4 link rear, Fox shox on a 92 XJ

[flexj]

Pics are here if anyone is interested. http://community.webshots.com/user/hamyscj go into the rebirth II album.

It's not running yet, so no real testing, but it flexes real nice in the shop. I welcome comments, concerns and critiques.

Steve.

[hpi_jeep]

looks pretty damn good to me!


as everyone says: this pic is worhtless without at least one good poser flex shot.

[BrettM]

I gave you some feedback on PBB also, you need to move the airshox out to the ends of the axle for stability, or run a swaybar.

[snoopy]

How do you like them so far. I'm throwing on a set of those next week!

What preasure/oil combo did you use?

[flexj]

How do you like them so far. I'm throwing on a set of those next week!

What preasure/oil combo did you use?

So far I love them...they look great sitting in the shop :thumbup:

As far as pressure, I got 200 psi and have 6" of shaft(average, right??) showing. Oil, I have no clue. I lost some when I let the factory charge out and haven't put any back in yet. They def. need some oil, though. I deal with that when I'm ready to drive it.

[snoopy]

keep up updated!

[flexj]

I gave you some feedback on PBB also, you need to move the airshox out to the ends of the axle for stability, or run a swaybar.

Weeelllll, I can't move the shocks out further without cutting into the frame more. And at this point, I'm unwilling to do that. I guess I'll wait and see how it handles and deal with issues as they arise. Thanks for the heads up.

[ladywolf]

looks good to me so far, but i'm a "noob"


Kris

[scampbell53]

Looks good so far! A couple questions first, how high are you going and how far back did you move the rear axle? For a little tie in on the top I bolted my cage into the seat belt mounts . I do like the four link mounts and the angles. My next question, this is lack of knowledge on my part, I thought air shocks are for light weight rigs. I know my XJ has turned into a lead sled, and I have ripped everything out except the steering wheel. So when you find what setting works best for the shocks let us all know. Can't wait to see the finished product!

[XJoachim]

I'm in the process of fitting 9100 Bilstein rockcrawlers and i won't angle them this much and will also move them a lot more outwards than you did. In my calculations they would require stiffer springs and a stiffer valving to achieve the same results the more i move them inwards and the more angle they have.

[flexj]

Looks good so far! A couple questions first, how high are you going and how far back did you move the rear axle? For a little tie in on the top I bolted my cage into the seat belt mounts . I do like the four link mounts and the angles. My next question, this is lack of knowledge on my part, I thought air shocks are for light weight rigs. I know my XJ has turned into a lead sled, and I have ripped everything out except the steering wheel. So when you find what setting works best for the shocks let us all know. Can't wait to see the finished product!

If my calculations are correct, I went for 6" of lift. I did not move the axle back any. It might have ended up back alittle since I have some ability to move it by adjusting out the heims.

Yes, the weight issue. I am pretty confident that my sprung weight in the rear is less that 2k lbs. Until it is mobile, I have no way of getting it to a scales.

I'd like to see pics of your cage if you have some.

If I have a fault(my wife would say "which one?"), it would be to settle for "good enough". My goal is to not let that happen with the rear shocks. I am going to do my best to get them dialed in right and not to settle for good enough. Keep checking the webshot website as I post new pics as I get things accomplished on the jeep. I'll have the fuel cell in and hopefully plummed and running this week.

[flexj]

I'm in the process of fitting 9100 Bilstein rockcrawlers and i won't angle them this much and will also move them a lot more outwards than you did. In my calculations they would require stiffer springs and a stiffer valving to achieve the same results the more i move them inwards and the more angle they have.

One thing I found out while mocking these in was that as the axle articulates, the shock coming up also seems to move outward. I was hitting the frame at early stages of up travel. I cut into the frame as much as I thought I could while still maintaining frame integrity. Maybe I will cut more and move the lower shock mount out, but not right now. The other thing I fould out, was that with these air shocks, they work alittle more smoothly towards the end of the travel than they do when they are mounted straight up and down.

How do you plan on getting around the frame? I'd be real interested in seeing some pics of your too. It's never too late to modify if someone figures out a more effective way.

[snoopy]

My next question, this is lack of knowledge on my part, I thought air shocks are for light weight rigs. I know my XJ has turned into a lead sled, and I have ripped everything out except the steering wheel. So when you find what setting works best for the shocks let us all know.
Billavista wrote up his use of the AirShocks on his 4,700 lb buggy. Check it out: http://www.pirate4x4.com/tech/billavista/PR-Airshox/index.html

[flexj]

That's the article that got me from coilovers to these air shocks. I hope I did the right thing.

[Goatman]

I don't think there's any question that your shocks are too close together. It's yet to be determined how much of a stability problem you'll end up having, but it will be there. You can compensate for it by stiffening the shocks up and by stiffening up the front, but that can hurt the ride quality, or you can run a sway bar in the rear.

