Questions about an SOA for a broke college student.

[Fieldtester96]

Caster is key. If you can’t keep 2 degrees in a lifted truck, it will handle like crap.

Regarding cut and turn, you need to do it with a spring over. It gives many advantages. First, you can set caster perfectly. Second, you can set pinion angle perfectly. And as an adjunct to #2, you get much better clearance under the pinion which protects it from rocks and saves your lower yoke. It is true that FJ62 has 1 degree more pinion angle, but that is not enough to obviate the need for a cut and turn.

Here is some friendly advice. Spend 6 months learning about steering geometry and driveshaft geometry and you will be far better prepared in the future

But in the end, I recommend a spring over only when you have another car to actually drive. Spring over Land Cruisers are not acceptable daily drivers. They are too big and too unsafe for everyday use. The risk is acceptable for weekend or trail use, but otherwise not.

I probably will do that in the end, and when i was driving mine with an SOA i didnt really feel like it was unsafe. Though i agree that its just to big, though it only got taller it was just more than i was expecting. I will definitely only do that when i have a second vehicle mainly because its just obnoxiously big. I will definitely do more research into steering now that i have experienced what happens when steering is bad.

 

[cruisermatt]

Any improperly designed and built suspension is unsafe.

My SOA I designed IS properly built and and safe, I daily drive it.
I spent about 5 years researching options, learning vehicle dynamics, fabrication, component choice, before I removed a single original bolt.

 

[lcwizard]

don't know how I missed this one....
About relay rod angles and bending them...
The issue with a steep angle is that all rod ends have a rotation limit. In the case of a 40, 80 or 60 series it's around 25~30 degrees.
At the bottom of the relay rod, the rod end post inserts parallel to the ground so as the angle steepens the drag link just rotates around
the pin never getting stressed. At the pitman, the post is inserted perpendicular to the ground. When the drag link droops it
can only flex until travel in the joint hits the limit. At that point, more travel requires the relay rod or pitman arm to flex, or the rod end to break.
I've seen cruisers with too long of a front shock and tall lifts that when placed on a lift and let fully droop, the rod end at the pitman
was supporting the whole weight of the axle at the bottom of the travel.
If you find the need to accommodate a serious drag link angle the ES2027 GM one ton ends will bend about 45 degrees . The post
is a bit larger so the the pitman will need reaming. the threads are 7/8 vs 21mm for the Cruiser so the tubing can be of the same
outer dimension.
Bending a relay to clear parts will only do that...clear a part. It won't address steering issues that come with steep angles.
Bump steer happens when the front end compresses and the the relay rod, traveling in an arc, changes the distance between point "a"
and "b" , "a" being the pitman and "b" the knuckle. The steeper the angle, the more the bump steer. Very soft suspension, like in a SOA
will dive more than stiff suspension. Shocks can help but a better relay angle is the safest answer. Bending the relay doesn't change
this. Whether the rod is straight, "S" shaped, a complete circle or a "W" the relationship between point "a" and "b" is all that matters.
With a steep angle, you slam on the brakes, the front dives and one of two things must happen..the steering wheel either moves left
or the wheels turn right ( opposite in Australia )

 

[Fieldtester96]

don't know how I missed this one....
About relay rod angles and bending them...
The issue with a steep angle is that all rod ends have a rotation limit. In the case of a 40, 80 or 60 series it's around 25~30 degrees.
At the bottom of the relay rod, the rod end post inserts parallel to the ground so as the angle steepens the drag link just rotates around
the pin never getting stressed. At the pitman, the post is inserted perpendicular to the ground. When the drag link droops it
can only flex until travel in the joint hits the limit. At that point, more travel requires the relay rod or pitman arm to flex, or the rod end to break.
I've seen cruisers with too long of a front shock and tall lifts that when placed on a lift and let fully droop, the rod end at the pitman
was supporting the whole weight of the axle at the bottom of the travel.
If you find the need to accommodate a serious drag link angle the ES2027 GM one ton ends will bend about 45 degrees . The post
is a bit larger so the the pitman will need reaming. the threads are 7/8 vs 21mm for the Cruiser so the tubing can be of the same
outer dimension.
Bending a relay to clear parts will only do that...clear a part. It won't address steering issues that come with steep angles.
Bump steer happens when the front end compresses and the the relay rod, traveling in an arc, changes the distance between point "a"
and "b" , "a" being the pitman and "b" the knuckle. The steeper the angle, the more the bump steer. Very soft suspension, like in a SOA
will dive more than stiff suspension. Shocks can help but a better relay angle is the safest answer. Bending the relay doesn't change
this. Whether the rod is straight, "S" shaped, a complete circle or a "W" the relationship between point "a" and "b" is all that matters.
With a steep angle, you slam on the brakes, the front dives and one of two things must happen..the steering wheel either moves left
or the wheels turn right ( opposite in Australia )

That is why i ended up going with high steer, though when i go to do my SOA again i would like to change how i go about it. What would you consider the best option to go with when upgrading steering for an SOA?

 

[Fieldtester96]

Any improperly designed and built suspension is unsafe.

My SOA I designed IS properly built and and safe, I daily drive it.
I spent about 5 years researching options, learning vehicle dynamics, fabrication, component choice, before I removed a single original bolt.

Id agree with you on that, if it wasnt for the vibrations in the drive shaft when i drove it really had nothing wrong with it that would stop me from driving it every day. The only problem i had is that i just physically seemed to big when driving which is fine for country roads and small towns but i go to school in a city so it would just make daily commuting worse. I definitely have a few more things to learn but with what ive learned through trial and error i know ill be able to do an SOA as a daily driver once i work out the kinks.

 

[Cruiserdrew]

No amount of good steering set up can change physics. It’s tall and tippy. Very tall. Very tippy. Unacceptable roll over risk for something you use daily. Consider going wider which helps a bit. 80 series rear axle is a good swap. But unless you need the highly specialized clearance SOA can give you, you are much better off spring under.

 

[Fieldtester96]

No amount of good steering set up can change physics. It’s tall and tippy. Very tall. Very tippy. Unacceptable roll over risk for something you use daily. Consider going wider which helps a bit. 80 series rear axle is a good swap. But unless you need the highly specialized clearance SOA can give you, you are much better off spring under.

Yeah i get that about it being tippy. I just noticed after my SOA when i test drove it i was going around S curves in the back woods and it really didnt seem all that bad. It probably would be worse on the highway but i rarely do highway driving with it even before the SOA. I get how the physics change and it definitely is gonna be less safe than a SUA, but i dont think it would be a bad daily driver though by the time im older my guess is i would get tired of how it handles.

 

[Randy88FJ62]

You gain nothing from a SOA if you are not going to rock crawl it hard. Stay SUA and you can still fit 35" tires.

Put your money into making it reliable rather than making it unsafe.

Show us a picture of you with your rig. I want to see the person making this thread.