"Gonna do it right...maybe!!??" Fuller's new XJ build!!!

Dont let @shawn see your links as I dont see plug welds and he will loose his shit.
 
BRUISER said:
Dont let @shawn see your links as I dont see plug welds and he will loose his shit.
Click to expand...

I can plug weld them with Crocs on. Super easy, man. Hell, he can probably plug weld them now. Just need to be careful not to break through into the threads. ;)
 
dang been off track lately, family visiting and other work to do. made little progress though
been playing with this link calculator and after several hours on it, I'm no further along than when I started WTH lol
I'm usually pretty good at math but this calculator puts wording in such weird terms..I've done researched so much already but most of what I'm reading is just more jiberish ...
so I don't know but I've figured this out:
my lower links are very good according to pretty much all lower link related topics/discussions and several different data sheets I've looked at I.E: they are very level to the ground, good length ...
34.75" center to center at frame end seperation lower link
41.6" center to center at axle end seperation lower link
distance from ground to frame side lower link is 22"
distance from ground to axle end link is 18.5" so this is pretty good and level from what I've been reading up
lower links measure 38.5 center to center
upper link will come off lower link on passenger side and measure roughly 27.9 center to center (chose this rather than driver side to not interfere with track bar and draglink that will be in that area and passenger side is free and clear)
my caster is back to 0 rather than -2 also and pinion is perfect where it sits currently so I'm happy with it so far.
this is what I've got so far but I'm frustrated with trying to use the computer to give me a upper link measurement so I just chose the 27.9" as it appears to be about what I've read is a good percentage of the lower that people recommend on 3 link radius setup...
thoughts/input is welcome but can't promise anything lol, I'm overloaded
 
This is my links and proposed upper link mount
IMG_20180302_230816666.jpg
IMG_20180302_230614227.jpg
 
Caster should be positive, which means the knuckle is leaned back at the top. Try for at least 3*. Caster is also relative to the ground, so the vehicle should be at ride height before you actually set it for good.
 
NC-V said:
While I agree with your point of teaching him right and wrong. I also feel he will be perfectly fine in this situation and may actually benefit from the increased spring rate. His cage probably weighs 1000lbs, he could use some extra spring rate...

That said, I hope he didn't just cut out 2" of coil expecting it to lower the ride height 2"
Click to expand...
can you emphaize on this a little about spring rate. I did my research on cutting a 6.5" spring down to the measurement for 3.75-4.25" of lift but didn't really comprehend the spring rate change...sorry there is sooo much info going on right now I'm trying to focus on so much but forcing myself to not get caught up on just one thing and keep pressing forward slowly of course not rushing. thanks
 
Croatan_Kid said:
Caster should be positive, which means the knuckle is leaned back at the top. Try for at least 3*. Caster is also relative to the ground, so the vehicle should be at ride height before you actually set it for good.
Click to expand...
i agree but it's been stated already for just a crawler, I can get by with 0 and let the pinion be the more focal point rather than caster. At least its not tilted forward couple degrees anymore and once I make the driveshaft for it soon, I will be able to at minimum probably go a hair back as I cycle suspension when upper link is done and driveshaft is installed. right now looks like I should clear the driveshaft at full droop no problem without binding the axle end joint and that's my focus.
 
3* likely won't move the pinion very much, so you'll probably be able to do both.
 
marty79 said:
can you emphaize on this a little about spring rate. I did my research on cutting a 6.5" spring down to the measurement for 3.75-4.25" of lift but didn't really comprehend the spring rate change...sorry there is sooo much info going on right now I'm trying to focus on so much but forcing myself to not get caught up on just one thing and keep pressing forward slowly of course not rushing. thanks
Click to expand...
Spring rate isn't just a "hard and fast" number for any given coil. It is dependent on wire diameter, outside diameter, and active coils. If you remove some of the coils, the obvious effect is that you'll reduce the length of the spring, thus reducing the height of the vehicle. The inherent issue (good/bad/indifferent - you decide) is that there is an increase in spring rate.

Calculating a spring rate goes as follows: [(elastic modulus of spring material)*(wire diameter)^4]/[8*(number of active coils)*(outside diameter of spring)^3]

Since you reduced the number of active coils, the denominator in the equation that calculates the spring rate got smaller, thus increasing the effective spring rate.
 
Scooter402 said:
thus increasing the effective spring rate.
Click to expand...
so for the extra added weight of rig as someone stated, this can be a good thing?
spring rate is how stiff/loose the spring moves up and down and how fast it does that?
 
