Flexy Coils and Mathematical Theory for Review

[kbahus]

Thanks for the explanation on the sway bar issue. My tired and blood shot eyes skipped right over the flex restriction part. How do you think a stiffer sway bar would affect a truck with say a 2" lift? Since a 2" lift is not going to flex like the taller lifts would it limit flex even more?

I think a lot of people are after what Delancy is looking for:

"Guess the mentality is flawed, but wanted low to keep stable, yet free up articulation to make it crawl over anything."

 

[Delancy]

Thanks for the explanation on the sway bar issue. My tired and blood shot eyes skipped right over the flex restriction part.

Here's the deal though.

Some anti sway and restriction is necessary to force the fronts pliability, in my opinion, unless on a ramp.

My justification for pursuing anti sway options isn't solely for on road or off camber stability, but to make the front do a little work, too.

Even with the SE arms that, in theory (yet remains to be proven with longer shocks), allow for more articulation than the OEs, the most variation I can get from one side to the other (using jack stands and gravity, WITHOUT the vehicles weight, which is a huge component and why I've not eluded to the before) is 4" with the DS being 5" lower than PS.

That's really an irrelevant dimension, because its missing a huge factor being 1/2 of the 5500lb vehicle, but based on seeing what little it possible with the short shocks I have, that, in my idiot observation, put the coils into a bind sooner than what longer shocks will, there's nothing to force the front to move, except the coils against the frame and gravity.

I haven't slept in a Holiday Inn in sometime, for the record.

How do you think a stiffer sway bar would affect a truck with say a 2" lift? Since a 2" lift is not going to flex like the taller lifts would it limit flex even more?

All my references are to a rear only on a 80 that a front sway isn't an option, and my opinion here is exactly that, opinion.

I don't think at 2" the sway negatively impacts enough to warrant a change, personally.

The front, in my opinion, being removed off road is a must, but (short of the low hanging arms) don't think there's much that could be improved by stiffening the bar.

 

[AutoCraft Aus]

Its one of those things that really need to try, to understand, because what it does, isnt what you expect.

It works well on a 2" lift, I had the heaviest on my lightest rear 80, just to try it, when we had the first 180% ones made, and I couldn't believe how much the car body stayed still, and the axle did all the moving.

A classis example of this was the first time we slipped the 4wd button in.

Driving a very soft sand beach, normally crossing over the big worn grooves of wheel tracks at an angle the car will pitch corner to corner, causing you to hit your head on the roof lining edge where it meets the door.

The body stayed dead flat, the axles did all the up and down.

Similar thing happens at crawl speed.

It also helps prevent roll steer in the rear, by preventing the lean, that makes a changing wheelbase as the rear arms work in an arc.

 

[Delancy]

180%?!?!

Man, I've gotten no help from any bar producers either, and I'm fine with that, because I can oversize and turn down locally, but I was thinking 135% max.

My calcs.

.938" bar

19" arms

43" effective length

57lbs/inch effective rate at arm ends.


Not sure if the entire length, including what goes around pumpkin (adds 1.25") should be considered, or not, but a nominal difference.

 

[AutoCraft Aus]

So now you have the sway bar itself sorted mathematically, what have you worked out the car needs ?

 

[Delancy]

So now you have the sway bar itself sorted mathematically, what have you worked out the car needs ?

That's the variable that hasn't been determined and no one can say, or is at liberty to say.

Basing, to some degree off Whitelines HD bar that y'all seem to love (offroad80)

If a Whiteline HD is 20% stiffer than stock, need a bar with an effective rate of 69lbs/inch.

Bar length- 46.75"

Arm length - 18"

Solid Bar Diameter-1"

Equates to 70lbs per inch.

BUT

here's the catch to that.

Have a 50"x1" Currie bar with 21" arms and it equates to half of that at 50lbs/in.

Now, I KNOW it ain't enough for the 80, but not sure it the 80 warrants a bar that's effective rate at arm end is ~30% more.

 

[Delancy]

Right now, butt dyno says it needs A LOT, but these arrived









And charged, they're friggin' stiff.

Put the OMEs on without a jack. That ain't happening with these.

 

[Delancy]

A question.

