Front Flex? (1 Viewer)

[Nay]

That's a crock. Too heavy to be on all coils? It's all a matter of doing it properly. I've seen a few monster trucks on all coils do well. Also have buggies around here that weigh every bit as much as my 80 running on coils - lots of 44+ tires on buggies and jeeps around here, very few leaves

OK, I'll qualify, it's not really a pure weight issue, but weight in relation to suspension design. The 80 has fairly short coils. As lift goes up, road performance is maintained by significant increases in spring rate, which means that lifting an 80 does not gain a lot of full extension coil length.

Without a lot of additional coil length, it is very difficult to design extra shock travel to move without the sweet spot of the coil if you want a long travel suspension. This is why, for example, FOR is using a shock that is slightly shorter than OME medium on a 4" lift, despite the progressive design of the coils.

Another way of saying this is that the travel of an 80 series coil becomes increasingly unmatched to the desire to create a long travel suspension the more you lift, which is atypical for a crawling rig where lift usually allows a lot more "sprung" suspension travel because you get progressively longer coils. This is why I say the 80 is "too heavy for coils" when you have a long travel design goal.

Slee is not a novice - it would be simple to replace the L shocks on his 6" lift, but this would likely be accompanied by much of the suspension travel being completely unsprung on the droop end. This is not a good design goal, and it is a complication of going big on an 80.

The 80 isn't a buggy - it's a dual purpose rig where for almost every user road comes first. Nobody has solved the issue of load bearing requirements vs. long travel in an optimal way yet. Nobody. FOR IMO represents the best compromise of those two requirements, but that kit does not make an 80 a rock monster. It simply optimizes what the 80 really is.

 

[Walking Eagle]

But, they have flex bushings in the arms. Doesn't that help?

Chris

they have stock Toyota bushings, or optional poly bushings - nothing special or flex oriented

 

[Walking Eagle]

Nobody has talked about the coils, as far as how to retain them, if the front flex could be improved. Slee said before regarding Action Jackson's 3-link that the coils won't like the forced compression from a longevity standpoint. and capturing them in the upper coil cone would have to be considered.
!

Guess I'm nobody, cause in my first post I said the problem is none of the readily available coils have enough extension to stay seated.

 

[Nay]

The same reason you gain flex pulling one of the bolts. Also the same reason dropped arms flex better than stock mount - it's the different paths of the DS and PS that are creating the bind. It's also why Y link radius arms flex better, well, at least part of it. The axle twists forward and backward as well, and if there is a mount to the front and back of the axle, that its going to resist that movement more than if it has two mounts in line behind the axle. Even better yet if those two mounts are set up to be the same distance from the arm mount.

I see it now. One side will move in a way that would bind fore/aft in the stock setup, but the other is moving on a different plane so they aren't working against each other. Putting both arms in the new design would probably only alter the binding direction for the most part.

You are still going to get the restrictions of the narrow arm mounts and small bushings, but that is probably a good thing in that it keeps a degree of restricted stability in the system while relieving that massive amount of bind designed into the stock system.

SE has already responded to my inquiry and are going to quote with shipping. I'll post up.

 

[ravencr]

they have stock Toyota bushings, or optional poly bushings - nothing special or flex oriented

Oh I guess I thought they had jj or re style joints in them. Guess I should have read more...lol.

Chris

 

[Bikeman]

Yea, sorry, Walking Eagle, I thought you were talking mainly about the rear.

 

[Nay]

they have stock Toyota bushings, or optional poly bushings - nothing special or flex oriented

Right, the flex would come from the alteration of the mounts on one side of the axle reducing the pure fore/aft bushing bind.

 

[Nay]

Oh I guess I thought they had jj or re style joints in them. Guess I should have read more...lol.

Chris

A JJ would bind like hell, because the bushing could not compress. You would literally rip the mounts off the axle the first time you went wheeling.

You can only use spherical ball joints in a 3 link at all mount points for a standard arm/link suspension.

 

[ravencr]

Sounds like I have a lot to learn on this vehicle.

Chris

 

[Nay]

Sounds like I have a lot to learn on this vehicle.

Chris

The bind on the front end comes from the bushing mount placement, small bushing, and narrow mount.

As the front end droops, the arm on the droop side has to pull backwards in an arc while the compression arm has to push forward in the same arc (on a lifted rig, anyway). This means the axle has to shift fore/aft, and the bushings have to compress fore/aft in those small radius arm mounts.

Small bushings = little available movement, especially when both mounts are on the same plane, unlike a Y-link radius arm setup or a typical Jeep 4 link.

The usual issue with bushings is a limitation on how much they can twist, hence the consistent application of johnny joints in the Jeep world to relieve the bushing requirement of excessive twist (and Jeep does not have a rubber bushing design such as in the 80 series rear arms that can durably handle a lot of twist).

