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I guess driving a full time constant 4wd (centre diff) vehicle must mask a lot of what the pirate community has been preaching for over a decade. Stock my Land Rover would have had +4 - +6 degrees rear axle roll axis, a simple 2.5 spring lift increased that a fair amount. I never had it swap ends, never killed the nuns or spontaniously combusted. Now im not saying those numbers ideal, But IMO I would like to have no less than 0, preferably +2 - +3.

Given the restraints of my build im at +5 with a 39.4" link. So i think it will be fine.

Remember these vehicles want to understeer by the sheer nature of physics. And Vehicle roll axis (front to rear RC height relation) plays an important roll as well.

Id still triangulate your lowers a little if packaging allows and get your AS a bit lower still.

Where does a all round vehicle need higher AS that it wont benefit from lower AS...
 

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Discussion Starter #22
Another option after sitting with the truck frame for an hour or so.



This will be my last go. Next I will start mocking up and tack welding stuff.

Figured this is as far as I can get with the calculator alone.

Ended up in a lot different setup with your help.

Will post updates from the build as I go. Just working on a site so I don't have to constantly send the same thing to multiple people.
Thanks again

Scott
 

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I guess driving a full time constant 4wd (centre diff) vehicle must mask a lot of what the pirate community has been preaching for over a decade. Stock my Land Rover would have had +4 - +6 degrees rear axle roll axis, a simple 2.5 spring lift increased that a fair amount. I never had it swap ends, never killed the nuns or spontaniously combusted. Now im not saying those numbers ideal, But IMO I would like to have no less than 0, preferably +2 - +3.

Given the restraints of my build im at +5 with a 39.4" link. So i think it will be fine.

Remember these vehicles want to understeer by the sheer nature of physics. And Vehicle roll axis (front to rear RC height relation) plays an important roll as well.

Id still triangulate your lowers a little if packaging allows and get your AS a bit lower still.

Where does a all round vehicle need higher AS that it wont benefit from lower AS...


Having a center diff will change what your actual AS numbers are compared to what the calculator spits out. If it adjusts the torque split between F&R, you're never really going to know what your AS is. The calculator assumes 100% going to that end, unless it's the new version that does both the front and rear and allows you to set the front drive bias.


New F&R version, notice the front bias box. Notice it's set to 0.50, that would be a "standard" gear to gear TC in 4wd (50/50 split). Even torque split between front and rear. A center diff in the TC would change that.


Capture.jpg


This is a capture of what my rear AS is with that 50/50 split.


Capture1.JPG



If I input 0.00 to the front bias box (when in 2wd) those AS numbers double.
 

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Having a center diff will change what your actual AS numbers are compared to what the calculator spits out. If it adjusts the torque split between F&R, you're never really going to know what your AS is. The calculator assumes 100% going to that end, unless it's the new version that does both the front and rear and allows you to set the front drive bias.


New F&R version, notice the front bias box. Notice it's set to 0.50, that would be a "standard" gear to gear TC in 4wd (50/50 split). Even torque split between front and rear. A center diff in the TC would change that.


View attachment 2977512


This is a capture of what my rear AS is with that 50/50 split.


View attachment 2977514



If I input 0.00 to the front bias box (when in 2wd) those AS numbers double.
Yep, but I was more hinting at the usual "must have understeer axle geometry"...

A centre diff on road will pretty much just give 50/50 in dry conditions. It gets locked up for off road work, so becomes the same as a standard T/Case. My current build has a Auto Torque Bias diff (that is also fully lockable for off road) so will be interesting to compare its characteristics.

again I dont see the harm in having a touch of oversteer given understeer by nature.
 

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Ok try number 4? 5?... gah lost count.




This seems to check all the boxes. .. Although not sure about dipping the upper links like I am.


Thanks

Scott
I like this one the most from what you have posted. Id still lower AS a bit. And have you checked the pinion change through bump/droop?
 

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Ok try number 4? 5?... gah lost count.




This seems to check all the boxes. .. Although not sure about dipping the upper links like I am.


Thanks

Scott
This version looks the best overall, I'd go for lower AS still personally, but you won't be disappointed with this setup either way.
 

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Discussion Starter #31
welp updating the calculator let me know I was entering my data wrong.

:mad3::mad3::mad3::mad3::mad3:

I was entering the full horizontal separation of the links vs 1/2. Once I saw the wheel base drawn from the top view it was really obvious.

good lord maybe I should rethink my choices in life... lol.

Scott
 

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welp updating the calculator let me know I was entering my data wrong.

:mad3::mad3::mad3::mad3::mad3:

I was entering the full horizontal separation of the links vs 1/2. Once I saw the wheel base drawn from the top view it was really obvious.

good lord maybe I should rethink my choices in life... lol.

Scott

Been there done that. Lol

At least you caught it before you started burning metal.


Sent from my iPhone using Tapatalk
 

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welp updating the calculator let me know I was entering my data wrong.

:mad3::mad3::mad3::mad3::mad3:

I was entering the full horizontal separation of the links vs 1/2. Once I saw the wheel base drawn from the top view it was really obvious.

good lord maybe I should rethink my choices in life... lol.

Scott

Don't worry about it. You'd have known something was up when you held a link mount up to a wheel stud.:flipoff2:
 

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Discussion Starter #34
problem I am having now is my frame is narrow so getting enough triangulation in my top links (40 degrees) is proving to be interesting.

back to the drawing board.

Scott
 

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GIJEEPN
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Most of the time you only need >40 degrees in one of the sets of arms. So the angle of each lower link can be about 22 degrees and still get the benefits of triangulation

I’ve even read (can’t remember where) that you actually need the angles of all the links on one axle to equal >40 degrees.

If this is true, then having both uppers at 11 degrees and both lowers at 11 degrees will work just as well.

YMMV
joel


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Discussion Starter #36
would love to know if that is true.

with much effort I can get 18 degrees on each of the top links and 17 degrees on each of the bottom links.

Scott
 

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GIJEEPN
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Ok this is what I have now.
Thanks again for all the help and patience with me.
Scott
You're welcome for the help. lol.

from what I gather from your numbers:
You uppers will be spaced 20.50" apart.

--> Is this because of the limit of your frame?

You have the lowers directly under the uppers.

-->Is this because you are purchasing mounts that are built that way (e.g. the Artec 4 link mounts).

Your putting your LCA Axle mounts 37" apart.

-->Is this because there isn't enough room to make then wider on the axle?

If you could widen the LCA Axle mounts by 1.25" per side, you would have the 40* of separation

You can build a cross member across the frame where you want the LCA frame mounts to be and attach them to it closer to the center of the vehicle.

You can shorten the arms. Shortening all the arms by 3.5" will get you in the triangulation window as well.

Also, please note that if you triangulate either or both sets of bars you WILL NOT use a panhard bar.
 
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