Aside: another net effect of the increased spring rate (and what @NC-V) was eluding to was that if you cut x" off of the spring, the increased rate will not result with the same x" of drop in suspension height.
 
marty79 said:
so for the extra added weight of rig as someone stated, this can be a good thing?
spring rate is how stiff/loose the spring moves up and down and how fast it does that?
Click to expand...
Spring rate is how stiff the spring is, or how resistant it is to change in height per force applied to the spring. F=-kx, where F is force applied, k is spring rate, and x is distance changed with force applied. With the direct relationship, the increased spring rate results in a higher force needed (added weight) to move the spring the same distance. So yes, the increased spring rate can be a good thing with the added weight.

How fast it does so is controlled by your shocks. An increased spring rate will not control how fast it moves, only it's resistance to the change.
 
Scooter402 said:
Spring rate is how stiff the spring is, or how resistant it is to change in height per force applied to the spring. F=-kx, where F is force applied, k is spring rate, and x is distance changed with force applied. With the direct relationship, the increased spring rate results in a higher force needed (added weight) to move the spring the same distance. So yes, the increased spring rate can be a good thing with the added weight.

How fast it does so is controlled by your shocks. An increased spring rate will not control how fast it moves, only it's resistance to the change.
Click to expand...
Well it's definitely changed the height which it should have according to how I measured. It's about 3" shorter lift already. Started out at almost 7" so big change now and it's almost got the whole weight on it without the body being off the Jack's so I'm happy with the outcome
 
that steel paper towel tube welded in vertically inside the spring - whats that all about?, it will catch the inside of the springs with any amount of L/R flex and make hella noise. go ahead and take it out now. were you intending that to be integrated into a bump stop?



do you understand that the spring will twist as it loads/unloads? thats why a cut is not necessarily a good idea. a properly made coil bucket is adjusted for the angle of a not flat coil end. if you want to keep a coil like that, make a ramped bottom to distribute the force. solidly pin the bottom so it wont spin and eventually dig into / though the mount. make it spin in the upper only. I think the lower buckets were originally like that. use limit, straps to control droop, not your shock length. Ive found that a center limit strap works better than one at each corner, as it controls center droop at high speed a bit better. also keeps the tires from grabbing and tearing it out. a coil sprung front will want to unload hard on a hillclimb too, so you dont want it dropping away like crazy. but a center strap at the right length will still allow for crazy flex
 
Chuckman said:
use limit, straps to control droop, not your shock length. Ive found that a center limit strap works better than one at each corner, as it controls center droop at high speed a bit better. also keeps the tires from grabbing and tearing it out. a coil sprung front will want to unload hard on a hillclimb too, so you dont want it dropping away like crazy. but a center strap at the right length will still allow for crazy flex
Click to expand...

If he doesn't use one at each corner and only one in the middle the way you suggest then when only one side is compressed and the other extends the shock will be what limits the droop on that end, not the middle limit strap. That kind of negates what you said about not using the shock as a limit strap. If you mount it correctly your tires shouldn't get into your limit strap.
 
marty79 said:
dang been off track lately, family visiting and other work to do. made little progress though
been playing with this link calculator and after several hours on it, I'm no further along than when I started WTH lol
I'm usually pretty good at math but this calculator puts wording in such weird terms..I've done researched so much already but most of what I'm reading is just more jiberish ...
so I don't know but I've figured this out:
my lower links are very good according to pretty much all lower link related topics/discussions and several different data sheets I've looked at I.E: they are very level to the ground, good length ...
34.75" center to center at frame end seperation lower link
41.6" center to center at axle end seperation lower link
distance from ground to frame side lower link is 22"
distance from ground to axle end link is 18.5" so this is pretty good and level from what I've been reading up
lower links measure 38.5 center to center
upper link will come off lower link on passenger side and measure roughly 27.9 center to center (chose this rather than driver side to not interfere with track bar and draglink that will be in that area and passenger side is free and clear)
my caster is back to 0 rather than -2 also and pinion is perfect where it sits currently so I'm happy with it so far.
this is what I've got so far but I'm frustrated with trying to use the computer to give me a upper link measurement so I just chose the 27.9" as it appears to be about what I've read is a good percentage of the lower that people recommend on 3 link radius setup...
thoughts/input is welcome but can't promise anything lol, I'm overloaded
Click to expand...
To calculate the radius arm correctly in a 3link calculator, you need to place the frame side upper mounting point at the same location as the frame side lower moiunting point.

While upper arm length and placement can effect strength of the arms, it doesn't effect geometry, as the upper and lower will move together relative to the frame and axle.
 
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