Flexing the 3 link (9 Viewers)

[scottryana]

Mine was a 3 link and it did brake evenly. Johnny joints on all joints, upper and lower. Maybe I am misunderstanding what you are saying but if you are saying that one side of the truck will dive down while the other doesn't? Yeah that did not happen.

 

[Booger weldz]

Dont get me wrong friend. I love your input and thoughts, otherwise this discussion would be boring.

I drop kids off at school, grocery shop, hardware store runs in these trucks. Icommute to work in them. I also drive them hundreds, thousands of miles to camp wheel.

Kids drive my trucks. Wifes drive my trucks. I text while driving my trucks, steering with my knee. There is merit
to my discussions that exist in the real world, beyond typing on the internet.

If you think you know more than me I welcome the knowledge/experience. I
love info and to make things better. If
you have something to share, please do so

I don't mind having a discussion with someone who understands simple geometry and forces booger. I've built and tested this stuff, so it's all first hand knowledge and not theories. It is yourself who needs help understanding. But I don't feel like wasting my time if your hell bent on argueing.

 

[4WheelUnderground]

Wasn't going to bother. But seeing as how you asked nicely. Firstly, 4WU's post above... Clearly you don't know much about superflex radius arms. I'm not for or against them. Stock radius arm seperation is 2x 185mm to control axle wrap. Binding is at its maximum as they are on a level plain. The same seperation verticly gives the least amount of binding with a radius arm design. But they handle like crap.

I SEEN ENOUGH OF THE FLEX ARM TO KNOW THAT ITS A GIMICK. ARE YOU SAYING BECAUSE THE BUSHINGS ARE MOUNTED ABOVE EACH OTHER RATHER THAN IN FRONT OF EACH OTHER THE HANDLING DOES TO CRAP? SO THIS MEANS THAT ALL OTHER RADIUS ARMS OUT THERE ARE COMPLETE CRAP? SORRY FOR THE CAPS JUST TRYING TO TAKE EACH COMPENT ONE AT A TIME AND TRYING TO MAKE EACH STATEMENT OF MINE VISIBLE FROM YOUR OWN.

Go ahead and unbolt 1 of the front radius arm bolts and take it for a drive. You will notice straight away that it dives down on unbolted side under braking. Because only 1 side of the axle wrap is now controlled. And there is a huge amount of rotational force twisting the other. I make this point because the same thing happens with a 3 link vertical separation. With the tower not centred and to 1 side. So in a perfect world the tower needs to be dead centre to control and disperse the forces equally to each side (when braking in a straight line). How ever braking when cornering, (even with a centred tower) unloads the forces from the cornering side and still happens although not as bad. This is why a parrallel 4 link with the same length links is far better for controlling this. Although binds more than the 3 link.


I HAVE HAD MY UPPER LINK ON BOTH SIDES OF THE AXLE, AND WHILE I DID NOTICE A SMALL DIFFERENCE IN BRAKING FROM SIDE TO SIDE THE LEAF SPRINGS I HAD WERE MUCH WORSE. WITH LEAVES MY TRUCK SHUDDERED DURING BRAKING AT LEAST COMPARED TO LINKS. THE LINKS DIDNT SHUDDER BUT HAD A VERY SMALL PULLING EFFECT. VERY SMALL.

Back to superflex. This is why the superflex arms still have 2 vertical bushes on 1 side. Yes they are closer, but to combat that 1 of the bushes is much smaller with much less bush deflection. So it still controls axle wrap and reduces binding just enough to allow for great travel. Which is the key to great on road and great offroad capabilities.

SORRY BUT I STILL HAVE TO SAY NAY ON THIS ONE. THAT SECOND BUSHING ON THE FLEX ARM SIDE DOES NOTHING BECAUSE ITS NOT BOLTED TO ANYTHING.

The pics I've seen for 4WU sets ups have varied heaps. 1 of a truck with 40 or 44" tires with no where near the correct amount of link seperation from upper to lower. 25% of tire size is minimal. Realistically 33% or 1/3rd is required. Then there are things that have been done (maybe it's just to get them to fit) but add undue stress to everything. Your lower links should never dissect higher than the axle instant centre. This creates more leverage and extra stress on bushes/towers. The same with not dissecting your coil perches to axle instant centres. Meaning they need to remain neutral and sit ontop of the housing. You've taken a force that's normal taken by the housing/tires, and now turned it into a 100% rotational force. Do you know how much force there would be when getting airborn with coil overs that are stepped off to the side of the housing/ or coil overs that are mounted onto the lower link arms as I've also seen somewhere. So much unnecessary rotational force a extra stress for no reason at all.

