Quarter Elliptical Tech

[XJ_ranger]

those are all for dampning, the spring rate comes from a torsion bar.

right, but if you mounted coilovers there instead of shocks... then you'd get both....

 

[Weasel]

Spring rate with the bag and spring pack would be similar to a dual rate spring or two springs in series. Although if the bag is only active in a certain area of travel, two different models might be looked at. And there is a way to determine spring rate for a 1/4 pack, should dig around and see if I can find it.

I like the 1/4 setup as well but the only drawback I can see is it seem like more wieght then coilovers or air shocks. Think I have a way to elivate it but gonna have to wait till I get a real job.

 

[BrettM]

I like the 1/4 setup as well but the only drawback I can see is it seem like more wieght then coilovers or air shocks.

that's the one reason I didn't do 1/4 elip when i linked the rear of mine. a single leafpack must weight 5 times what a pair of plain coils weighs.

 

[CRASH]

Thought of the cantilevered CO idea, there is room to make it work, but the packaging gets awfully complicated. The beauty of the QE packs is there simplicity, I'm hesitant to even put the airbags in the system, as they add complexity. I haven't had to fix my junk very often on the trail in the last several years, and I attribute that to simple, bulletproof systems.

Rich, I'm not gonna cut the Nationals. Hell, I could sell the Nationals and fund this whole stupid idea. Maybe i should just keep the Nationals as they are, eh?

Greg, what is the length of your QE pack? Seems like it needs to be longer than the front half of an OEM pack, but maybe not if I did it Similar to OneHub, mount the shackle behind the axle (what I had in mind anyway).

Brett, a double torsion bar setup could be made to work, but I'm not sure you'd have enough length (or in this case, frame width) to have enough travel in the bar without excessive fatiguing of the bar. Most IFS trucks run a very long bar, like 4 ft or longer, to achieve adequate spring rate and travel, yet VW's run a shorter bar, but are much lighter. Maybe it can be done.......Check out these spring rates and max degrees of twist (Sway-A-Way):

Torsion Bars Parts (In LB/Degree Of Twist)
Bar Diameter / 1000 Series 21 3/4" / 1100 Series 24 11/16" / 1200 Series
26 9/16"

20mm 401 339 317
21mm 488 413 385
22mm 588 497 464
23mm 702 593 554
24mm 832 703 657
25mm 979 828 773
26mm 1145 968 904
27mm 1333 1126 1052
28mm 1651 1303 1217
29mm 1774 1499 1400
30mm 2031 1716 1603
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Torsion Bars Maximum Angle Of Twist For Racing Bars
Bar Diameter / 1000 Series 21 3/4" / 1100 Series 24 11/16" / 1200 Series 26 9/16"

23mm 41.4° 47.7° 51.7°
24mm 39.6° 45.6° 49.5°
25mm 38.0° 43.8° 47.5°
26mm 36.5° 42.1° 45.7°
27mm 35.2° 40.6° 44.0°
28mm 34.0° 39.2° 42.5°
29mm 32.8° 37.8° 41.0°
30mm 31.7° 36.5° 39.6°

 

[CRASH]

Check out the interactive spring calculator on Sway-Away's page: http://www.swayaway.com/Suspension Frameset.htm

 

[C-ROK]

Greg, what is the length of your QE pack? Seems like it needs to be longer than the front half of an OEM pack, but maybe not if I did it Similar to OneHub, mount the shackle behind the axle (what I had in mind anyway).

My longest leaf is the Cherokee main. Remember it's got an offset center pin by about 2" or so from the true spring center.
I retain the pack with two bolts. The front bolt is about where the center pin would have been.

 

[Dirk Pitt]

I'm being ultra lazy tonight. If it's been covered I don't care.

OneTon made a bracket to capture the ends of the springs and I believe a heim on the axle end so the springs didn't get hit with as much twisting force.

Can barely see them in this pic.

If you went the coil route you could always use my setup and stuff some of those cheap bags on the inside. Mine are rated to 500 lbs each at 30 psi with 5 lb minimum. It does provide somewhat of a progressive rate though.

The problem I was having was finding room for everthing once the links were in. I've been looking at it again and thinking about 1/4's or even keeping my coils and making those work. Exhaust is going to be a bit** no matter what.