Some nice work there, too bad you couldn't figure out a way to have better shock placement.

[BrettM]

One thing I found out while mocking these in was that as the axle articulates, the shock coming up also seems to move outward. I was hitting the frame at early stages of up travel. I cut into the frame as much as I thought I could while still maintaining frame integrity. Maybe I will cut more and move the lower shock mount out, but not right now. The other thing I fould out, was that with these air shocks, they work alittle more smoothly towards the end of the travel than they do when they are mounted straight up and down.

How do you plan on getting around the frame? I'd be real interested in seeing some pics of your too. It's never too late to modify if someone figures out a more effective way.
what about mounting them to the outside of your cage, through the already opened fenders, to the very outer edge of the axle, just 1 inch inside the disc?

[vintagespeed]

....The other thing I fould out, was that with these air shocks, they work alittle more smoothly towards the end of the travel than they do when they are mounted straight up and down.

This is because they're losing spring rate. I dont know the figures for airshox but if you have a 200lb/in single coil coilover mounted vertically it takes 200lb to compress it 1 inch. The further you lean the shock away from vertical, the more spring rate you lose and less force is required to compress it.

There are calculators for this out on the web, and YES I know you dont have springs but it's the same issue.

-jb

[BrettM]

one thing about the air shox is that the "springrate" increases greatly at the end of travel, so it makes sense that people like the last few inches of travel better with them angled. several of the guys that have really researched the airshox have tried coming up with a good way to compare the "springrate" to normal spring rates, but it just doesn't work. to chart travel vs. springrate would result in a very odd graph.

[vintagespeed]

I have read the Billavista article on POR about his work with AirShox on his non-street driven buggy. I hope they work well on this XJ.

Any shock mounted at an angle is not as effective as a vertically mounted shock, airshock, coilover shock, etc etc. And if the shocks are increasing in angle on compression rather than straightening then they are becoming less & less effective.

Hopefully the airshox stated increase in rate will compensate somewhat for this, but the tube buggies that I've seen with them are mounted vertically.

-jb

[BrettM]

I have read the Billavista article on POR about his work with AirShox on his non-street driven buggy.

but the tube buggies that I've seen with them are mounted vertically.

-jb

read it again, at the top of the article is Team Purple's buggy and the front and rear shocks are angled. I think Bill did his verticle because his is so heavy. I'm nearly certain all the "moon buggies" are running them angled.

http://www.campbellent.com/small%20pics/LS1%20MOON%20BUGGY0003.jpg

big thing though, is that they are ALL running them very far out on the axle.

[vintagespeed]

read it again, at the top of the article is Team Purple's buggy and the front and rear shocks are angled. I think Bill did his verticle because his is so heavy. I'm nearly certain all the "moon buggies" are running them angled.

http://www.campbellent.com/small%20pics/LS1%20MOON%20BUGGY0003.jpg

big thing though, is that they are ALL running them very far out on the axle.

I guess I need to spend less time actually BUILDING suspensions & more time web-wheeling to learn this much?

My coilovers are mounted at a 10deg. angle at ride height and are completely vertical at full stuff this way my spring rate(s) increase on compression and decrease on droop.

But I'm sure you're right.

-jb

[Goatman]

Will I get my hand slapped if I mention that BrettM has leaves front and rear? :greensmok

:gag: :gag:





:D :D

[SeanP]

Well I had a timely conversation with Tony K, the owner of Rock Equipment. Tony distributes SAW and the Fox Air shocks. He runs the Fox Air shocks on his buggies (he is fielding 4 buggies this year, including his new electric powered one), at about 20-25* angles. These shocks are best for vehicles running about 2500# or less. He also mentioned that the failure rate of these shocks at the comps this year is really high. More failed air shocks than cut sidewalls he says.

Personally, I wouldn't run these on an XJ. My rig weighs in at over 4700 pounds right now and there is no way the single fox airshock would control that weight. Two of them would but then you double the $$ and get to the point of getting a good non-emulsion CO setup.

SeanP

[flexj]

Well, I finally got enough done on it to get some real world testing. Surprising to me, the shocks worked awesome!! I couldn't have asked for a better working suspension. The ride is incredible, the flex is excellent. Even the reservations I had about them being angled in too much and mounted in too far seem unfounded. The rig seemed to have excellent stability on side hills and since it's a crawler, I don't seem to have the need for a swaybar. The weight issue isn't posing a problem either. I still don't know how much I weigh but the rear can't be much, there is nothing back there anymore. Anyway, check out the pics (http://community.webshots.com/album/242431436CRAuiy)

Hamy.

[Beezil]

I am wondering if you plotted your link geometry before you built?

what did you come up with?

