Finally I began my coil spring conversion!!

[denis]

what oil level are you running ? You can play with to change the place where the hyperbolic curve verticalizes. More oil = less air = less travel for the same pressure increase. HTH.
For the N2 try to see if you can bolt your regulator onto a standard welding/ industrial gas bottle, maybe even get a male/male or female/femame adapter to reinflate your own bottle form a welding shop or tire place nearby.

[denis]

this article is fairly well written if you had not szeen it yet :
http://www.pirate4x4.com/tech/billav...hox/index.html

[Francesco_from_Italy]

Thanx Dennis, I've read the article.

I didn't touch the oil level, I only added or took out gas pressure; but its very intersting if there is the chance to set the height also operating on the oil level and not only on the gas pressure...

Talking to a friend who's doing quite the same job we tought that in the rear side I could keep running 2.0" shocks (I will not add any weight, except the spare wheel) and of course in the front the 2.5" are the only way (I found a pair of brand new 2,5" air shocks by Fox, 670 $).

Do you think that this solution could work? 2.0" in the rear and 2.5" in the front??
Anyway, I tried to calculate once again the sprung weight of the FJ and seems strange that, at least in the rear side, they can hardly hold the load...

Francesco

[denis]

Do you know how much oil you got them with ? I think I read somewhere a guy saying his airshocks were delivered with the absolute minimum amount of oil in his.
I would try to find the ins and outs of the current issue before spending any more money. Try draining the shocks to see how much oil you have in them, and start from a known basis, play with the worksheet and fiddle with them, odds are you will be able to achieve some decent results.
HTH

[Francesco_from_Italy]

That's a thing that I ignored: also oil level could influence the height of shocks.

In effect I don't know how much oil is in them by now; how could I do to set the oil level? Is there an indicator or something like that...?

Anyway, I argue that in the front 2.5" are th best, maybe only, solution. I'll order them right tomorrow...

Francesco

[Francesco_from_Italy]

Here I am again, this time with some good news and bad news...let's start with the good one!

The car is almost complete: the weldings are done, I've got only the last things to do (rear bumpstops, silencer etc.) but the car is already able to run.

These are some pics from a little test I did in the garden of my house; the first three are about the rear axle; as you can see it has a good ride and I can see that the work came out fine (the ride of the shocks is about 33 cm/13": is 4,5 cm fully compressed and 38 cm fully extended):







And now the bad news: the front axle is quite stationary; the ride of the front shocks is less than 15 cm/6":



I think that the the problem is due to the links of the radius arms: they tie too much the movement.
Now, the solutions could be two:

- the first is to modify these links, maybe putting round uniballs instead of the rubber (uniball like these: )

- the second is to change radically the arms system: leave the radius arms but cut away the front bolt and add an arm on the top of the axle, building something like a 3 link.

Now, what do you think about these suggestions? Can you tell me other options (please consider that the whole work is done and I wouldn't change it too much...).

Please help me, once again!

Francesco

[denis]

start all over

j/k

Find a bigger bump, or even better, a forklift so that you can max out your articulation. Typically the rear articulates before the front, but that does not neccesarily mean the front binds. On the pictures it seems you are nowhere close to your max. travel.

[BiffS]

Can't see it from your pictures, but if there's 2 wrap arms on the front, that will cause it to bind a bit. I ended up with only one on my 3 linked 3 runner.

Funny the rear end set up on your truck looks strangely familiar. . .

Remember that it will take a few trail runs to settle to final height with the nitro and oil. The shox will also behave like they have zero rebound control for the first while.

Mine had the gangsta lean after taking a corner on the street for a few weeks of driving.

you'd take a left and the truck would lean to the left, and stay that way. Looked like I was hittin the switches!

[Francesco_from_Italy]

So what do you suggest? To built a third arm and remove the front bolts of the radius arms?

By now I just tried to remove the front bolt of just one of the RA and the axle moved much better; but do you think I can drive like that, without a bolt?

Francesco

[alkaline747trio]

That set-up isn't optimal, but yes you can drive on it. You should consider a rear sway bar to help balance the travel, but a radius arm setup on a SWB 40 isn't ever going to be ideal.

[Francesco_from_Italy]

I've found this page: http://www.4x4review.com/tech/fj80-3Link.asp

That's more or lesso what I wanted to do.

Francesco

[Francesco_from_Italy]

The third link project is going on, but I found a few problems also there (of course...).
Firts of all, here there are a couple of pics of what I get from the modification:





The travel is much better than with the radius arms; now is about 12" so it has been doubled.

Let's come to the matters: the upper arm (by the way: 1,25" joint and 1,75" rod, do you think it's heavy enought?) when the passenger side wheel is compressed touches the panhard:





My solution is to make the axle link about 1" taller since I have enough room underneath the engine fan; do you think that the trick could work?

Any other suggestion about the work?

Francesco

[ToyotaNick]

Originally Posted by Francesco_from_Italy

Here I am again, this time with some good news and bad news...let's start with the good one!

The car is almost complete: the weldings are done, I've got only the last things to do (rear bumpstops, silencer etc.) but the car is already able to run.