Are the guys in OZ putting the Whiteline HD bar on the rear with a front sway, too?

 

[AutoCraft Aus]

We normally keep the front std one.

We add a rear heavier one.

We don't use the whiteline ones, they are cheaper, but we don't like to move away from factory bushes/rubbers etc, I have trialled the Whiteline ones in the past.

We do have heavier fronts, mainly for the towing brigade, to keep the car flat on the road, when loaded heavy, and towing heavy, to stop them wandering.

 

[Delancy]

Then the comparison is flawed.

Has to be stiffer than the OE on mine, but I'm unsure by what percentage.

 

[AutoCraft Aus]

We use the 130's for rear bar and carrier.

We use the 180's for full heavy twin wheel carriers, rear l r tank, roof rack etc, normally.

Ramp difference with more weight is negligible.

front we do is 180 as well.

Have you tightened all your arms and panhards at 3/4 droop when you work on the truck, so the bushes droop easily, but are forced to twist on compression ?

 

[Delancy]

We use the 130's

We use the 180's

And that's 180% of OE sway bar rate, correct?

Have you tightened all your arms and panhards at 3/4 droop when you work on the truck, so the bushes droop easily, but are forced to twist on compression ?

Of course....not. First I've heard of.

Don't recall that procedure in the FSM. Haha.

You're talking at the rod ends, right?

 

[AutoCraft Aus]

yep.

And yep, all bolts for all moving arms.

When your being as pedantic as you are for flex, every extra 1" helps.

 

[kbahus]

Here is Whiteline's sway bar conversion chart and they make both a 27mm and 30mm rear bar.

http://www.whiteline.com.au/docs/bulletins/BL-281.pdf

I have a pretty good hook up for Whiteline products through the shop I work for. We sell tons of Whiteline stuff on the Subaru/Mitsu market and I have used their products for a good decade with good results. Now that they have a full line of parts for the 80 I have been contemplating ordering some arms and a rear bar. If that rear bar does as much as Darren says my rig should benefit from it, especially when I am full of gear for a weekend trip. I also run a front disconnect system when offroad, but lately I have been too lazy to pull the pins.

Darren, when your truck gets it's head gasket replaced I would love to drive down and meet you as well as check out the rig.

 

[js93cruiser]

I love my whiteline away bar, it helps a ton?

 

[js93cruiser]

!!!!!!*

 

[TheBigBoy]

It depends who you talk to I guess. Thats what you do darren, not everyone else. 99% of the people I know run NO front sway bar at all. And a whiteline HD rear with great success.

 

[AutoCraft Aus]

It depends who you talk to I guess. Thats what you do darren, not everyone else. 99% of the people I know run NO front sway bar at all. And a whiteline HD rear with great success.

We, well I wasn't including you, been talking as the name we signed up as, and you don't get in here, so....

Shotts used to have the same fuzzy logic about travel vs length, and as much as he was the only one to have a smilie named after him,


Im tipping your going to end up No 2

 

[AutoCraft Aus]

Darren, when your truck gets it's head gasket replaced I would love to drive down and meet you as well as check out the rig.

No problem, going to need some destinations to go wheeling, and events to attend too, while its over there.

We did Cruise Moab this year [about to detail that in my build thread in my sig line] as well as camped in the Grand Canyon, Seligman to Bullhead on old Route 66, VORE in Vegas, and back to Slee Offroad, last trip.

Looking at best way to swap/fix/convert SNOWY right now, and happy for anyone to come drive it, I am going to send sway bar, and some other stuff, and the rear shocks are back at ICON for a rebound adjustment ATM, and we have neg camber, plenty of caster, ideally setting it up to drive really nice, shocks should be back before the HG is completed, which ever way I go.

Need a low mile 4.5 to bolt in, easy option

Unless there is a sc one kicking around

 

[TheBigBoy]

You are forever dropping names and dates. 1 wouldnt have to do much to look clever standing next to you. Your talking about "us" who is "us". I hope your not representing most of OZ geeeez. You act and think you know everything. You didnt even know caster till a few months ago - since 2002 pffft. Thought you would have learnt something by now. Chris is in real trouble if he starts listening to you. lol