But no matter how you mount the arms to the axle, you cannot create a rigid mount at four points in any design by using spherical joints, because all typical suspension links create fore/aft movement of the axle, including arched leaf springs. If you have four rigid mounts, you can't move fore/aft, and you are going to have problems because the axle cannot droop in a pure perpendicular arc to the body.

This is why Jeep y-link radius arm conversions use a johnny joint at the frame and rubber on all of the axle mounts - the frame mount handles the twist and the big rubber axle bushings only have to accommodate the fore/aft bushing deflection.

That is also why you can design a 3 link with johnny joints at every mount - the side with only one mount can act purely as a pivot point and you literally have no mount bind in the system.

There is no reason for a 3-link to be unstable just because of one less axle mount - the reason it works poorly on the 80 onroad is the rear is already very flexy and you have 2 tons of sprung weight flying around on a completely unrestricted link/coil system.

The 80 lacks easy answers but mostly it doesn't need them because you can stay "in the box" easily on 37" tires. A typical Jeep gets out of the box on 33's (until the Rubicon anyway).

These SE arms are interesting...

 

[Walking Eagle]

OK, I'll qualify, it's not really a pure weight issue, but weight in relation to suspension design. The 80 has fairly short coils. As lift goes up, road performance is maintained by significant increases in spring rate, which means that lifting an 80 does not gain a lot of full extension coil length..

Significant increases in spring rate are not the only way of maintaining road performance. It might be the easy way, it's not the only way. Besides, akarilo isn't that high, and you don't have to go higher to gain a little flex.

Without a lot of additional coil length, it is very difficult to design extra shock travel to move without the sweet spot of the coil if you want a long travel suspension. This is why, for example, FOR is using a shock that is slightly shorter than OME medium on a 4" lift, despite the progressive design of the coils.

Yep, coil length can become an issue - which I said in my first post in the subject

Another way of saying this is that the travel of an 80 series coil becomes increasingly unmatched to the desire to create a long travel suspension the more you lift, which is atypical for a crawling rig where lift usually allows a lot more "sprung" suspension travel because you get progressively longer coils. This is why I say the 80 is "too heavy for coils" when you have a long travel design goal.

There is a difference between trying to get an 80 to have a long travel suspension set-up and trying to get a little more flex out of the front. Don't know akarilo's goals, but they sound simular to mine, get the front to flex a bit more, not become a floppy mess.

Slee is not a novice - it would be simple to replace the L shocks on his 6" lift, but this would likely be accompanied by much of the suspension travel being completely unsprung on the droop end. This is not a good design goal, and it is a complication of going big on an 80..

Any 6" lift that uses OME L shocks is a joke pure and simple.

The 80 isn't a buggy - it's a dual purpose rig where for almost every user road comes first. Nobody has solved the issue of load bearing requirements vs. long travel in an optimal way yet. Nobody. FOR IMO represents the best compromise of those two requirements, but that kit does not make an 80 a rock monster. It simply optimizes what the 80 really is.

Yes, Nay, and there is no reason to go beyond 35's on an 80, and 5.29's are perfect for 35's, and blah blah blah. Nothing is static. Not your view on what you want to do with your 80, nor anyone elses view, nor the technology that is out there to make them work. A decade ago you couldn't get 14" travel shocks. A couple years ago shocks with the capacity of my XL's were unheard of. Just a few short months ago air bumps were an expensive pre-runner and race only component - now there are two different companies offering advanced bumpstops, who knows what we'll have tomorrow.

I haven't seen any 80's with torsion bar swaybars yet - they may be out there, but I haven't seen them yet (you know, currie anti-rock or the like). Also don't see alot of people putting heavy duty swaybars on to manage on road. It seems more common that peole just give up and take them off all together and then claim they drive fine on the hwy.

There is nothing wrong with trying to get a little more out of the front end, and getting a little more out of the front end doesn't have to mean super long travel and uncontroled bouncing. It's just takes more planning, more thought, and more experimenting than just going off the shelf.

 

[Hayes]

I am going to try the front sway removal, as I used to run the SAS 4runner that way. Does anybody daily drive without the front sway? I'm not into the dissconnect thing to go wheeling.

I still run my front sway when not wheeling.
I replaced the bolts at the axle end of the swaybar with spring-retained pins. I welded some simple retainer brackets (drilled out angle iron) above that point on the frame. When I'm going wheeling I unpin the front bar from the axle and pin the ends up against the frame, out of the way.

Remember, the key is leaving the rear antisway bar on. It forces the front end to move more. Doesn't increase total travel or articulation, but it frees it up.

Nay also makes a good point about the axle end mounts breaking off during articulation, causing the antisway bar end to take out the nearby brake line. It has happened.

Tapage. That gear looks friggin' cool.

