3 Link numbers goal

:looney: This is how I feel after almost a year of reading putting it down and picking it up again! No one that I can find list or even talk about what % or numbers goal to shoot for! They all say make your links longer, spread them out on the axle farther, lower your roll center, raise your roll center, lower your anti dive, raise it:looney:!!!! I did not go through all this brain fatiguing when I linked my van and, I know it's just for towing and trails but, it works great! No bump steer ect...!!!
So I'll get to the point. I have two sets of numbers and any range in between the two is ok as well, so I will post them for opinions from the veterans and you know who you are!
1st the vehicle: XJ 36x15.50 x15 MTZ's, dblr with Dana 300, 4.56 locked 9''s front and rear, ORI's front leaf rear.
2nd the driving style: 70% crawling, 15% go fast, 15% street, towed to big events but prefer to drive if possible!
3rd Numbers:
1st 2nd
A/S --- 96.13 --- 61.56
Roll Axis --- 2.11 --- 0.79
R/C --- 27.22 --- 27.08
I/C X --- 71.12 --- 128.66
I/C Z --- 28.0 --- 32.44

So without having a goal to shoot for I do not know which is better!
My roll center just doesn't seem to change much so there's my confusion. My COG may be high at 43 but I can only estimate that all other numbers are dead on! If anyone has input advice I will digest and implement! Thanks If you need the other #'s just let me know. I did not want to bore most with additional info!

Here's what I learned when I was researching 3 links. Lower links angles the same. Around 5" frame separation, 8" or so of axle separation, upper link slightly longer and as flat as you can get it at ride height. That's it. Just build. You don't see many people posting about that stuff because it's not necessary

Yeah I guess! But then there is a lot of people talking about it but not listing a norm for crawling, street or go fast. I know that there has to be a perfect medium for the set up! !!!1 Like I said; My van goes straight down the road even without a front sway bar! I just read too much I guess! However I would like to know two things, if the upper and lower link intersecting lines, which I believe is my roll axis, would be best before the rear axle or after?


Something like this would help! You want your A/S 40 to 50%
Roll Axis less than _%
Roll Center near _''
I/C X axis near _"
I/C Y axis near _"
I get all the lower arms as long as possible stuff! Then as you said, and I agree, the upper parallel but slightly longer which limits the uca link because of t-case if you have long lowers! There has to be a perfect numbers range out there that works for both styles of driving! The Hammers guys are doing it slow and fast so????
I don't know if Cal, Goat, Avery or any other race guys would like to chime in but I know there are guys in here that have a clue!

I am no expert nor built a 3 link but have read the "Pirate TOTM: 3 Link" handful of times and have found that building a 3 link at full bump allows you to see any possible clearance issues.

If you want to go fast in the sand and over bumps then build the upper link a bit longer than the lowers to maintain good pinion angle throughout axle droop and compression.

If correct caster throughout droop and compression is more important then build the upper slightly shorter than the lowers.

There was also a bit of discussion about axle hop/unloading in the same pirate thread and the idea is that spring rate and shock choice has more authority than link geometry evidently.

Also bump steer and driving down the road strait are not related to suspension link geometry but caster and trac bar/drag link angles.

I believe you will find enough information in this thread to help guide you to your answer.

Post up some results after you build it of course!

Yes on the caster and pan hard, that is why the van and my radius arm XJ do so well! I was aware of all that and read the Pirate site as well! I did my van well before I read anything just by my past experience in converting 2wd to 4wd trucks. I've done close to a dozen or so, both spring and coils. This is where I become confused with all the numbers. I will measure my wifes' stock XJ, input those numbers. Then just for comparison, maybe my van just for additional numbers. I can't really get any comparable numbers goal so I will make my own list! I guess I could have done the XJ measurements before I hacked off the radius mounts but too late for that!
I've gone ahead and ordered the ORI's. I was going to go 18"s but I did not want to have to cut into the hood since it was going to be a close fit for them under my cowl spaced hood! If I do need the extra 2"s of droop I can make that up by going with taller rubber!

One of the posters stated how he just built his on a neighborhood driveway blah blah blah! Been there, did all that. I am just trying to comprehend the numbers for my own interest to understand the mathematics of it. It would make it easier to understand how to correct bad behavior of the suspension! Any way I am moving on!

I did not mean blah blah blah sounds rude! So I apologize for that! What I meant was all the comments but no numbers!

Ok re-read page 5 so I'm good. Thanks I feel better plus the dog ate my calculator sheets, I guess he wanted them more than I!

Moderators I authorize removal of post!

I feel your pain, when I built my 3 link I spent hours and hours reading but most of the time I was just confused and the calculator doesn't help. I did however read a post somewhere that said this:

1. 6 inches of separation at the frame.
2. 8 inches at the axle.
3. Upper should be within an inch of the lower and as flat as possible.

So I closed the calculator and took the plunge. When I started doing the math I couldn't get 6 inches or a completely flat upper on the drivers side without going into the floor. So I moved my upper to the passengers side and cut the floorboard. Been running it about a year now and it climbs like it's possessed....I one shot both this big ledges below with no unloading, no wheel hop. Of the 4 rigs that attempted the first ledge I was the only half-ton rig (all the rest were big one-ton crawlers) and the only one who didn't take the hook. Hope this helps.

first suggestion would be to close the calculator. truth is... unless you are building a dedicated race rig and have a very well calibrated butt dyno (in other words... race for a living and are tuned in to small handling changes) you are not going to notice the difference between 102% and 98% AS/AD.

the basic rules of building a cherokee 3 link work because the cherokee lends itself well to good geometry. if you are a person that likes to see numbers, i suggest doing some measuring and seeing where the links fit best. then going back and putting them into the calculator. this is what i did, and ended up with beyond acceptable numbers. there will be a difference depending on if you decide to go through the floor or not.

Thanks
I decided on my last post before this to do what you suggested! All that wasted timeaperwork, I should of just done it like I did my van, in a weekend!