SpaceGhost
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Four Link Frnt End (1 Viewer)
- Thread starter dacicci
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- #22
that is sweet i like that i may do mine that way
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- #23
update a little slow trying to juggle working on this and working period. this is with the suspesion almost completely compressed about 6" up more. starting rear tube work next weekend should make toys for tots this year
Last edited:
Hi everybody! 
I'm going to convert my FJ from SPOA leaf springs to coil springs, but I still have some doubts about the work:
a lot of people suggested me to utilize, at least on the rear axle, the four link to increase the excursion.
That system is surely performing, but involves also a lot of building problems, expecially calculating the squat (I calculated that I should low my car to obtain a positive squat).
Lokking at the front axle of SpaceGhost's car, that seems to be a panhard, I noticed that I can have a good mobility of the suspension even with a simple panhard: is that true? I have to say that I dont' want one meter of excursion, I don't have to do any ramp contest!
I just want a suspension kit a little bit more performing of the leaf spring that I have now.
Another thing: with panhard I don't have to calculate squat/antisuqat, isn't it?
Francesco
I'm going to convert my FJ from SPOA leaf springs to coil springs, but I still have some doubts about the work:
a lot of people suggested me to utilize, at least on the rear axle, the four link to increase the excursion.
That system is surely performing, but involves also a lot of building problems, expecially calculating the squat (I calculated that I should low my car to obtain a positive squat).
Lokking at the front axle of SpaceGhost's car, that seems to be a panhard, I noticed that I can have a good mobility of the suspension even with a simple panhard: is that true? I have to say that I dont' want one meter of excursion, I don't have to do any ramp contest!
I just want a suspension kit a little bit more performing of the leaf spring that I have now.Another thing: with panhard I don't have to calculate squat/antisuqat, isn't it?
Francesco
A Panhard bar has basically nothing to do with squat/antisquat. It is just another way of locating an axle under the truck. With links that are straight (or nearly so) the axle has the ability to walk side to side. A PH bar keeps the axle under the truck.
Also, when you have some sort of mechanical steering (not full hydraulic) a PH bar in the front can reduce the bumpsteer that is fairly prevalent in linked front suspensions.
And yes, you can have a stupid amount of articulation with a PH bar. I have 16" coilovers on the front of my rig. and use every inch of them...
You keep talking about antisquat like it is some unobtainable issue. It is not that bad. Figure out how you want your suspension to work, figure out where you can put your links, and then start using the 4 link calculator. Then fine tune your suspension from there.
It really is not that hard..
Also, when you have some sort of mechanical steering (not full hydraulic) a PH bar in the front can reduce the bumpsteer that is fairly prevalent in linked front suspensions.
And yes, you can have a stupid amount of articulation with a PH bar. I have 16" coilovers on the front of my rig. and use every inch of them...
You keep talking about antisquat like it is some unobtainable issue. It is not that bad. Figure out how you want your suspension to work, figure out where you can put your links, and then start using the 4 link calculator. Then fine tune your suspension from there.
It really is not that hard..
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- #26
yeah with all the research i did sometimes it is just what you can fit and were. i am not saying do no math but some of it just gets crazy. the key is take your time and think about what you are doing before you do it. i used adjustable style brackets on my uppers to adjust the anti-squat. that way i can optimise my setup. also i am going to run an anti-rock sway bar in tha back. with air shocks. the sway bar will help eliminate the gangsta leen around corners,(not that this is an on road vehicle), and increase traction. i am no rocket scientist and i am building a 4 link. i also moched up my 4 link with less expensive tube to make sure it would work. at $10.00 a foot you do not want to make any mistakes.
So, let's summarize:
Front axle: my intentions were to use a panhard bar, but basing on what you just said that sounds like a bad idea...:whoops:
Just one question: do I have enough space for all the bars?
Rear axle: probably an easier work, but still stands the question of wich system I should utilize? At this point I would say the four link, but here it is the matter: a friend of mine (an eingeneer) calculated the squat for me: his response is that to obtain a 80% I should low the car of about 6"! Of course I want my car to be as high as it is now, or maybe I can low it 1/1,5" but certanly not 6!
And now the last question: if I manage to set the link in the way the squat is a little better, wich is the percentage the car is still "driveable"? 100%?
Thanks everybody for your neverendig patience!!
Francesco
Front axle: my intentions were to use a panhard bar, but basing on what you just said that sounds like a bad idea...:whoops:
Just one question: do I have enough space for all the bars?
Rear axle: probably an easier work, but still stands the question of wich system I should utilize? At this point I would say the four link, but here it is the matter: a friend of mine (an eingeneer) calculated the squat for me: his response is that to obtain a 80% I should low the car of about 6"! Of course I want my car to be as high as it is now, or maybe I can low it 1/1,5" but certanly not 6!
And now the last question: if I manage to set the link in the way the squat is a little better, wich is the percentage the car is still "driveable"? 100%?
Thanks everybody for your neverendig patience!!
Francesco
Huh????
Why is a PH bar bad?? It is actually a good thing on front suspensions that have some sort of mechanical steering (your does)
looks to me like you have the room..
Get the 4 link calculatior and do the math yourself. You will be better for it.
http://mysite.verizon.net/triaged/fi...arLinkV3.0.zip
Why is a PH bar bad?? It is actually a good thing on front suspensions that have some sort of mechanical steering (your does)
looks to me like you have the room..
Get the 4 link calculatior and do the math yourself. You will be better for it.
http://mysite.verizon.net/triaged/fi...arLinkV3.0.zip
Ok, so is official: I'll do a panhard in the front!
Maybe like the one is shown in the first pictures of this topic, using uniballs for every joint.
