keep the torsion bars, would I be able to "slam it"? Thannks


      • #4
        Let's say your car weighs 3000lbs and has a weight balance of 50/50 (which it doesn't. . .it weighs more and has a F/R% much worse, so this example is possibly the lightest case scenario).
        Anyway, in our example the front axle is holding up 1500lbs total, or 750lbs per side.
        the Shockwave mounts in the OE shock location, which is roughly in the center of the OE lower control arm. Therefore, the front has a motion ratio of 2:1 (the shock/Shockwave moves 1 inch when the wheel/tire moves 2 inches. Also, the shock/Shockwave carries twice the load as the wheel/tire). So the shock/Shockwave has to be able to lift 1500lbs total in our example.
        The 7000 Series Shockwave is capable of lifting 780lbs at 100psi (
        If you place the Shockwave in there by itself it won't lift the front of the car.
        Now, say the torsion bar provides a spring rate of 500lbs/in, and you compress it 2 inches (minimum distance of typical vehicle compression).
        With the torsion bar and the Shockwave combined they will lift 1780lbs, which is enough to lift the front end.

        Will you be able to "slam it"? That depends on what you mean by "slam it". With this setup you'd be able to lower the vehicle as low as it would go if you disconnected the torsion bar all together. How low is that? I don't have the foggiest as I've never dropped a 66 Valiant. However, my guess is that it would look extremely low. . .low enough you couldn't drive it, but not so low that it drug anything on the ground, so it would still roll.

        The skill level required to accomplish this is a bit on the higher end. . .you'd have to be able to source a tubular upper arm with the proper geometry (or build one), and possibly build a set of spacers to fit the Shockwave to the OE lower control arm.
        It's not exactly building a custom one-off frame. . .but it's not sticking on some cool flame and tribal graphics from the local auto parts store either.


        • #5
          Okay that makes sense, and thank you for taking the time to explain it in depth... my last question would be, what setup are the mini truck guys using? Most of those trucks have the same torsion front end and can "slam" their trucks and then raise them back up 4-6 inches and drive over speed bums and such... Thanks


          • #6
            Honestly I couldn't tell you what the mini truck guys do. That's not really our "cup of tea", and I've never really looked under one (and I've been intimately involved in every vehicle kit we've developed in the last decade).

            You would be able to slam the car. . .at least what I call slammed. That is the lowest it will go while still being able to roll. When we design a kit that is all the lower we'll go as it's a safety issue.
            If you were driving down the Interstate at 70mph with a bunch of other vehicles and you experience a catastrophic failure (say a large rock is kicked up by the tire and damages the main line to the tank. . .unlikely, but possible. . . and the tank looses all air. . .the vehicle will deflate to the bumpstops).
            If you have the vehicle setup where it still rolls you can safely get to the side of the road.
            If you lay frame and traffic is heavy you'll be stuck on the road. . .with a bunch of other cars going 70+mph. God forbid a bus full of nuns, or a texting soccer mom in a kid laden minivan, kits you and kills someone. . .now you are liable and wearing orange.


            • #7
              Lmao, okay sounds like I have what I needed to know. Thanks for sharing your knowledge with some humor...