SO FIRST OFF PLEASE SHOW ME A PICTURE OF THE VHICLE YOU SPEAK OF THAT HAS MY KIT AND 44" TIRES. SECOND I DONT HAVE ANY COIL SPRING PERCHES. ONLY COILOVER MOUNTS. YOUR STATEMENT ABOVE READS " You've taken a force that's normal taken by the housing/tires, and now turned it into a 100% rotational force." I WISH I HAD READ THIS MORE CLOSELY THE FIRST TIME. BUT THE TIRES ARENT DOING ANYTHING FOR ROTATIONAL RESISTANCE IF THAT IS WHAT YOU MENT. THE AXLE IS ALWAYS TAKING 100% OF THE FORCE.

If its a 100% trail rig, you can do what ever and it doesn't matter. But what 90% of people are looking for is great on and offroad.

 

[4WheelUnderground]

The axle can not twist unless you break the axle tubes at the center section or break the upper link mount off.

The small amount of deflection there might be would be in the bushings.

Is it possible that one side will see higher compression forces during emergency breaking? Sure if your upper link is offset far to the outside and not angled from the inside of the frame. But even that would mean that the frame itself would have to twist up. Think about it, the cross members tie the sides of the frame together they don't allow one frame member to flex down and exert force without pulling the other side with it... Now tie the front of the frame together with a solid bumper, tie the middle of the frame together with a 3/8" thick skid plate and it becomes even less likely.

Its not the axle twisting under braking as many have thought its the braking force of the axle rotating the axle and transmitted through the frame that causes a difference in braking. Its the upper link pushing on the frame on one side of the truck and not the other. It has more to do with having anti dive of the geometry on one side of the truck and not the other. It has nothing to do with a twisting axle.

 

[Booger weldz]

Brian, call me, im awake and recovered from mothers day madness(brother brought moonshine @ 9 am).

 

[TheBigBoy]

Booger, your post is exactly why I wouldn't ever bother. Insult all you want.

 

[TheBigBoy]

Sorry 4WU. Just read your qouted message. Didn't see it until it expanded. The superflex arms aren't a "gimmick". Deflection from the bushings is what allows for the extra flex. You've reduced binding under suspension cycle. As where the 2 outer stock bushes on factory arms bind against each other, it has been removed on 1 side by making it vertical. When testing deflection of bushes, you pretend the rubber bushes are not there and it's only the bolts in the eyelets. And why I said the seperation on the vertical side is not 185mm as the factory was. They are closer together. However the upper bush is smaller and doesn't deflect as much = controllable axle wrap. Pics attatched. (Ps. Who is talking about leafs?)

 

[TheBigBoy]

As for the coil mounting position. I still think your not understanding me with that 1. Factory sits on top of the housing. So stationary, the weight of the truck (say 600kg per corner) sits ontop of the housing and transferred directly through the tire "straight down" there is NO rotational force. By stepping the coil over mounts to the rear of the housing, you've now added 600kg of rotational force to the link mounts (while stationary). The upper mount has more leverage, so it will be the lower that's taking a lot of force. And I appreciate that under braking forces this 600kg will be reduced. Having said that though jumping is a whole other story. Ontop of that the lower arms now dissect higher than the axle instant centre.

 

[Delancy]

otherwise this discussion would be boring.

Remember that...

The superflex arms aren't a "gimmick".

Agreed. They are not a gimmick and they have their merits, but as discussed a gazillion times, previously, and I'm not contesting anyone, they're not the end all to the 80 arm debate.

There's absolutely no way that a radius arm of any design or construction can maintain caster and a functioning front driveline angle on an AWD 80 series stock front housing.

It's geometrically impossible and, knowing what I know now (being that it ain't possible), that may have prompted a different path for yours truly, considering the expense required to correct both of the above.

The ROI isn't there when adding a
custom front drive shaft (or PT, which I can't stand), C&T, high steer, and other fab.

They're NOT a bolt on solution, as I've discovered, to anything more than increasing articulation, and create issues, as outlined fifty six million times, that may negate benefit.

Want what most all want and was/am prepared to pay dearly for:

A 3-4" lifted, 2.5 ton, station wagon-rock donkey that rides better than a Lexus, handles like a stocker, doesn't require a Dramamine script, nor moisten the panties of female occupants, all while maintaining resemblance to OE roots.

Yet, there's nothing available to achieve and lack the skill set to DIY the impossible.

 

[scotia]

Once again....The 80 series front end debate...just agree to disagree and run whatever the heck you want...you can have all the math to back up your views, but it's still all subjective. Math make make it correct on paper but not by the end user.I want mine to be street able granted it only gets a few K miles a year. I enjoy not having a trailer queen and I can handle what comes with the modified front. If not, my truck would still be stock and it is far from that. My 2 cents as with most aforementioned posts.

 

[Booger weldz]

Booger, your post is exactly why I wouldn't ever bother. Insult all you want.

