Q&A Link Tech

Hi Guys and Gals. Since 3linking and 4linking Tacomas and 4Runners is so popular these days, I'd thought Id try and answer questions regarding the subject. I'd like to open the door to discussion on the matter. If you're interested or just want general info please feel free to ask what ever question you like and I'll do my best to answer it.

 

Sub’d!

Not planning on SAS anytime soon, but someday...

 

I'm in for info!

 

Subd

 

Its a Q&A thread. Ask a way.

 

I am building an all around 2001 DC that I am putting in an LM7/4L60e/NWF black box/241D, after that I'm 3 linking an FJ80 front with 12" saws/FJ80 FF rear with chevy 63s on 37s. I'm looking for 5"up/7"dn and 22"-24" frame height. I am going for a streetable trail truck and I am willing to sacrifice some articulation/travel for street and highway manners.
All that said, the widest I can get on the front axle is 44" outside bracket to outside bracket. The link calculator can be intimidating and not a lot of off road guys care about street manners. I would like to be able to drive cross country hunting/fishing/wheeling if possible.
What would be a good place to start for numbers?
How much more/less should I try to triangulate everything?
I was told to try to get the links as long and flat as possible, that good advice for what I'm after?

 

On that axle you're most likely going to be around 40" max on lower link width from each other when measured eye to eye. Which is all you really need. Triangulation of the lowers no matter if its a 3link or 4link is helps with roll axis numbers. Which really just means the front to back swing of the axle has been minimized so that it doesnt steer the car in a turn or on a road that is prone to body lean. But something to remember or note about triangulated lowers is that there force or resistance is in the same direction they are pointed. So the more triangulation you have the less resistance to body lean you have.

As for longer link arms. That kind of depends on what you think long is. I typically use a 39-42 inch arm. Any longer and the arms get weaker due to length and their location on the chassis becomes less effective to controlling the vehicle. As in the closer they are to the center of the vehicle the less effect they have on the vehicle.

 

I was shooting for 40ish" lower links and a 36ish" upper link.

 

Hey I use similar numbers my self on link lengths. But why focus on length so much when its 1-10 of the different things to focus on.

 

I am sure that I will have some general questions soon. Almost done buying all the parts I need. What kind of general advice would you give a first time builder?

 

That was just what I have been advised to do by a guy I trust. 1/10s add up fast and that's one less thing for me to fuck up lol. I would like to get some numbers from someone who has a comparable set up and achieved the same goal as me.

 

A lower link that is 10 degrees from the ground is far to steeply angled. Shot for 5 degrees or less.

 

Less than 1 degree oversteer (roll axis) is what i'd shoot for.
No less than 70% Anti Dive

 

That's really good to know! Any other little bits like that?

Anti dive I can keep about 80%. I'll have to go back for the roll axis and see what I can do since I put the v8 in.

 

Do you have a build on here, Ty? Seems like you’re going for a similar application as what I'd be doing in a few years once I get some good use out of my mid-travel setup.

 

I started a page when I got the truck, I was going to update it but the whole picture thing sucks and I hate dealing with it. Plans have seriously changed though, I found cracks that were cutting off the LCA mount on both sides of the sub frame right behind the rack. So basically the camber was growing at an alarming rate. I was going to fix it but I would have to weld a new sub frame in. That's a lot of work for IFS when a strait axle is way better. Plus it broke without any real upgrades, so I would hate to see what happens when I really start to play with it lol. Basically, that became the excuse to go full retard on the truck and now I have a chevy v8 and a shit ton of very expensive parts and more to buy. Seriously though, a cocaine addiction would be cheaper than these things.

On a side note, I been watchin your build and every time I click on it I start singin run to the hills. I just want to thank you for that lol

 

Tip #2. Coilovers don't unload, bad suspension geometry does. Which is why so many people like to use ORI struts.

 

So basically a coilover can't go over 90*, cause that causes them to unload? Also I read that ORIs ride height can depend on temp.

 

Im not following on the coilovers.

Yes on the ORI's. They will rise upwards of 4"s during a day.

 

So if a coilover from left 89* to upright 90* then right 89* that's what causes them to unload?