[paul_xj04]

looks pretty fxxxing nice bro, i got some new iders.

are those 37" claws

[XJoachim]

Sorry, seems to me that the suspension is not balanced, too much flex in the rear compared to the front.

[ashmanjeepxj]

Is it squirly on turns on the street? If not, run what you brung.
If it does, get a sway bay. Many buggies run sway bars, and or a center limit strap to help with body roll.

Your biggest issue will be side hilling not flexing.

[Beezil]

Sorry, seems to me that the suspension is not balanced, too much flex in the rear compared to the front.

should be pretty darn easy to tune up.

I don't think any of us who 4-linked with 1/4-elip, coils or other got it on the first try.....it takes a buncha tinkerin to get it right.

the rear looks a little "soft" to me judging from the test run pics, but its pretty close.

whats the anti-squat on it?

[flexj]

I am wondering if you plotted your link geometry before you built?

what did you come up with?

Geometry....what's that??? Oh, you mean A2 + B2 = C2.

Actually, I read all the posts on PBB and here that I could find on the subject.I read BillaVista til I was crosseyed and I didn't understand 90% of it. So when I bought my air shox from PolyPerf., I talked to Dave and got the skinny. Uppers approx 70% length of lowers, keep them as parallel as possible and 8-9" of vert separation. I did that and I'm pleased with the results thus far. It doesn't seem to dive or lift at the wrong times. I don't go faster than 10-15 mph so the shock oil doesn't heat up. It seems stable on side hills. Already, it's 5 bazillion times better than the leafs that were on it. I'm redoing the cage and then we'll get it out for some more testing

Paul...thanks, take all the iders you want...yes, 37" claws, competition compound.

XJoachim...explain the negatives to me. Is it better to lift a tire or keep them on the ground? I couldn't say I noticed any negative affects of the rear being more flexy than the front. It is actually opposite of what it used to be with the leafs on the rear. And please, don't be sorry for your opinion. Alot of people have done this before me and I appreciate your response and taking the time to do so. I am looking into the 2.5" Air Shox for the front. Maybe 14" up there. That should balance it out some.


Ashman...I've never driven it on the street like this. I might have gotten it up to 20 or 25 on the driveway but no turns to speak of. It does squat and lift slightly when put into reverse/drive in low range. I think that is a result of the shock placement, amount of oil and overall characteristic of the air shock combined. What do you mean by "side hilling not flexing"? Do you think the weight of the rig will keep the down hill side shock compressed even when I'm tring to get up on a rock? Or the uphill side shock extending when the weight is taken off of it? I am eager to play around with side hilling some more, even to the point of tipping it to see how far it will actually go before tipping.

Back to Beezil...it might be alittle soft in the back. I am thinking of adding some more oil, but alittle hesitant. If I add too much then I have to drain the whole shock out and start over. They seem to work good now. What is the down side of being too soft? Explain how to figure antisquat and I'll let you know what it is.

Keep the comments coming guys, I appreciate it.

Hamy.

[BrettM]

there is a good 4 link calculator floating around on the Pirate board. you need to know where your COG is, then just punch in the numbers for where your links all mount.

[JeepFreak21]

Geometry....what's that??? Oh, you mean A2 + B2 = C2.

Actually, I read all the posts on PBB and here that I could find on the subject.I read BillaVista til I was crosseyed and I didn't understand 90% of it. So when I bought my air shox from PolyPerf., I talked to Dave and got the skinny. Uppers approx 70% length of lowers, keep them as parallel as possible and 8-9" of vert separation. I did that and I'm pleased with the results thus far. It doesn't seem to dive or lift at the wrong times. I don't go faster than 10-15 mph so the shock oil doesn't heat up. It seems stable on side hills. Already, it's 5 bazillion times better than the leafs that were on it. I'm redoing the cage and then we'll get it out for some more testing

Paul...thanks, take all the iders you want...yes, 37" claws, competition compound.

XJoachim...explain the negatives to me. Is it better to lift a tire or keep them on the ground? I couldn't say I noticed any negative affects of the rear being more flexy than the front. It is actually opposite of what it used to be with the leafs on the rear. And please, don't be sorry for your opinion. Alot of people have done this before me and I appreciate your response and taking the time to do so. I am looking into the 2.5" Air Shox for the front. Maybe 14" up there. That should balance it out some.


Ashman...I've never driven it on the street like this. I might have gotten it up to 20 or 25 on the driveway but no turns to speak of. It does squat and lift slightly when put into reverse/drive in low range. I think that is a result of the shock placement, amount of oil and overall characteristic of the air shock combined. What do you mean by "side hilling not flexing"? Do you think the weight of the rig will keep the down hill side shock compressed even when I'm tring to get up on a rock? Or the uphill side shock extending when the weight is taken off of it? I am eager to play around with side hilling some more, even to the point of tipping it to see how far it will actually go before tipping.

