I am in the process of designing a 4-link for the rear of my 91 shortbed toyota. The problem is it's not a trailer queen. I actually have to drive this thing to the trail. I am going to use johnny joints in the links, and am going with the double triangulated 4-link.

My question is: how would you design a 4-link so it is safe on the road? Do I need a panhard rod or is double triangulation enuf?

I would say that yes, double triangulation will be enough. The reaeson i belive that 4 links are usually rumored to be bad on the road, is that most people design them for the trail. The links are not what cause probs on the street, but it is the tendency for people to use really soft springs/coils to get more travel. This will result in lots of body rol and instability around corners. Just stay with stiffer springs, and you'll be fine.

Originally posted by elf_cruiser
people use really soft springs/coils to get more travel. This will result in lots of body rol and instability around corners. Just stay with stiffer springs, and you'll be fine.

Or you could just SLOOOOOW DOOOOWN..... That helps too. ;)Besides;l taking a corner at 25+mph in a trail rig is a stupid idea anyway.

Build it so it will work good on the trail and then put a detachable sway bar on it.:D:D

Desertoy I like your idea. Maby one of those torque rod antisway bars used in jeeps. I am using 1/4 eliptic springs.

the double triangulated link you are talking about, is that like the one on the sierra rock crawler site? green jeep with hilux axles?

i too am thinking about a 4 link and different spring setup...but needs to be streetable

Desertoy has a nice set up. Never thought to ask how does that thing drive?

Originally posted by elf_cruiser
I would say that yes, double triangulation will be enough. The reaeson i belive that 4 links are usually rumored to be bad on the road, is that most people design them for the trail. The links are not what cause probs on the street, but it is the tendency for people to use really soft springs/coils to get more travel. This will result in lots of body rol and instability around corners. Just stay with stiffer springs, and you'll be fine.

Exactly. I had this problem when I did mine. Just added another leaf to the pack and she drives like a dream, well at least better than stock.

also never neglect to run a good set of shocks... If you have the $$$$$$$$ go for the coilovers, they are very tunable... if you can't afford them, go for a set of rancho 9012s they are the standard and are nicely adjustable, stiffer is good on the road.

also a wide spring stance on the axle will allow you to go with softer springs and still have some stability. the closer together you mount your springs the more "Floppy" your rig will be.

A 4 link is a very streetable suspension, you just need to design it correctly. I would definitely put a removable sway bar in it. That will really control your body roll on the street yet allow you to run softer springs for flex on the trail. You also need to keep your rear roll axis sloping down towards the front. This will keep your vehicle from understeering in corners. I would also keep the virtual lengths of the arms really long (more then 100 inches) to control wheel and brake hop on the street. I hope this helps and good luck.

Originally posted by Suprdlux
I would also keep the virtual lengths of the arms really long (more then 100 inches) to control wheel and brake hop on the street. I hope this helps and good luck.

Virtual length ???? 100" ?????? explain please

By "virtual links", I think he is talking about where the upper and lower links intersect at the IC?

It is really hard to have your rear links sloping down towards the front of the vehicle for your roll axis. I always see them sloping up towards the front.

Originally posted by Eric
It is really hard to have your rear links sloping down towards the front of the vehicle for your roll axis. I always see them sloping up towards the front.

Yep, between packaging and making the suspension move with the rnage you want it is hard to do.

Setting the RC on the front lower than the rear though will make the entire vehicle roll axis slope in a good way to tune out the rear suspension's roll oversteer (edit: somewhat).

r@m

Originally posted by Root Moose


Yep, between packaging and making the suspension move with the rnage you want it is hard to do.

Setting the RC on the front lower than the rear though will make the entire vehicle roll axis slope in a good way to tune out the rear suspension's roll oversteer (edit: somewhat).

r@m

How do I set the RC in the front when I'm keeping the stock leaf spring setup. (not stock springs, stock design)??

The RC is the line between the IC points of the top and bottom links right?? So wouldn't it be eisier to get a RC the slopes down tword the front if I have the top links sloping up tword the rear??