Currie Anti-Rock users, couple questions

[Roxtar]

This is primarily for Farmer Matt and anyone using them for the rear.
I'm trying to design an anti-sway bar to run across the top shock mounting bar with long legs running through the floor down to the axle:

My goal is to put a little more force on the shocks in an off camber situation without hindering flex too much.
Questions:
-How long are you running your arms(they're adjustable, right?)?
-Do you know what size/material the main torsion bar is?
-General notes on plus/minuses.

I'm trying to keep trial & error to a minimum, here.

 

[FarmerMatt]

I bought my "kit" through Rock Equipment. I'll measure out the length of the arms for you. My arms only have one hole punched in them at the very end. There is room to punch more holes closer in if you feel like you need more sway control. I'm pleased as punch with how stable the CAT feels in harry situations & that was what I was going after. I'm still using all the travel that my 14" shocks can provide.

 

[Roxtar]

Great, please measure the main rod diameter, also.
Any ideas what material it is?

 

[Captain Ron]

My goal is to put a little more force on the shocks in an off camber situation without hindering flex too much.

I'm using the Currie Universal set-up, 35" long, with the 18" arms. Check here:

http://www.currieenterprises.com/cestore/antirock.aspx

All of the engineering data is listed. I'd say you want to design for as
"square" of an installation as possible, but it seems to me that they tolerate quite a bit of off angle in both planes of the links without too much compromise in performance. Mine is a less than ideal install... I missed my initial width for the torsion bar I got, and ran out of room for the arm length I have, and it's still a workable situation.

Questions:
-How long are you running your arms(they're adjustable, right?)?
-Do you know what size/material the main torsion bar is?
-General notes on plus/minuses.

I'm trying to keep trial & error to a minimum, here.

-The arms are a set length with adjustment holes, the links are cut and weld to length. I tried to get as close to my shock extension length as possible, but ended up short. I wanted 16", got 13". Currie supplies a 11/16" x .120 x 18"" piece of CM tube you cut to fit. I still have full shock travel at my current adjustment hole settings.

-It varies on the Currie with the length. Everything is listed on their site.

-In my case, I consider it a necessity to run it. It was fairly easy to dial in for me, changes were manifest in immediately noticable effects. One thing to not discount is the center limit strap length... I would not have thought it would be a contributing factor, but it is. I shortened up an inch, front and rear, and it made a significant difference.

Carefully consider the complications of an "over the frame rails" installation verses the typical tube frame "under the rails" install. I'd imagine that ideally, in your case, if you could match the torsion bar length at a given hieght along your vertical shock path, mount there, and have your links follow your shocks at a bit closer to vertical, you'd probably be golden.

I can get pretty tippy and still be planted. It takes a bit of getting used to, the final unload happens fast and is more a function of tire sidewall at this point.

--ron

 

[FarmerMatt]

My arms are 16" from center of shaft to center of joint. The shaft itself is 1" OD at the end (splines), but I know it's turned down somewhat inside. I have no idea what the material is.

Matt

 

[Roxtar]

I found the material and diameter from Currie's web site.
They use 3/4" 4130 through hardened.
In talking to a company that does hardening for me, he recomended 4140 over 4130 due to the ability to oil quench rather than water quench which causes a lot of distorsion.

Anyone know of steel companies that might deal with aerospace spec stuff?
I'm looking for 4140 bar in an AMS 6418 spec.

 

[Captain Ron]

http://www.twmetals.com/

--ron

 

[Mike L]

Updates?

 

[BrettM]

If you're trying to build it cheaper, some of the circle track catalogs have them cheaper than offroad applications, and then you get a known spring-rate.

I question the practicality of mounting it so far above the axle.... are you sure? I've also seen some mount the torsion bar to the axle and run the links to the body.

 

[Roxtar]

It's being heat treated now.
Taking it to 50-55RC.
Hoping to have it all together this weekend.

Looked at all mounting options, what few there actually are, that is.
Upper shock mount was far and away the best.
No reason I can think of that long (42") links should cause a problem.

 

[BrettM]

not that the length will hurt, it just seems like there should be an easier way... seems like that setup will further kill any cargo room.

and it would seem the longer links would be more prone to buckle under compression, though I will assume you used a sufficient material

 

[Roxtar]

not that the length will hurt, it just seems like there should be an easier way... seems like that setup will further kill any cargo room.

Cargo room?
Oh yea, I remember that.
Didn't XJs come with some of that?

Actually, I'm keeping them as wide as possible. The links run down next to the wheel well.
Still using up space but really not too bad.

though I will assume you used a sufficient material

Not a whole lot of worries there.

 

[Weasel]

won't having the links that long create some pretty big moments on the torsion bar?

 

[Roxtar]

won't having the links that long create some pretty big moments on the torsion bar?

The arms off the shaft are only 15" long. The length of the links between the arm and the axle won't have any real effect.

 

[Lincoln]

The arms off the shaft are only 15" long. The length of the links between the arm and the axle won't have any real effect.

I think (or at least I hope) he was talking about the twist in the bar. Only the longer arms will cause it to be softer from less twist. Hell, I even confuse myself.

How far can one of those be twisted before causing it to weaken anyway? For some reason I have 20 degree but I have no idea where I came up with that.

 

[Roxtar]

I think (or at least I hope) he was talking about the twist in the bar. Only the longer arms will cause it to be softer from less twist. Hell, I even confuse myself.

The moment would be the perpendicular distance from the shaft so I assume he meant the arm length.

How far can one of those be twisted before causing it to weaken anyway? For some reason I have 20 degree but I have no idea where I came up with that.

I was going through this project with a couple of the guys from a company that does metal heat treating for me.
They also do a lot of race car work.
They recomended a special alloy, AMS 6418.
They've seen this stuff twist 180% and come back.
I'm using it in a 3/4"x 45" shaft. The arms are 1/2"x 1.25" 8620 flat stock.
The links are super bling 3/4"x42" stainless steel hex stock I had laying around.

 

[Lincoln]

They recomended a special alloy, AMS 6418.
They've seen this stuff twist 180% and come back.

I'm guessing you won't be twisting it that far.

 

[Roxtar]

I'm guessing you won't be twisting it that far.

Not that bad but you might be surprised at how much.
I just mocked it up on CAD.
I can get one rear wheel 36" off the ground with the other three down.
Tires are about 63" apart (center to center)
The swaybar axle mounts are 44" apart
That equates to 25" of vertical separation where the swaybar axle mounts are.
That 25" of vertical separation on a 15" arc (length of the swaybar arms) = 98 degrees of twist.

 

[Lincoln]

Not that bad but you might be surprised at how much.
I just mocked it up on CAD.
I can get one rear wheel 36" off the ground with the other three down.
Tires are about 63" apart (center to center)
The swaybar axle mounts are 44" apart
That equates to 25" of vertical separation where the swaybar axle mounts are.
That 25" of vertical separation on a 15" arc (length of the swaybar arms) = 98 degrees of twist.

That's the reason I originally asked. You're just barely over 1/2 of the available, I think you should do something about that.

 

[Roxtar]

That's the reason I originally asked. You're just barely over 1/2 of the available, I think you should do something about that.

Lose the center limit strap?
Yea baby. That's what ahm talkin bout.