These are some pics from a little test I did in the garden of my house; the first three are about the rear axle; as you can see it has a good ride and I can see that the work came out fine (the ride of the shocks is about 33 cm/13": is 4,5 cm fully compressed and 38 cm fully extended):







And now the bad news: the front axle is quite stationary; the ride of the front shocks is less than 15 cm/6":



I think that the the problem is due to the links of the radius arms: they tie too much the movement.
Now, the solutions could be two:

- the first is to modify these links, maybe putting round uniballs instead of the rubber (uniball like these: )

- the second is to change radically the arms system: leave the radius arms but cut away the front bolt and add an arm on the top of the axle, building something like a 3 link.

Now, what do you think about these suggestions? Can you tell me other options (please consider that the whole work is done and I wouldn't change it too much...).

Please help me, once again!

Francesco

NOW THATS WHAT I HAVE ALWAYS WANTED TO SEE AN FJ DO! theres alot of fj's in lafayette louisiana that have lifts and are very pretty but nothin with that kind of flex!

[Francesco_from_Italy]

Ehehe thanx a lot Nick, that's the result of a very hard and long work...and this isn't still finished.

Coming back to my question, I think I can move the 3rd arm link 1,5" upper, so the gap between lower and upper arms would be more or less 10/10,5" (that according to this review 4X4REVIEW.COM: Tech - Toyotal FJ80 Land Cruiser - 3 Link Front Suspension w/ Panhard would be the right quote for 38"/40" wheels running) and there wouldn't be any interference between the 3rd arm and panhard.

Francesco

[Francesco_from_Italy]

ok, i almost see the light!

So, this is the situation now:



The pic has been taken yesterday; as you can see the car is almost finished; but trying the shocks I noticed that the front ones are maybe too tought, specially in compression.
What I ask you is: wich elements influence the hardness? just the nitrogen pression or also the oli level?
What can I do to make the shocks a little bit softer to increase the flexibility, considering that I wouldn't change the car's height that I just set???

Thanks for you help!!!

Francesco

[Francesco_from_Italy]

Anybody can help me??

To soften the shocks what can I do? Lower the oil level maybe?

[Pacer]

Francesco, I have no experience with air shocks specifically, but I have read here that they settle after a while.

With my Motorcycle front ends I have found that too much oil will make the front suspension VERY stiff. I have found that that if I take the end cap off, the spring out and fully compress the shock there should be no oil spilling out. that makes them nice.

Did you add oil to the shocks?

[outbackoffroadgear]

If I under stand you you want to make your suspension softer so it will flex better.
Well the nitrogen in your shocks only give you ride height if you want your front to flex more you will have to 3 link or 4 link it. The 80 control arms will not let you get that kind of flex we have tried every thing and the only way your front will flex like your rear is link the front throw the 80 arms out your wasting your time


I hope this helps

[outbackoffroadgear]

you need to also move your track bar out front of the axle not behind the axle

[bustanutley]

I don’t quit understand what you are looking to change in the characteristics of your shocks?

If they have too much dampening you need to change the weight of the oil to something lighter.

If they are too stiff at the end of the travel of the shock you need to lower the level of the oil. (you don’t want the shock to ever actually bottom out though..)

If they are too stiff at ride height lower shock pressure and raise oil level to keep them from bottoming.

Everything you do to the shocks is tied together so if you change one thing another will change, it will take some tinkering, and I have never tuned shocks on a vehicle, my experience is only with downhill mountain bikes which use all the same components on a smaller scale.

[Francesco_from_Italy]

Outback I built a 3link in the front and 4link in the rear, I don't think that the problem are bars and arms.

Thanks to Busta and Pacer, that's exactly what I wanted to know: I just want to gain flexibility without changing the N2 pressure, and basing on your suggestions seems that this is possible just lowering the oil level, isn't it?
So, the front shocks pressure is now around 180 PSI; taking off some oil I should make the suspenion flex more than they do now without operating on the N2 pressure!

Francesco

[Francesco_from_Italy]

Outbakc, I forgot to tell you that the previous pics refer to the old suspension configurations, with the LJ 70's radius arms; now I put a 3link in the front!
By the way, wich is the track bar you're talkin about?

[Francesco_from_Italy]

Step by step I'm going to finish my work; yesterday I built the strut bar that was ncessary to make the front suspensions strong enought.
Here it is a pic of the bar (the central bolt needs to set bar's width):



I previously also tried to move a little bit the suspensions, putting out some N2 and this is the result:



Not bad; the car is not high as I wanted but I hope I'll find the right compromise; plus, I still have to set the oil level and this could make me gain a few more centimeters of compression.

Francesco

[Tapage]

Your strut looks heavy .. but make little complicated work over the engine and pull out .. ? ( without pull the hole front grill and rad )

[Francesco_from_Italy]

From the pic is not clear, but it will be possible to remove the bar; the links will be bolted and not welded (by now I made a few little weldings just to work better while building the bar).

Francesco

[Francesco_from_Italy]

Just to let you know, yesterday I went out for the firts test of my air shocked FJ; here there are a few pics:









The firts impression is very good; nothing has broken and everything seems to work fine. The only thing that didn't conviced me is the shocks setting: the work fine in every situation except laterals: they go too much along with the body movements and often the car is near to turn over. I think that this is due to the shocks setting, they probably have to be harder; I'll try different regulations in the future to chose the best one.

Francesco

[kc_chevota]

i had to add a sway bar to the rear on my mom's truggy (air shocked 4 link) rolled first time out. now it's great and the bar didnt hurt the travel much at all.