Would anyone be interested in traction bars?

[Sho_tyme_psi]

Just wondering if this winter if I throw togather a few kits if anyone would be interested in these. They would require some welding to the frame rails but I feel these would make a world of difference since we have floating control arms. Just wondering If anyone would find these of interest.

[Jimmy]

I've been thinking about building a set just for the purpose of divorcing anti-roll from longitudinal location. I think it's definitely a worthwhile project, but I probably would just make my own rather than buy a kit.

FWIW I built a set for my Sentra and they helped tighten up the steering as much or more than they helped with wheelhop.

[B6T]

I've been thinking about building a set just for the purpose of divorcing anti-roll from longitudinal location.

What's that mean, for those of us who having read that part of the internet yet...

[Jimmy]

I've been thinking about building a set just for the purpose of divorcing anti-roll from longitudinal location.

What's that mean, for those of us who having read that part of the internet yet...

On a stock Festiva, the sway-bar also keeps the front wheels located front-to-back in the wheel-wells. It's nice from a simplicity point of view, but for performance it has it's drawbacks - a big one being that it limits your aftermarket sway bar options and pretty much rules out adjustable front sway bars. It also means that all of those bushing are doing a lot of work, seeing a lot of different loads.

If you made radius arms (AKA FWD traction bars), you could remove the sway bar altogether if you chose to. You could also make a setup that would allow you to mount your swaybar to the traction bars near the control arm. That could open up a lot of front suspension tuning option.

Kinda hard to explain, I'll sketch something up in Solied Edge later tonight and post it. Might make more sense that way.

[Jimmy]

Quick and dirty sketch here, but this is along the lines of what I had in mind.



The yellow is part is the stock control arm.

The black could be a stock sway bar, or if the builder were slick could be a sway bar with the right dimensions taken from an application with more aftermarket support. The design of the ends is not important because the bar's end points won't be used.

The green part is a short link that would be better if it were spherical rod ends, but that might make it too long put too much angle on the bar.

The sway-bar center links would have to be redesigned, probably cut from billet aluminum with just thin poly sleeves instead of bushings.

Ideally bolted below the center links would be clevises to hold the end of the radius arm (the rod end floating in space in the pic).

Sway bar stiffness could be adjusted by loosening and sliding the green links closer to the front or back.

Additionally by moving the pivot of the radius arm down (a by-product of moving it to below those new sway bar center blocks) some amount of anti-dive will be dialed into the front suspension. The thickness of those blocks could be tailored for the application.

Anyway, it's a start.


UGH! Pic won't work. It's in my gallery Link Here.

[htchbck]

looks like fun... I got no money, so obviously I'm not expressing interest in buying one, but you seem to be on the right track. I've thought a couple of times about trying to find a car I could jack indie front suspension from, but I'm always too lazy to do it, plus I don't have a welder right now...

[Hot_Wheels]

jimmy when you going to indiana?? help me with my suspension and ill give you that motor

[Kraig]

Shouldn't you move the front pivot point of the radius arm in line with the control arm inner pivot to simulate a lower A-arm? Keeping it in the position drawn will have the wheel moving forward as the suspension compresses and probably create bump steer.

[Jimmy]

Shouldn't you move the front pivot point of the radius arm in line with the control arm inner pivot to simulate a lower A-arm? Keeping it in the position drawn will have the wheel moving forward as the suspension compresses and probably create bump steer.

Yeah, I meant to mention that. I learned that the hard way when I built the first set for my Sentra. Not so much bump-steer, but the suspension would bind really bad in bump.

I was in a hurry when I drew that model so I didn't have time to get the angles right. The front of the radius arm/traction bar would be a clevis bolted to the bottom of the sway bar blocks.

When the weather cooperates again, I'd like to get all of the measurements of mounting points, etc off of the Festiva and get the suspension really setup. I think with all that stuff done, plus maybe some basic roll-center adjusters in the front and a Panhard for adjusting the roll-center out back, the Festiva could be a graceful handler.

[Kraig]

Cool

[shorestiva]

If I had money I'd be interested.

[IdealSociety]

keep us posted as ive been a hater of the front suspension on our festivas since my first control arm replacement... that and after being a fiero enthusiast festivas just could really use a bolster in handling performance that needs to go well beyond a simple spring/strut replacement...

[B6T]

Quick and dirty sketch here, but this is along the lines of what I had in mind.



The yellow is part is the stock control arm.

The black could be a stock sway bar, or if the builder were slick could be a sway bar with the right dimensions taken from an application with more aftermarket support. The design of the ends is not important because the bar's end points won't be used.

The green part is a short link that would be better if it were spherical rod ends, but that might make it too long put too much angle on the bar.

The sway-bar center links would have to be redesigned, probably cut from billet aluminum with just thin poly sleeves instead of bushings.

Ideally bolted below the center links would be clevises to hold the end of the radius arm (the rod end floating in space in the pic).

Sway bar stiffness could be adjusted by loosening and sliding the green links closer to the front or back.

Additionally by moving the pivot of the radius arm down (a by-product of moving it to below those new sway bar center blocks) some amount of anti-dive will be dialed into the front suspension. The thickness of those blocks could be tailored for the application.

Anyway, it's a start.


UGH! Pic won't work. It's in my gallery Link Here.

Ah. I know what you're talking about now. I thought of doing something like that while I was working at the shop, and I mentioned it in this forum somewhere, but decided against because it's a lot harder and very expensive to have those little parts made in real life then it is to make them in Solid Edge. I just don't have the time and money to deal with that right now. The stock suspension was working fine enough for me anyway, I don't really push it hard through corners that often. It's a good idea though and I'm sure it would work out well if someone actually did it.

You should really take some measurements before you put too much time into your ideas, I think you'll find that there isn't much extra space up there. You'll have a hard time fitting a sway bar above the A-arm for sure. If it were me designing it, I would have removed the sway bar and its brackets and used those mounting points to bolt a custom mounting plate to which I would attach the custom made tension rod (which is what it looks like you've added). To attach the tension rod to the control arm, I would use a ball and socket joint (or whatever you want to call it, I don't know the actual name) similar to those used for inner tie rods (a lengthened inner tie rod might actually work, but proper load calculations would have to be done first). I would then see if a sway bar could be mounted on the firewall, either above the steering rack and connected to the control arms with levers and push-rods, or below the front subframe and behind the wheels (limited ground clearance would be a factor here).

Those are my ideas, I hope they help.

Another thing I was planning on doing but never did was to modify the steering rack and move the inner tie rods out farther to reduce or even eliminate bump steer.

[Sho_tyme_psi]

My idea was actually backwards. I looked at it that way and decided no go. I am planning on welding sub-frame in the full length of our subframes and welding a bracket to it, then hooking it to the back side the controll arm with a bracket on the swaybar/nut. Ill keep posted on how mine turns out also.

[nattyphysicist]

Anyone make any progress on this? I hope to tackle this problem one day. I really don't like the lack of triangulation in the control arm.