School me on Air shocks

[BiffS]

Air will hold more moisture that pure nitrogen. . . Also Nitrogen is less susceptible to heat changes. When i bomb down the logging roads in my truck, they get too hot to touch. (burning hot that is!)

Something to consider.

 

[cali-cruiser]

10 4

 

[Eskimo]

Does any one see a down side to charging these things with air besides the fact that most of the oxygen and other elements will bleed out more quickly than the nitrogen. The reason I ask is i've got a free source for over 300psi of air (The drill rig I work on), and 78% of air is nitrogen and 225psi is 78% of 300psi

Any thoughts?

Also, I was advised not to drive without the shocks being charged at all. meaning, don't tow it, either. So, I will be charging mine with air before I trailer the rig to get the shocks charged with n2.

 

[wngrog]

I love my air shocks.

I just bellied up for a spare though...losing one will kill a trip.

 

[cali-cruiser]

I just purchased a n2 bottle today and will be ordering the rest of the stuff for filling at home this week. now I just need to find a place to fill the bottle, anyone know of a place in northern california, I'm having trouble finding one,

 

[Eskimo]

Try looking for a welding supply house, they should be able to either help you, or point you in the right direction?

 

[cali-cruiser]

Found a guy just down the road that has a filling station and will see if they will fill my little bottle when they come next

 

[cali-cruiser]

biff, are you running bumpstops? is it ok to run these without them.

 

[BiffS]

no bumpstops. The airshox are naturally built that way: when you get to the last inch or two of the stroke, the "spring rate" goes up to something like 4000 LBS really fast. Never had a bump issue, mind you, i've never tried to jump it. . .

 

[cali-cruiser]

I got mine all finished up, All i've got to do is lengthen my driveshaft and throw on some limiting straps. I've to box in the hole in the floor too, but hey these things are awesome, the ride is smooth they have such a huge amount of travel it is amazing should be fun when I get it back out on the trail. plus the onroad handling really hasn't changed much except that when you slam on the brake the rear raises up about a foot and a half.

 

[Isotel]

You need a limiting strap on that sucker.. Nice Rig!

 

[cali-cruiser]

thanks

 

[Francesco_from_Italy]

I'm putting air shocks on my FJ 40.
I buyed 2.0" air shicks by Radflo (cheaper...) but now I'm quite late with my works: I finished the rear and I have still to do the panhard and the shocks' links on the front.
Unfortunately overhere I couldn't find the valve for the nitrogen regulation so I had to order the N2 kit from the US and that problem stretches the works time.

As everything will be ready I'll let you know haow they work!

Francesco

 

[Francesco_from_Italy]

Bad news about my air shocks:
yesterday I received the N2 kit and finally I was able to gas them and put under the car (only the rear axle).
I gassed them until a pressure of 480 PSI (that I guess is close to the maximum pressure) and drop the car; well, the shocks compressed for more than a half of their travel (the total travel is 16", they compressed for about 9").
What worries me is that the front side is likely heavier than the rear...

I asked to the RADFLO technician and he said that the maximum load is 900 lbs per shock. Now, my car is about 1800 kg (4000 lbs), assuming that axles/wheels are about 400 kg (900 lbs), the sprung weight is around 1400 kg (3000 lbs); 3000 lbs should be something like 1800 in the front and 1200 in the rear, so the rear shocks must hold "just" 600 lbs each.

One last thing: I'm afraid I'm still not completely able to use the recharge kit; I finished all the cylinder yesterday, trying to set the shocks; so its possible that the shocks are NOT really charged to a pressure of 480 PSI...

Concluding, what do you suggest to me? The 2.0" are too thin for my car? If someone has another experience with these shocks can help me, maybe telling wich is his setting pressure...?

I'm waiting for your precious help, since now I'm really in the s...

Francesco

 

[BiffS]

I read too much about the limitations of the 2.0 airshox, so i went 2.5 and never looked back. If you're running that pressure, that is definitely at the max of the shock (IIRC, 500 PSI max). also remember that it will take about a week or 6 wheeling trips for the shox to mix up the oil and nitro to achieve your real ride height. I started with 9" exposed shock on my 16" stroke Fox 2.5s, and they settled to about 5-6" running 195 PSI front and rear.

They settled about 4" once driven for a bit. When i first built the truck there was virtually NO return spring rate: taking a left, the truck leaned hard over to the left and STAYED there until i whipped the wheel to swing it back centered. After letting it sit for 2 weeks without driving and then driving up and down my bumpy alley, the phenomenon went away and it centers fine.

plan on re-adjusting the shock once it's settled in a bit. 480 PSI is too high for practical use. the photos i posted below while the truck was on it's own weight are at the factory 275 PSI from Poly Performance.

 

[Francesco_from_Italy]

So your opinion is that the 2.0" are definitely too thin for a 4000 lbs car?

About what you said, consider that now my rear shocks are set on 250/300 PSI and they are almost fully compressed (just 3/4" of travel left); that means that they are not strong enough...?

That would be a really big matter and, most of all, means more bucks flying away from my pocket!

I found these on Ebay, what'is your tought? http://cgi.ebay.com/ebaymotors/Fox-...ryZ33590QQihZ017QQitemZ270152217913QQtcZphoto

Francesco

 

[BiffS]

If you're planning on loading up a cruiser with hard top, people, gear, tools, etc, then it's not really a good idea to be working around the max limit of a suspension component. Remember that if it breaks or blows out, you'll have problems getting it home. Plus, if you're running a factory engine (2F , 3B, etc) that they weight almost 800 pounds fully equipped, not including a winch, tranny, body, chassis, etc.

There's some vendors on Pirate that will sell for $275 range each plus shipping, best to look there.

I guess that if it's not enough support, that you could 1/4 elliptical it too, but that defeats the purpose of a clean linked suspension.

 

[denis]

I read too much about the limitations of the 2.0 airshox, so i went 2.5 and never looked back. If you're running that pressure, that is definitely at the max of the shock (IIRC, 500 PSI max).

When I look at the physics I can't help but think the max. charging pressure is only a guideline.
With a 1.25" shaft you have about 1.23sq.in of rod section, and at 1000lbs (max weight rating) you have 815psi at ride height no matter how highit sit, how much charging pressure, or how much oil you have in them.

 

[BiffS]

500 PSI is the max static pressure that they are rated for. if you use the spring rate calculator from polyperformance or other places on the web, you'll see that the unloaded pressure at 250 PSI is about 100PSI, and max load pressure at full "compression" is about 4100 PSI, which is why the airshox have a basically unlimited feel through the travel range. On a hard bump or jump they have a built in soft bump when the fluid reaches virtual max range.

http://www.pirate4x4.com/tech/billavista/PR-Airshox/index.html

Airshox unload fairly easily, which is why i'm running currie anti-rock swaybars now.

In this vid, there's no swaybar on the rear and it basically just does it's own thing.

 

[Francesco_from_Italy]

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