The link doesn't work; I tried a 4link calculator, but with inches and technical english words for me is a little difficult...
But I know the geometric process to calculate it (gravity centre, istant centre etc.) so I think I can do even without the calc, maybe doing some empirical tries on the car (with ropes simulating the bars).
Francesco
Maybe like the one is shown in the first pictures of this topic, using uniballs for every joint.
The link doesn't work; I tried a 4link calculator, but with inches and technical english words for me is a little difficult...
But I know the geometric process to calculate it (gravity centre, istant centre etc.) so I think I can do even without the calc, maybe doing some empirical tries on the car (with ropes simulating the bars).
Francesco
- Thread starter
- #30
in the front the main reason people do a pan hard bar is that ,they do not have room to do a triangulated 4 link. so they do a 3 link setup with a panhard bar to stop the side to side action because of the missing link. if you have the space do a 4 link this is the best way to go but most peoples header gets in the way. i am going to do something simular to spaceghosts i talked to him at tellico about it. but a 3 link with panhard bar is a great setup many use this. a triangulated 4 link is the best way to go in the back. you should have plenty of room for that. and do not get too caught up in the anti squat some people like the comp guys run very little. go to www.pirate4x4.com thier is tons of stuff on different link suspensions. also www.proffittscruisers.com sells a premade setup. to each his own.
The reason most people do a panhard bar is to reduce the bumpsteer.
4 link is not the "best" way to go. it is simply an option that is available. If you try to run a 4 link and conventional steering when your suspension cycles, your steering wheel will move around, a lot...
Now which version of a 4 link is best for the rear??? and why??
4 link is not the "best" way to go. it is simply an option that is available. If you try to run a 4 link and conventional steering when your suspension cycles, your steering wheel will move around, a lot...
Now which version of a 4 link is best for the rear??? and why??
Ehm...a second question...?
Just jocking...I tought I can use the 4 link with the upper bars with a 45° angle and the lower bars parallel to the frame; that's the most common version I saw around.
The only reason I'm not so convinced about panhard is that I'm afraid I could lose the excursion and mobility of the axle, but I saw from some rigs (first of all SpaceGhost's Toy) that if the suspension is well tought that's not a problem at all.
So the definitive solution is a 4 link on the rear and a panhard on the front.
About bump steer (well...I guess bump steer means when the wheels vibrate while running and all the car shake and goes from side to side of the street...
) Mace you're right, I would reduce it as much as possible; I don't drive often on road (if police cacht me, they would send me in prison and burn my car! Here in Italy we have a lot of strict laws about modified cars! 
) but when I do I would have a driveable car...Francesco
Personally I like a 3 link with a panhard in the front over a wristed setup, less binding and wear on rod ends.
bump steer is actully fromt eh suspension cycling. As the axle gets closer or farther away from the frame the effective length of the drag link changes. So litterally, if you drive over a bump and hold the wheel straight, the car will change lanes. With a panhard bar, the axle actually travels in the same arc that the Drag link does (if they are the same length and angle which they shoud be as close as possible). So in the same situation, the truck tracks straight..
Death wobble is when the front suspension suddnley starts acting like a bucking bronco....
And I agree with bustantley, I really do not like the habits of wristed suspensions..
Death wobble is when the front suspension suddnley starts acting like a bucking bronco....
And I agree with bustantley, I really do not like the habits of wristed suspensions..
So, that's my Toy stretching his axles:
As I said I don't want a huuuge excursion, but do you think that with a rear 4 link and a front panhard I can mantain or have a little better behavior of suspensions?
Francesco
As I said I don't want a huuuge excursion, but do you think that with a rear 4 link and a front panhard I can mantain or have a little better behavior of suspensions?
Francesco
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- #36
i still have not decided on a wristed version or a straight up 3 link with pan. i am kinda leaning towards the 3 link that is what i was going to do at first it is a tried and true method. but after seeing mikes i had second thoughts good to see some input. i am a stickler thow on sticking to what works well and is simple. the simplier it is the easier to fix on trail. bending up the rear of truck this weekend will post up more picks after that.
I tried to calculate very quikly the squat of my car in case of lowering it for about 2,5":
I think the count is correct, it results a squat of 115 %...
Any comments? Is that squat bad? Did I do some mistakes calculating the value? Do you have any sugget to make the squat percentage better?
Francesco
I think the count is correct, it results a squat of 115 %...
Any comments? Is that squat bad? Did I do some mistakes calculating the value? Do you have any sugget to make the squat percentage better?
Francesco
looks about right.. for ~ 100% AS
But have you tried moving the axle/frame end links up or down to see what happens?
Also, you might want to consider instant center and roll center as well.
But have you tried moving the axle/frame end links up or down to see what happens?
Also, you might want to consider instant center and roll center as well.
Well...
The istant centre is that pont where the lines drawn by the two bars of the link (upper and lower) meet each other, isn't it?
The roll centre...ehm...I really don't know what it is!!
About moving the points of connection of the bars I noticed (but is almost obvious...) that the squat gets lower when I move up the axle's link and down the frame's links; in effect I think that's very important to study the better way and the best place where connect the bars.
A friend of mine told me that, basically, the upper bar has to be about 70 % of the lower; modifying my "project" in that way I think that squat could get also better.
Francesco
The istant centre is that pont where the lines drawn by the two bars of the link (upper and lower) meet each other, isn't it?
The roll centre...ehm...I really don't know what it is!!
About moving the points of connection of the bars I noticed (but is almost obvious...) that the squat gets lower when I move up the axle's link and down the frame's links; in effect I think that's very important to study the better way and the best place where connect the bars.
A friend of mine told me that, basically, the upper bar has to be about 70 % of the lower; modifying my "project" in that way I think that squat could get also better.
Francesco
