SPOA vs SPUA

[Zukman]

This is for us old school guys without coil springs pros and cons of each. You can also post up 3 link vs 4 link vs latter link.

[ARCTIC_EXPRESS]

3 link.... nothing better...but if it has to be leaf spring go spring over

[SHoppe715]

http://www.jpmagazine.com/techarticles/s...index.html

I like this article. Pretty down to earth for a magazine.

[SamuraiMike]

I look at this a little differently, to me, it’s more a question of how can I lift my rig and get the best overall bang for my $$$/time. Some rigs its best to utilize a spring over, others a spring under.
IMO the key is how the springs set under the rig. To get the best overall performance from leaves, you want them sitting nearly straight/flat with the vehicle weight on them; too much arch limits their ability to travel, causes a harsher ride, and makes the vehicle "squirrely" on pavement.

If you want to run huge tires, or for pure off-road, the spring over is the way to go, it adds leverage, which increases "flex" and keeps all 4 tires on the ground. There is a price... The increased leverage seriously effects handling, exadurating (sp) body roll, track-ability, and axle wrap. To counter this, most companies use stiffer springs, which ride harsher & limit flex. I blew out 5 rear driveshaft’s on my little 68 HP Sami & turned a stock set of YJ springs into an "S" due to axle wrap while I was working the bugs out.
For the spring over, the best way to control this is using a traction bar on the rear axle and a panhard bar on the front. This adds complexity to the suspension & if done improperly, will limit offroad ability. My Sami was spring over, with the lockers and tires, it performed well offroad, but was a real handful getting to and from the trail, I stopped using it as my daily driver, it was quite a workout.

A spring under system uses its own leverage to help control axle wrap, body roll, wondering, and bad road manners. For a daily driver that needs a moderate lift, the springs will set flat/straight, and you’re on a budget, spring under will be your best bet. It is a simpler way to "bulletproof" your rig. The trade off is losing ground clearance (at the spring) and a little less flex.

Aren't you building 2 Sami's??? Do one of each & let us know!!!! LOL!!!

Just my 2 cents

[TJVigilante]

Wouldn't a sway bar such as the Currie Anti-Rock or Sway-lok help avoid the excess body roll on the highway, without requiring the front panhard bar? You don't really need to locate the axle, the leaf springs do that for you...you just want to limit bodyroll and an adjustable sway bar should do the trick. I'd still put a traction bar in the rear to limit axle wrap...and one on the front for larger diameter tires, more as a safety mechanism.

[SamuraiMike]

Yes, the sway bar will dramatically help control body roll, but what i found on my Sami, the axle was actually moving from side to side, flexing the springs as it did this. This caused a lot of "wondering" on the road, felt more like I was "guiding" the rig than controlling it. A lot of people call it a "floating" feel... Doesn't inspire confidence on the road....
SuzukiDave put a panhard bar on his Sami and said it felt like a sports car! LOL!!!

But all of this adds $$$ to the build.

I read SHoppe715's reference arcticle and it makes a lot of sence. Good reference!!!

[Zukman]

I am thinking about a over in the front and under on the back. You would have the clearance for the front axle and less to no wheel hop in the rear. Yes, the front axle on a zuk moves side to side pull the doors off and get in a big parking lot with other cars and drive in a circle, hold the wheel turned and very the throttle input it. There is alot of movement!

[TJVigilante]

See I'm a coil-link guy, I didn't take into account bushing movement. Yikes.

[JeepMadness1979]

I am thinking about a over in the front and under on the back. You would have the clearance for the front axle and less to no wheel hop in the rear. Yes, the front axle on a zuk moves side to side pull the doors off and get in a big parking lot with other cars and drive in a circle, hold the wheel turned and very the throttle input it. There is alot of movement!

Do over on both axels and we can make a track bars for the rear. That is what I am going to do for my rig, If the aluminium bars that I have for my jeep are to short we could use them on the zuki. It would work and look sweet

[Zukman]

As most of you know i went spring over, at first i short shocked it until i could find so cheap shocks. At Carl's Blazer build i found so used ahocks laying around the craft shop so i picked up a a arm full and set to work checking lenghs and valving. I mounted up them closest ones up and have two trail rides on them. So for the body roll on the street takes some getting use too but offroad there sweet! I don't have spring wrap yet but more testing is needed. Front travel is limited by short springs ( That will be taken care of with rear springs up front ).

[Angler]

If you put a traction bar on put it on the right side of the vehicle, I put mine on the left because I got cheap and did not want to mess with the exaust, and under acceleration you could frrl the Jeep actually torqeing to the passanger side, it was very noticeable also to others on the road. My current Jeep already is SOA I am going to ad a traction bar to it when I swap in the Izusu D44 rear.

[Zukman]

Sammy's have off set diffs i can center the bar if i need it.