It's time for some 4link #s

Yay!Gurrr

Yay!Gurrr

Better Faster Stronger
Moderator
Joined
Mar 17, 2005
Location
N. N. Raleigh, NC
First: I know its just numbers on paper, real world is where it's at etc.. (4link 4-link)

I've followed all the advice I've been collecting over the years as far as suspension designs and comments/input from here and pbb..

The summary of things to try to do:
- try to make your links parallel when viewed from the side
- make them as long as you reasonably can
- make them as flat as you reasonably can
- make the roll axis as high as you reasonably can
- vertical separation should be 6" or more. More especially for more horsepower and/or bigger tires.
- make the triangulated portion 40 degrees or more for decent lateral control.

With that. Here's what I've come up with. After hanging the motor in place to check fitment I came up with some real life measurements that I can hit with the link mounts
Note: Looking to do this on both ends with same setup..
I have lots of adjustment on the frame side upper.
Can hit 0%-150% AS

What say ye!

4linkv2.1.jpg
 
looks like you'll be able to dial it in perfectly to your liking with that range of adjustment.
Did you play around with the travel AS any?
 
it looks good. i would deff look at it throughout the travel, as it will really tell you more than at ride height...

also, i may be wrong, but i would think you want a little more AS... iirc, most stock vehicles are around 85%
 
yager said:
The summary of things to try to do:
- try to make your links parallel when viewed from the side
- make them as long as you reasonably can
- make them as flat as you reasonably can
- make the roll axis as high as you reasonably can
- vertical separation should be 6" or more. More especially for more horsepower and/or bigger tires.
- make the triangulated portion 40 degrees or more for decent lateral control.
Click to expand...

And you just saved a lot of people countless hours of reading :)

Can you explain what the roll axis is? I would assume to get the highest roll axis you would mount the upper links high as possible and the lowers as high as possible but not to be within 6" of vertical seperation. Correct?
 
I'm not an expert I barley understand most of it. If your doing any homework I suggest spending at least 2-3 weeks reading ALL of the threads, even the long 20page long ones that are full of BS and arguing, there are lots of good points that get made...

I found most of that information in 1-2 good 'summary' threads from some of the more better competent folks on PBB as well as the advise that has been offered here by the guys building stuff here..

Roll Axis = I have more of the summary docs at work, ill post them in a new thread. I've found most of it to be very helpful. Basically read them 100x until you it finally makes sense.

Other stuff = Get the speadsheet and play with the numbers. It helps to do this while reading the info. Again its just numbers and many people aren't starting from scratch or have the ability to make needed changes and more/less use what they have... AND guess what.... They usually work ok for most people..

That said..... Back to me :)
I changed the upper frame link to:
22" AS = 85% static... 6" Bump = 109% AS / -6" Droop = 88%
22.5" AS = 72% Static 6" Bump = 91% AS / -6" Droop = 79%

As far as static #s I just wanted to make sure I could hit the range I wanted on paper so I had some fudge when it actually hits the frame.
 
yager said:
I'm not an expert I barley understand most of it. If your doing any homework I suggest spending at least 2-3 weeks reading ALL of the threads, even the long 20page long ones that are full of BS and arguing, there are lots of good points that get made...

I found most of that information in 1-2 good 'summary' threads from some of the more better competent folks on PBB as well as the advise that has been offered here by the guys building stuff here..

Roll Axis = I have more of the summary docs at work, ill post them in a new thread. I've found most of it to be very helpful. Basically read them 100x until you it finally makes sense.

Other stuff = Get the speadsheet and play with the numbers. It helps to do this while reading the info. Again its just numbers and many people aren't starting from scratch or have the ability to make needed changes and more/less use what they have... AND guess what.... They usually work ok for most people..

That said..... Back to me :)
I changed the upper frame link to:
22" AS = 85% static... 6" Bump = 109% AS / -6" Droop = 88%
22.5" AS = 72% Static 6" Bump = 91% AS / -6" Droop = 79%

As far as static #s I just wanted to make sure I could hit the range I wanted on paper so I had some fudge when it actually hits the frame.
Click to expand...

That's a pretty consistent AS from bump to droop. Start welding!
 
Glad you posted this. I am getting ready to start tacking my bracket on this week and looks like my set up will be very similar to yours. Where did you get that calculator?
 
Ok I stated a new thread for the 4link suspension information...
http://nc4x4.com/forums/showthread.php?p=666888

I was pretty happy with the numbers on paper, I just need to see if I can hold them putting it together.

4 link Calc.
Pbb thread: http://www.pirate4x4.com/forum/showthread.php?t=204893
Good read. Note: Wheel travel mod was provided by Vetteboy79
FileDownload: Triaged on Pbb http://mysite.verizon.net/triaged/files/4BarLinkV3.1d.zip

Note: I modified the part on the right side based on my pet peeves to show link length, vertical separation and combined link angles. Its a few simple formulars I can cut paste that tomarrow (thats on my work machine).

Blah Blah Blah...
 
yager said:
That said..... Back to me :)
I changed the upper frame link to:
22" AS = 85% static... 6" Bump = 109% AS / -6" Droop = 88%
22.5" AS = 72% Static 6" Bump = 91% AS / -6" Droop = 79%

As far as static #s I just wanted to make sure I could hit the range I wanted on paper so I had some fudge when it actually hits the frame.
Click to expand...


both of these numbers look like they would work well...
 
Back
Top