8' ledge. White Knuckle. That's got to be pretty close to 8'. There are photos around here of 80's going down that. Pretty much a bash-fest.

80s are all about bashing, with grace.

 

[Nay]

There is nothing wrong with trying to get a little more out of the front end, and getting a little more out of the front end doesn't have to mean super long travel and uncontroled bouncing. It's just takes more planning, more thought, and more experimenting than just going off the shelf.

It's good to have you back around so we can talk about something besides OCD Blackstone oil reports

Of course there is nothing wrong with trying to get more out of the front end. If I can bolt on a reasonably priced set of SE arms and get the full travel out of my current setup and add comfort offroad without any negative onroad impacts, that's pretty damn golden.

The point of my posts isn't to discourage any type of innovation, it's to help ground expectations that there is very little you can do to make an 80 much more than it is in net trail capability without turning it into a beater. Trying to solve the operator error of driving off of ledges sideways by modifying the front end is a poor recommendation .

The size of an 80, it's weight, the low hanging frame, the inability to easily reduce the low range, these are all substantially more compromising factors than the level of flex in the front arms, and adding flex does nothing to address them but can come with significant issues. Should our OP really cut off one of his axle mounts to add a little bit of flex when he relies on his 80 as safe family transportation? What happens if that single mount fails at 70 mph?

Having said this, conventional wisdom is usually crap. This forum was of a total belief 4 years ago that you needed a 5" lift to properly run 35's. I called BS then and I now run a suspension 1.5" lower on 37's that completely and utterly disproves that idea - these thing are simply inevitable because they have been done before and there is no magic about a Land Cruiser suspension. Sure, I had to tune a little bit, but tuning is not a compromise. Tuning is optimizing.

I would be the first guy to redesign the front end if I thought it was critical. I have easy access to a slew of excellent fabrication shops and fabrication is far cheaper and more effective than high price/low volume 80 series bolt on accessories.

For me, any loss of road capability is a terrible exchange for an extra couple inches of front end flex. The 80 is so great because you can drive around on 37" MT's like they are 33's, and that is because of the front end design. Most re-engineering mods on a dual purpose rig are trading one problem for another, usually worse, problem.

Which is why almost every truly re-engineered 80 we have seen has been sold, and the 4" lifted 35" shod 80's abound like breeding rabbits.

 

[Hayes]

Also don't see alot of people putting heavy duty swaybars on to manage on road.

I asked around here a couple years ago about this one. Would an HD swaybar up front help with body roll on the highway? I already disconnect mine off road, so there would be no harm to my off-road manners.

Nobody seemed to think it was a good idea.

 

[silverhorse]

Anybody thought of plain old simple leaf springs??
They are Stable and have the ability to flex great if done properly.

 

[pr0ject42]

You won't be getting away with leaf springs on an FJ80 front axle, or at least and keep it safely streetable. The steering setup doesn't jive with leafs, ask the mini-truck guys who have been trying to put 80 axles under the fronts of their rigs. Their answer is either a 3-link setup or a z-link for the draglink

Anybody thought of plain old simple leaf springs??
They are Stable and have the ability to flex great if done properly.

 

[silverhorse]

Then they should use everything from a mini or 60.

 

[sleeoffroad]

I haven't seen any 80's with torsion bar swaybars yet - they may be out there, but I haven't seen them yet (you know, currie anti-rock or the like). Also don't see alot of people putting heavy duty swaybars on to manage on road.

We do get a lot of calls on heavier swaybars. The trend is that they blow out the bushings pretty quick if a upgraded bar is used in the stock locations.

I have never seen anyone try to retro a Currie or similar swaybar to the 80. What I have seen is a bunch of broken links on those swaybars when people wheel them.

 

[ravencr]

Christo,

Is there anything you've done to your 6" lifts to make them flex better, whether it be custom or bolt on? Different shock mounting locations, shocks, bushings, etc?

Chris

 

[sleeoffroad]

Unless you start changing links, you are pretty much stuck with what you got. Most of what can be done has been covered in this thread.

This is essentially a stock 80 suspension setup with long travel shocks and shock mount positions moved. These were 14" (I think) travel Rancho shocks with both the front and rear top shock mount positions moved upwards so that we had place for them to compress. This was running about 4" of springs, captured on top and the bottom. Obviously no swaybars, but I think this shows have far the link setup can be pushed if need be.

We do have bolt in shocks that are 2" longer than OME that we offer to people. We do not include them standard due to limited supply and people need to make sure with a longer shock that you do not over compress as well as make sure the spring does not become unseated. That is why we do not list them with the kit. We also have access to these direct bolt in shocks that have swivel pins at the ends to ensure that there is no side loading on the pins. However they are a pretty high $ option. These are the same shocks that Ben ran on his XRRA racing truck last year. We did the testing on that truck to determine reliability.