I edited it, sorry.

Still need some discussion outta you that warrants your original 4wu comment. So far, your just another keyboard jockey w no welding burns or grinding wheel scars.

 

[Booger weldz]

Is this discussion about flex via smashed bushings or the fact that radius arms cause cause horrible road manners in the orientation you keep mentioning? Ill take stock arms remounted above the axle any day over what your describing. You havent addressed anything with that setup except loosened up the connection to the chassis.

Sorry 4WU. Just read your qouted message. Didn't see it until it expanded. The superflex arms aren't a "gimmick". Deflection from the bushings is what allows for the extra flex. You've reduced binding under suspension cycle. As where the 2 outer stock bushes on factory arms bind against each other, it has been removed on 1 side by making it vertical. When testing deflection of bushes, you pretend the rubber bushes are not there and it's only the bolts in the eyelets. And why I said the seperation on the vertical side is not 185mm as the factory was. They are closer together. However the upper bush is smaller and doesn't deflect as much = controllable axle wrap. Pics attatched. (Ps. Who is talking about leafs?)

 

[nukegoat]

I don't remember writing that. Can you please copy and paste the section you're speaking of? From what I remember it isn't a non-parallel 4link that is a glorified radius arm its 4 equal length uppers and lowers that are parallel that are. If all arms are equal length and parallel then during articulation one side of the axle is twisting against the other. If I failed to make that clear to the reader then I certainly take blame for it. Sorry in advance.

From your website:

"The Four-Link + panhard bar which is also referred to as a “Five-Link” by the OEM’s, uses two uppers, two lowers and a panhard bar. Unlike the three-link, which has the upper and lower converging at some point, the four-link’s upper and lowers are of equal length and parallel to each other. Without this key ingredient the four-link is a glorified version of the radius arm system."

 

[nukegoat]

The only problem with that kind of kinematics you speak of is that they don't take in to consideration the terrain you're on isn't level to the earth. Going up a 50* hill changes things drastically! For example, I've helped friends dial in their geometry suspension designs on various other rigs and I've always gotten their rigs to climb better with less anti squat then more. Which is a total opposite to most road course racing or drag. My only point is that dynamics change when the terrain changes. Building geometry for terrain that is never the same is not the same as consistently flat black top.

Good point and I agree. I'm simply stating that there is more info out there for those who wish to learn more. Reading more about suspension engineering isn't going to hurt anyone who's serious about this endeavour.

 

[Booger weldz]

Reading more about suspension engineering isn't going to hurt anyone who's serious about this endeavour.

Unless your reading this thread, lol!

 

[nukegoat]

Once again....The 80 series front end debate...just agree to disagree and run whatever the heck you want...you can have all the math to back up your views, but it's still all subjective. Math make make it correct on paper but not by the end user.I want mine to be street able granted it only gets a few K miles a year. I enjoy not having a trailer queen and I can handle what comes with the modified front. If not, my truck would still be stock and it is far from that. My 2 cents as with most aforementioned posts.

The math is only wrong if the assumptions that went into the calculations are wrong. Not saying you're taking it this far, but this is the attitude that I can't stand on Pirate (and here, to a lesser extent) - there's this anti-academic sentiment that goes something like

"Brah, I've been weldin and racin and crawlin and muddin for years n brah i know somethin bout dem suspension without all your fancy book learnin and your calculators and computers and whizbangerry and i will put my blazer with my boggers up against yer trash rig with all its science any day cause let the best rig win and theres no substitute for rawdog experience brah"

 

[nukegoat]

Unless your reading this thread, lol!

I could use your help selecting coilovers, btw. I'm at a loss there

 

[Booger weldz]

I could use your help selecting coilovers, btw. I'm at a loss there

Red, blue or black. Pick you favorite color. Just dont try and save a few dollars @ FOA. The potential for headaches far outweighs the $ saved.

FOA doesnt mean 'First Over All'. Its 'Fxxxing Oil Allover'

 

[nukegoat]

Red, blue or black. Pick you favorite color. Just dont try and save a few dollars @ FOA. The potential for headaches far outweighs the $ saved.

FOA doesnt mean 'First Over All'. Its 'Fxxxing Oil Allover'

Bummer. What about spring rates / lengths? I assume you just have to experiment with shock valving after you select your springs?

 

[DHwreckage]

Red, blue or black. Pick you favorite color. Just dont try and save a few dollars @ FOA. The potential for headaches far outweighs the $ saved.

FOA doesnt mean 'First Over All'. Its 'Fxxxing Oil Allover'

just one thought on the above they are all pretty much the same (red,blue, baby blue or black) but the icon's (black) have some better rod coatings then the others so if you live in a corrosive environment i.e. salted roads i would go with the icons. otherwise they're all basically the same!