Back to Beezil...it might be alittle soft in the back. I am thinking of adding some more oil, but alittle hesitant. If I add too much then I have to drain the whole shock out and start over. They seem to work good now. What is the down side of being too soft? Explain how to figure antisquat and I'll let you know what it is.

Keep the comments coming guys, I appreciate it.

Hamy.


I believe that, if you're too soft, then you're not going to put enough weight/pressure on your drooping tire to get traction. You may not need to worry about that with a 100lbs wheel/tire combination or I could be completely wrong though :)
Billy

[flexj]

Yeah, them tires are heavy. They are heavy and they don't flex too well. I'm not sure what I'm going to do about that. Maybe groove them abit.
I haven't noticed any issues with the rear wheels not staying on the ground. I might add 10 or 15 cc's more oil and see what happens.

[paul_xj04]

just to add, i stop by S&N Fab here and there (i work right next to it) anyways im not sure if the name is right but i think its inverted 4link, they keep there upper links parallel with the inside of the frame rails (from the looks of it) and the lowers i a triangled design.

Hey flexj how much did those 37's cost ya and are they 15" rim

[paul_xj04]

also can i get a pic of the rear x-member or link mounts

Thanx

[flexj]

just to add, i stop by S&N Fab here and there (i work right next to it) anyways im not sure if the name is right but i think its inverted 4link, they keep there upper links parallel with the inside of the frame rails (from the looks of it) and the lowers i a triangled design.

Hey flexj how much did those 37's cost ya and are they 15" rim

Yeah, I've seen some guys trianglulate both lowers and uppers, or just one or the other. I guess it's preference.

As a MT dealer, I can give you prices right out of my book :)

Radials 37x13.50x15...$342
x17...$365

Bias 37x13.50x15...$262
x16...$275
x16.5...$277

Competition Compound 37x13.00x17...$308

Those are close, +/- a few $$ since my last price sheet came out.

Did you look on the community webshots site in any of my other folders for the pics you want? If they are not there, I'll try to post some up this week.

Hamy.

[paul_xj04]

yea i looked at all the pics and got partal veiw of it, just wondering if you had one of just it.

[ashmanjeepxj]

Ashman...I've never driven it on the street like this. I might have gotten it up to 20 or 25 on the driveway but no turns to speak of. It does squat and lift slightly when put into reverse/drive in low range. I think that is a result of the shock placement, amount of oil and overall characteristic of the air shock combined. What do you mean by "side hilling not flexing"? Do you think the weight of the rig will keep the down hill side shock compressed even when I'm tring to get up on a rock? Or the uphill side shock extending when the weight is taken off of it? I am eager to play around with side hilling some more, even to the point of tipping it to see how far it will actually go before tipping.

My first test run, pore side hilling ability. 3.5in air rams so much softer then 2in fox air shocks.

http://www.wheelingarizona.com/forums/files/000_0022_small.jpg
http://www.wheelingarizona.com/forums/files/000_0023_small.jpg
http://www.wheelingarizona.com/forums/files/1ashman_H2H.jpg

Mine was scary as hell on the street just before these first test runs. now Ive made my air springs stiffer, and feal safe on the street much more even flex front to rear very close to 50/50, less body roll, did much better side hilling.

If you have this type of issue, you can not make your air-spring stiffer (only your shock stiffter.) but you can add a sway bar. More Nitrogen will only give you a taller ride height not a stiffer spring. You could also fight this by adding a center limit strap, this will also help prlevent it from lifting-then leaning on turning or side hilling, and help fight exteme brake lift. A short limit strap may also help if you are having hopping issues on steep loose waterfall-hill climbs, related to link geometry but mostly drivng style IMO.

A limit strap and sway bar will give you a really soft but controlled ride. very common on the local extreme buggies around here.

[paul_xj04]

Yeah, I've seen some guys trianglulate both lowers and uppers, or just one or the other. I guess it's preference.

As a MT dealer, I can give you prices right out of my book :)

Radials 37x13.50x15...$342
x17...$365

Bias 37x13.50x15...$262
x16...$275
x16.5...$277

Competition Compound 37x13.00x17...$308

Those are close, +/- a few $$ since my last price sheet came out.

Did you look on the community webshots site in any of my other folders for the pics you want? If they are not there, I'll try to post some up this week.

Hamy.
another question, which are taller, the competion or the bias.

[flexj]

another question, which are taller, the competion or the bias.

That's a good question...my book lists the heights as 37". You and I both know that that is bunk. My comps are ~36" at 5 psi and weighted down.

[paul_xj04]

hmmm aight thanx