Anti-sway bar steel

[Icedawg]

What type of steel should you build a sway bar out of? I want to add a rod to the rear axle beam of a Festi axle, like the stock Aspire rear axle. The mount holes to weld to are in place on the axle. But what kind of steel, what grade, should be used for the rod?

[bhearts]

What type of steel should you build a sway bar out of? I want to add a rod to the rear axle beam of a Festi axle, like the stock Aspire rear axle. The mount holes to weld to are in place on the axle. But what kind of steel, what grade, should be used for the rod?

Some sort of stainless, so no rusting.

Sent from my SM-G900V using Tapatalk

[bhearts]

What type of steel should you build a sway bar out of? I want to add a rod to the rear axle beam of a Festi axle, like the stock Aspire rear axle. The mount holes to weld to are in place on the axle. But what kind of steel, what grade, should be used for the rod?

I would think some 304ss would be perfect

Sent from my SM-G900V using Tapatalk

[Advancedynamix]

304 has poor elasticity. Also, the weld joint between a 300 series and a mild steel will be prone to stress cracking. Your best bet would be simple hot rolled 1018 bar stock. It will provide a reliable weld, and is elastic enough to provide a torsional spring in that scenario.

[Advancedynamix]

Have you taken most of the static sag out of your rear shocks yet? It works better than a bar. Also bump stops work great to provide a rising spring rate where you need it. Keeping the pressure on the front inside wheel is the goal for both of us, but your surface (ice) is especially critical. I'm really interested in what setup works best for that. It would probably help a lot on the asphalt as well.

[bhazard]

304 has poor elasticity. Also, the weld joint between a 300 series and a mild steel will be prone to stress cracking. Your best bet would be simple hot rolled 1018 bar stock. It will provide a reliable weld, and is elastic enough to provide a torsional spring in that scenario.

No comment on how this will actually negatively impact handling?

I've heard of people using a piece of threaded rod through the holes in the beam. Would be the easiest way, no welding, easily removable. Just a nut on each side of the hole, on each side.

[blake4591]

Some people just used a piece of 5/8" all thread, washers and nuts to bolt the rod in through the holes.

Edit: Never mind Brad beat me to it.

[F3BZ]

i'm not commenting from any practical or metallurgical knowledge but all-thread? it might not be as implausible as using an empty pineapple can as a temporary piston but i can bend 1/2" all-thread over my knee. from what little i know i thought anti roll bars were usually made of something a little more exotic and heat treated n'at . i dunno. maybe the degrees of rotation are small enough not to exceed the point of deformation of "da thread"? i'd still be doubtful that nuts n washers thru a hole anchoring the ends would in any way approach the definition of solid. here's another 3rd world solution: how about just some like, 2" wide 1/4" plate steel beam clamped to the axle?

[bhazard]

I don't see the point to un-independent-ing your rear suspension anyway. Thats all you're doing is taking the twist out of the twist beam.

Nowadays we've figured out how to make a set of awesome coilovers for these cars so cheaply that why bother trying to rig the suspension to "work better"?

[sketchman]

Something I was told by an old hot-rodder when considering fabbing a new front bar.

How about a leaf spring? Vette style. Or would that even fit? IDK. But you could weld mounts onto the beam on either side, then you would not have to weld the spring steel at all. Just drill holes in the ends and bolt it/them on. You could even tune this way by adding or subtracting leaves, though I would imagine 1 would be plenty or even too much. Then you could tune by cutting some out of the leaf a little at a time.

[ryanprins13]

Anti-sway bar steel

another 3rd world solution: how about just some like, 2" wide 1/4" plate steel beam clamped to the axle?

Haha, i like that: 3rd world solutions

What type of steel should you build a sway bar out of? I want to add a rod to the rear axle beam of a Festi axle, like the stock Aspire rear axle. The mount holes to weld to are in place on the axle. But what kind of steel, what grade, should be used for the rod?

I have never done it to a car before but from what i have read adjusting your sway/lean with the rest of the suspension before adding or thickening a sway bar gives better results as advancedynamics said. However if you want a sway bar do you need to custom make one? The other guy-Robin- who was out ice racing his festiva has one. It looked to me like he took one off another car and modified it to fit the festiva. I didn't look too close though. Perhaps asking him what he did and what car he took that bar off of would be good.
However if your doing this more to keep your axle from snapping again rather than for anti sway properties just weld some narrow flat bar to it. Or hose clamp a few full length pieces all the way around so that when it breaks you can still drive did you get it off your trailer yet?


