Pirate 4x4 banner

361 - 380 of 401 Posts

·
Registered
Joined
·
198 Posts
Well it seams this is used along with the link convergance piont to determain anti squat. Once you know were your center of gravity is along with your link center piont convergance you then draw a line from the rear contact patch of the tire to the link convergance piont. This line should cross the vertical line of the front tire and be between 50% and 80% ot the center of gravity line and the ground. This is a good place to start according to the mag write up. If you look at my bad drawings you will see alot of adjustment built into the rear uppers. This is to alow adjustment to find the sweet spot for anti squat. Hope this helps. If not let me know and I wll delete it:p
is there a reason for this. with my wheel base and height of vehicle and cog I cant get that line to be below the cog unless I make big huge mounts that hang down below the frame

the black line represents my frame the rest you guys can figure out, that was the most reasonable convergance point I could come up without the links mounting at the front of the cab.


the yellow line represents the line that is talked about in the quote


p.s. I dont think I will ever build a 4 link for this truck but just trying to learn for future projects. and dont flame me for the fender cuts. the truck was like that when I got it and have not had time to fix it yet. gonna build a deck for it.
 

·
Registered
Joined
·
198 Posts
this is an over the top view


can some one tell me if I am getting close for a general purpose set up

what I came up for with this set up is

94% AS
32* of triangulation on both upper and lower links.
6.8" of separation at axle
53" upper links
70" lower links
 

·
Registered
Joined
·
336 Posts
this is an over the top view


can some one tell me if I am getting close for a general purpose set up

what I came up for with this set up is

94% AS
32* of triangulation on both upper and lower links.
6.8" of separation at axle
53" upper links
70" lower links
Holy mother of....

53" uppers? and 70" lowers? what are you four linking? A school bus?

Edit: sorry, didn't read above...
 

·
Registered
Joined
·
1,255 Posts
Well, most of what I've learned on link suspensions has been in this thread, so anyone got any opinions on this?



Can't really triangulate the lowers any more. Big question is how much am I going to notice the 3° roll axis. (Offroad only, usually low speed, but hoping to speed things up a bit in the future)
 

·
Registered
Joined
·
1,255 Posts
Other than pinion angle change during travel, what would it matter? Pinion change is only 3°, & the "variable" AS numbers in travel look like they'd behave well. (Less AS as suspension droops out, slightly more under compression).
 

·
Registered
Joined
·
1,951 Posts
I am looking for the latest version of the 3 & 4 link calcs . Pm Ed Triag but no response yet. I have Excel to read them
 

·
Registered
Joined
·
505 Posts
Well, most of what I've learned on link suspensions has been in this thread, so anyone got any opinions on this?



Can't really triangulate the lowers any more. Big question is how much am I going to notice the 3° roll axis. (Offroad only, usually low speed, but hoping to speed things up a bit in the future)

Your frame side lowers are only 19.5" off the ground.... That is going to look goofy when you go to build it on your truck. I see huge drop brackets to make that work....

-G
 

·
Registered
Joined
·
1,255 Posts
It's a 100" wheelbase on 37's. Much more than 20" & it'll be sky high. Total bottom side of bracket is still slightly higher than my belly skid.
 

·
Registered
Joined
·
505 Posts
It's a 100" wheelbase on 37's. Much more than 20" & it'll be sky high. Total bottom side of bracket is still slightly higher than my belly skid.
That's cool then.... you are running a much lower ride height than I suspected. I'm at 26" belly on 38's so a 20" lower link bracket would be a disaster.....

-G
 

·
Registered
Joined
·
1,255 Posts
Still working around a stock frame, but narrowed on both ends with wide axles, so it's low & getting lower.

Main curiosity is the 3° roll axis. I know general rule of thumb is low as possible to slightly negative, but am I going to notice it bad?

Also now curious if I'm missing something running the uppers that short. I've got room to lengthen them, but would mean less total link triangulation, & exact same numbers elsewhere at static height, but numbers do worse things at both ends of travel. (For reference, according to calc., uppers are 65% of lowers. Actual link length is 68%)
 

·
Registered
Joined
·
9,898 Posts
Greg72:21732114 said:
Well, most of what I've learned on link suspensions has been in this thread, so anyone got any opinions on this?



Can't really triangulate the lowers any more. Big question is how much am I going to notice the 3° roll axis. (Offroad only, usually low speed, but hoping to speed things up a bit in the future)

Your frame side lowers are only 19.5" off the ground.... That is going to look goofy when you go to build it on your truck. I see huge drop brackets to make that work....

-G
Ever heard of an 18" belly height? Edit: was posting then got busy and didn't read your post.
Jethro that doesn't look to bad, 3degree roll axis will be slightly noticeable but not horrible as the axle will move a little left to right and forward backward under flex travel. I prefer a bit more antisquat between 50/70 seems to work real good. I have never ran uppers that short, so I won't say its bad but again I tend to run the uppers within 2" length of the lowers ussually 2" longer than the lowers and all the rigs I have setup climb and wheel very well. Link opinions are like assholes, every one has one some just smell worse than others.
 

·
Registered
Joined
·
1,255 Posts
Well, coming from leaves, it can't be any worse right? :homer:

Starting with a low AS# because I've got an almost 50/50 weight split, & am absolutely sick of the hopping. Planning a 3 point adjustable upper frame side mount. As of now it's drawn for one up & one down adjustment, but may change that to 2 down. (away from calc right now, but at 1.25" hole centers I think that was ~40, 60, & 80% AS options. Center hole base was ~25, 40, 60 & the 25 has an infinite IC)
 

·
Registered
Joined
·
101 Posts
Just summing up this thread as I just read the entire thing.

- read pages 1-9, 13-15 ( some ass hats in the middle ask bad questions and are answered with info that doesn't jive with the rest of the thread.)

- read CJ2ota's post on pg.14 he sums it up nicely

JETHROBODEAN
To fix your roll values have you considered increasing link separation at the frame or axles , like CJ2ota mentions on pg14 (separation meaning widen or narrow)
 

·
Registered
Joined
·
182 Posts
So, I have a question for you. I have read this entire thread, purchased a book on suspensions and played with the calculator. Its all really great stuff. But, my question is just how off do some of these numbers have to be to really notice a difference.

For example, my wifes' stock JK's numbers aren't all that great. From the builds I see people do, their numbers are much better. I have not off roaded her jeep but I hear in stock set up, they do quite well.


for example, the role axis on the JK is over 12%. That is pretty high by the standards in this thread. I would love to hear from folks who had to make corrections because the numbers where to high. How far off where your numbers and where did you have to set it before you were happy with it.
 

·
Premium Member
Joined
·
38 Posts
Thanks for this Cliff Notes version of this thread, appreciate it!
 
361 - 380 of 401 Posts
Top