I like the Beezil/OneTon design but these will help some with leaf twist.

http://www.deaverspring.com/BajaBushing.htm

 

[Jeff 98XJ WI]

Have you looked at Bigwoody's old MJ? I know he used 1/4 elliptic springs. I wonder what he used for the springs and how happy he was with them. He must have some input. Jeff

http://smg.photobucket.com/albums/v478/gmanstone/?start=100

 

[BIGWOODY]

Not to step on toes, but I personally think a lot of you over think this. You aren't building something to go into space with and most everyones rig and driving style is different, so there isn't going to be one "good for all" formula. I used STOCK Mj rear spring and cut them up, I used a rock equipment sway bar and a sorta "standard" double triangulated link set up. We built it all in a few days, never had to change anything, and didn't buy a bunch of expensive crap. I hinged mine at the "frame" end and a re-worked stock shackel on the axle.

 

[CRASH]

Not to step on toes, but I personally think a lot of you over think this. You aren't building something to go into space with and most everyones rig and driving style is different, so there isn't going to be one "good for all" formula. I used STOCK Mj rear spring and cut them up, I used a rock equipment sway bar and a sorta "standard" double triangulated link set up. We built it all in a few days, never had to change anything, and didn't buy a bunch of expensive crap. I hinged mine at the "frame" end and a re-worked stock shackel on the axle.

There is no such thing, in my opinion, as overthinking a suspension design.

Well, perhaps if a had a rig that lived on a trailer, had plenty of time for re-doing spring rates, and didn't care about cutting up my body to make it fit, then I guess I wouldn't think about it at all, and it would be done already.

But, when you drive your rig to the trails, some hundreds of miles away, with your family inside, you tend to want your rig to perform reasonably well on, and off road, the first time.

Plus, I'm a nerd, and like to engineer solutions rather than bodge them together.

 

[Roxtar]

the work is already done - Andy himself showed us the thread -
http://www.naxja.org/forum/showthread.php?t=70338

.... :stir: :stir:

Whew!
For a minute there, I was afraid it'd be complicated.

 

[CRASH]

Whew!
For a minute there, I was afraid it'd be complicated.

That picture makes me moist.

 

[BIGWOODY]

But, when you drive your rig to the trails, some hundreds of miles away, with your family inside, you tend to want your rig to perform reasonably well on, and off road, the first time.

Plus, I'm a nerd, and like to engineer solutions rather than bodge them together.

I understand what you mean, but just for the record I drove my MJ over 100miles to the trail with the air running and doing 75-80mph on the highway on its first trip out...then it became a trailer bitch. The buggy of mine now will be street legal in NC and will be road driven quite a bit on weekend trips to the ice cream shop, I wouldn't have anything that could be driven at above 60mph on the road.......

 

[Roxtar]

That picture makes me moist.

Tell me bout it.
The thread where that picture came from gave me wood for a week.

 

[Goatman]

Whew!
For a minute there, I was afraid it'd be complicated.

That picture makes me moist.

I'm diggin' the flow though reservoirs and the way the air bumps work off the cantilevered arm.........on top of the whole bad ass leverage system.

I wonder who's kit that is?

 

[David Taylor]

I wonder who's kit that is?

I see a new URF bolt on kit coming soon. The "half your spring eliminator kit"

 

[NXJ]

Why mess with that ancient leaf-technology? I'd say go full air - adjustable spring-rate and ride-height, geniusly.

How about a set of AiROCK-bellows?

 

[CRASH]

For the reasons discussed in this thread.

Did you read the thread?

 

[JeepFreak21]

BIGWOODY,
When you say it hinges, do you mean like this? Got any pics of the hinging action?

Billy

 

[C-ROK]

Why mess with that ancient leaf-technology? I'd say go full air - adjustable spring-rate and ride-height, geniusly.

How about a set of AiROCK-bellows?

Wonder where AirROCK get's 'their' air bags from? My guess; Firestone, the manufacturer discussed at the begining of the thread.
Total travel range with air bags alone is also relatively limited.
You're correct about spring rate and ride height. That is their appeal.

Quarter elips really just started appearing in trophy trucks about a decade or so ago at most. I don't know how 'young' you'd need to be to consider that "ancient".
Some would also consider 'old technology' to be well proven. A virtue not to be dismissed lightly just because some new fad comes along.