Sent from my iPhone using Tapatalk

[Advancedynamix]

Real sway bars are made from high silicon alloys that have been heat treated. That material should never be welded as it becomes brittle.
Most of the time there are ways around relying on a sway bar, but sometimes you've gotta use one. Ice racing may be one of those times.
Our LeMons car has a 22 gallon fuel cell, and I'm thinking about adding a bar in the rear to help control the roll from all that fuel weight. Normally, I don't recommend added beam rigidity, but the roll is discomforting for a few of our drivers, so I'd like to be able to contol it a bit with a full tank.

[Icedawg]

hmm a lot of ideas here. Thanks for so much feedback.
Advance I was not sure what you meant about the shock sag. I have cut, front Festi springs on the rear to stiffen a bit from stock rear rates, and lower the ride an inch or so, but I am not sure if that is related.
It sure looks like Kia just welded in the bar for the Aspire, so there must be some spring steel that can take welding.
First, I am simply trying to duplicate the Aspire rear beam, which does weld a rod into two holes in the Festi beam that are already there. It is well documented on this site that the Aspire rear beam is stiffer, but still bends, and makes the car handle better. Note I already have an Aspire front sway bar to accommodate lowering the cross member for the G25mr tranny, so the Aspire style rear is a better match.
Duplicating Kia's choice for how to stiffen the axle is a proven method.

Second, I have not located an Aspire axle, but have a Festi axle. Besides I want to keep the Festi bolt pattern given all my investment in race rims, and the fact I do not need much for braking when ice racing anyhow, so do not benefit from the heavier Aspire brakes. And the Aspire rear axle will not accept Festi hubs without drilling them out and weakening them. I did it once, but do not like it.

Third my current broken axle used a third world solution, and it is a fail. Three times the bolts holding the rod stiffener bolted to the welded on plates sheared. And then the plates, welded on to mount the bolts to, induced enough stress at the weld to be the weak point where the axle snapped in half. So, for racing that is a double fail.

Perhaps I could handle it with coilovers, I am not sure though. I want the soft springs I have, so coilovers seem a bit costly as a choice. When ice racing there is very little body lean, with no grip you slide instead of lean. So soft springs are needed to get lean and weight transfer. Soft shocks too, because the rough ice surface means a lot of pounding up and down. You also need a lot of travel to still be available. Hence a sway bar seems about right, which in the case of rear beam axle design means stiffening it with a rod for most manufacturers.

[Doug Brown]

One way of doing it is to get all your dimensions and send them to AADCO (think that's their name - they make swaybars).

I had one made for my friends Fiat-Abarth 1600 OTR. Cost $180.

I also had swaybars made for my Jaguar XK-E coupe (way back in the old days). A blacksmith formed them up for me and then had them heat treated to get the torsional properties back (heating to form the bar removes the initial torsional properties, heat treating brings it back))

If you need holes in the end of the swaybar for attaching it to the suspension, make SURE you have them drilled in the bar BEFORE it is heat treated as the steel is just about impossible to drill after the heat treating.

Or you can leave the ends un-drilled and use clamp on movable blocks to attach the link from the bar to the suspension. Go to a dirt track site where they make torsion bars (swaybars) for race cars. They will have everything you need - you just have to figure out what you need!

The dirt track torsion bars is probably the simplest way to go if you can find what you need. Everything is OTC - no moon rocket expense for a one off item. And you can get them in just a couple of days.

You can usually find used ones too, although you may have to look around abit. There are used dirt track parts stores that sell them.

Happy Googling!

[meyek91974]

Hey, if you can help me understand what you're wanting to do as I think I'm missing the plainly obvious.
You want a rear sway bar. OK- and instead of hitting a junk yard to snag one off an Aspire, Subaru, small Mazda, Vdub, or whatever, you're making one???
If I'm not missing out on something, wouldnt it work to get a Cabrio or small Toyota sway bar, make/mount it to the underbody, and get some sway bar end links to bolt to the rear end of the Festiva????
Also, are you matching roll weight strength or transferred inertia weight shift with front sway bar as otherwise you'd have a differing stiff rear and sloppy swaying front?

sorry if I misunderstand, but correct me if Im wrong; this sounds easier, simpler, cheaper than all that mocking up creativity