So my wife and I were riding in our new to us 90 Samurai SJ SPOA and we couldn't help but notice the bone jarring bumps...  Is there something I should replace/upgrade on the Samurai to ease the bumps -- I was to told to buy new shocks that are 2" longer than the ones on there now?  I can only imagine how it's going to be off-road.

What do SPOA people do to cushion the blows?

I don't have anything fancy...  the only modification it has is a SPOA.  

What is your tire pressure? and what size are they?

31 x 10.50 x 15

Goodyear Wrangler

38psi



 

Is it actually the bone-jarring ride or the violent twitching of the steering wheel?

steering wheel was really good, actually.  From posts here i was expecting a twisting-action-packed ride.

It was from the bumps and shallow pot holes...nothing gave.  The guy I bought it from said buy new shocks that are 2" longer than the ones currently on there.  The current shocks look ancient -- they may or may not be the proper length.  What are the proper length shocks for a SPOA setup?

I was made aware of pads that go between the springs.... and found out that newer springs may be more comfortable and can go that route too -- if needed. 

Seems like new springs are a cost-efficient way of lifting the vehicle? One day I would like to go to 33" tires -- maybe I can just get new springs that are just talll enough to run 33s without rubbing. Maybe it doesn't work like that?

Reduce the tire pressure to about 15 PSI and see if it helps, those tires are pumped up way too high

Reduce the tire pressure to about 15 PSI and see if it helps, those tires are pumped up way too high

Dang!

I should have read the post closer!

38 PSI will knock your fillings out!

I would go a bit higher like 20-25 PSI - but 38 is way too high!

Adjust the pressure down until you get the ride you want.

Remember- Tire pressure is related to vehicle weight.  You are slapping big tires on a small truck so it does not take much air to get the amount of sidewall stability as the same tire on a heavier vehicle. 

Ha...see - I wasn't exaggerating....while driving around town and onto my driveway I was thinking to myself ok so something has to be missing because I can't see too many people getting pumped up to ride in a samurai if it took bumps like this one. I'll reduce the psi and check out the shock situation

What size shock do people run on a spoa ?

Somebody hep me out here ...

SPOA is essentially moving the axle from one side of the spring to the other - from above to below.  Assuming that the shock remains attached to the same "spring seat" (this is what the parts catalogue calls it), and the spring seat is transferred to the other side of the spring (from below to above) - why would a longer shock be needed?

What am I missing?

As you all would expect dropping tire pressure to 22.5lbs made a huge difference

Went from wearing a mouth piece to sipping on a diet coke

As a side note, the tire pressure for a 205 75 15 tire was 23 PSI on the 89' Sidekick.

You can do a chalk test, which is draw a chalk line across the tire tread, drive it
a short distance and check for the chalk, reduce the tire pressure until it wears
off evenly across the tread width, this will be your new on road tire pressure

Wild

The size of shocks you run on a SPOA depends on how it is built.  When I build a SPOA conversion I tend to flip the spring pads so the shock is mounted above the axle.  This allows me to use the stock shocks and keep them away from rocks.  A longer shock is not needed.

Later I did an RUF conversion, when moving the axle forward I had to install a new shock tower.  So I pulled off the shocks, measured my vehicle at full extension and full compression and found that shocks from the front of an F-250 worked perfectly.  Now I run shocks from an F-250 on the front and stock sized shocks in the rear.

zuk88, another Samurai owner in my club, mounted his shocks on the bottom of the axle and used a custom shock mount.  He requires a much taller shock then I do for my SJ.

So what sized shock is needed for your rig?  Without measuring it I have no idea. 

Today for the first time I drove my Samurai with the mini spool locked rear. The sammy is only used in the city / pavement when it is heading out to, or coming back from, the desert or mountains. I'd never consider a locked rear for a daily driver. Locked front sounds very hard to drive to me. When I turn now on the pavement it sounds like a dog barking. Kind of funny how people turn to check out where that sick dog barking sound is coming from!

I run 22 PSI in the city and much lower once we get off the pavement. I have 32" tires.

As a side note, the tire pressure for a 205 75 15 tire was 23 PSI on the 89' Sidekick.

You can do a chalk test, which is draw a chalk line across the tire tread, drive it
a short distance and check for the chalk, reduce the tire pressure until it wears
off evenly across the tread width, this will be your new on road tire pressure

Wild

another side note would be to first look on the sidewall and see what the max tire preasure is and if you go too much below that you are going to prematurely ware your tires out on paved roads.

mbruce: go with the chalk test that wildgoody suggested. and never ever get close to "max" rated tire pressure. those ratings are for a average vehicle weight rating (prob. in 4k range) not a 2K pound rig. even constant down pressure with only 2K sitting atop it will not reduce tire life to a point that having it ride like shit all the time is worth it or even worth a second thought. 

a good alignment and good shocks will do more good for tire life than 105 psi of tire pressure. (and yes I have seen 10 ply's on little suv's with 16" wheels).