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Coil over size?

B

Boss Cherokee

NAXJA Forum User
Location
Riverside Calif.
Finally decided on going coil over but do not know much about them being old school and all! I found a brand new set of 10" Fox air shocks and I'm wondering if that might work also. I can get swayaway's for $315 10" travel apiece at 2.0 but I'm not sure if I should go with 2.5's and more travel! This is what stopped me last time! All the confusion of which which to pull the trigger on? Unfortunetly, it's time to pick a road! Cons and pros on air shock vs spring coils would help, as well as shock size and coil weight rate for a 96 XJ with 36/35 tires (2 sets), 6k winch and bumper 9" w/44 outer. If there is a post on this already please send me a link!
Oh and thanks to the board on getting my red status taken care of Dave B and G.Sequoia!
 
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You will have to measure for length on your Jeep. Beyond that it's just a matter of determining use and what is available in the lengths you require. But I think you need more study time. You asking allot of either/or questions on subjects that do not have either/or answers. Ie an air shock might be able to be used as the shock in a coil over, but NOT as a replacement for the coils of a coil over.
 
He's flat wrong and doesn't have a clue what an air shock is. Up front on a full bodied xj you are asking a lot of an air shock to handle the weight even in a 2.5". Out back a 2.0 would be marginal, which is why I'm building mine with tk1 racing 2.25" air shocks in the rear. I went with 14" travel and built shock hoops through the floor. Up front anything longer than 10-12" would be a waste as the steering usually binds before you get that much travel. If you can afford it I'd recommend coilovers for tunabilty and weight capacity at least up front.
 
could he use the ori air struts. they can support 1900lbs per shock?
 
I just threw the air Foxs' in there because there was a set for sale cheap on CL. Ok I"m looking at swayaways 2.5 10" or 12", so I'm wondering what coil rate for both primary and secondary and do I even need to go secondary?
 
Assume you are talking about mounting in the front? It's a fair bit of work so I wouldn't go through it unless you are going to mount a longer travel CO. I'm running 14" Fox 2.0 CO's. They do fine for my mostly crawling wheeling style and some light higher speed stuff, but if I was into more high speed stuff I'd go 2.5's. Forget airshocks unless you just plan to crawl and are on a super tight budget. CO's are far more tunable.

Just like any shock, you have to determine how much up/down travel at ride height and plan your mounts accordingly. Taking into account the tire does not hit them at flex and they don't hit the frame on droop. I think mine are angled out about 10 deg so the tire clears on flex. Spring rates are determined by your rig's cornerweights, how much uptravel at ride height, and how you plan on using your rig. You can do a double or triple sping set up. I'm running 5" uptravel so using a shorter top coil allows me to have a stiffer (128 lbs/in) rate at that height. But the shorter coil unseats at droop so to keep tension on the springs you have to run a light 3rd spring. It basically does not add any rate but keeps things tensioned when at full droop. If I were to run a longer (say 2" more) upper spring, I would need a lighter spring rate to get to the same ride height since the spring would have to compress 2" more. For example, if the front cornerweights of the rig are 700 lbs and on a 14" CO with 2 14" springs I had to compress the springs 7" to get to my desired ride height, I would need a rate of 100 lbs/in (700/7). If I used 12" and a 14" springs instead, I now only have to compress the springs 5" to get to the same ride height so the spring rate would need to be 140 (700/5). So that's why it's important to know your cornerweight before you start to figure out your spring rate. Combined rate of the springs is calculated by the formula of (R1*R2)/(R1+R2). Hope that makes some sense and helps you out a bit.
 
Thanx for taking the time and effort to explain it! Seems pretty simple the way you said it! My experience has been in coils only such as the 5 link I did for my van. I just call the spring manufacturer I use to use. I would just him what make it was, what motor, what lift and stock or winch bumper ect.. and he would send me coils! I am also going to go to Pirate and read what they got and decide on coils or CO's. Thanks again!
 
Boss Cherokee said:
Thanx for taking the time and effort to explain it! Seems pretty simple the way you said it! My experience has been in coils only such as the 5 link I did for my van. I just call the spring manufacturer I use to use. I would just him what make it was, what motor, what lift and stock or winch bumper ect.. and he would send me coils! I am also going to go to Pirate and read what they got and decide on coils or CO's. Thanks again!
Click to expand...

Glad it helps. Guess I should have also mentioned the combined rate is only in play until the lower spring hits the slider stop, then the spring rate goes purely to the bottom rate. So in a 200 over 300 lb spring set up, the combined rate is 120 until the spring hits the slide stop then the rate goes to 300. Important consideration to absorb bigger hits. In general anything less than a combined 100 lbs/in rate on a full bodied XJ is probably going to be too light unless it's just a slinky crawler. I'm running 225/300 rate springs. Although I'm far from "full bodied", I have tubework, heavy bumper, winch, etc. that puts me heavier than stock.
 
I run a 200/200 on my pig of an MJ and it's perfect (100 lbs/in combined rate). I'd guess my MJ is just north of 5k lbs.

If you have coilovers, prepare to get into the shocks and mess with the valving as well.
 
garrett83 said:
Why are you looking to switch to coil overs?
Click to expand...

Time for a change! The radius arms were fine for 23 years of wheeling everything from Bull to the Hammers. As much crap on the width that everyone gave me about the 36x15.50x15's, I think the traction as well as my 85 XJ with the V8 (the axles were under that for 20 of the years), took a toll on the radius arms! With that being said I still believe for mild wheeling the radius arms are a great inexpensive easy swap for the novice. Over the past 5-7 years the trails have gotten wicked. The hammers are 5 times harder with all the big tire rigs and buggies tearing them up. I wheeled Bull in the winter and again in the spring with my brother in law following, for me to tug him, in a early stock geared Bronco with 33's and a 3" lift 15 years ago. Why CO's I guess it's time. Don't get me wrong G Dog I will use the coils if I come up with a good plan. I have 12" & 14" Bilstein shocks sitting in the garage, so if the budget breaks I stay springs. This last winter was bad! No snow no O.T. I lost probably 10K-16K in potential income from lost O.T. So I hope this makes sense on WHY! ARE you still coils or did you go Coil over?? How's the lady?
 
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Gasman said:
Glad it helps. Guess I should have also mentioned the combined rate is only in play until the lower spring hits the slider stop, then the spring rate goes purely to the bottom rate. So in a 200 over 300 lb spring set up, the combined rate is 120 until the spring hits the slide stop then the rate goes to 300. Important consideration to absorb bigger hits. In general anything less than a combined 100 lbs/in rate on a full bodied XJ is probably going to be too light unless it's just a slinky crawler. I'm running 225/300 rate springs. Although I'm far from "full bodied", I have tubework, heavy bumper, winch, etc. that puts me heavier than stock.
Click to expand...

Your combo sounds like a good place to start. I am full bodied, full winch bumper (front and rear) as well as winches. The lighter one (6000) in front. 9" front 44 outer on 36x15.50 aluminum wheels and a set of bead lock aluminum wheels on 35 Parnelli's. If I go this route it will probably be 10-12" Swayaways, at $300.00 +75.00 spring kit + springs. Unless anyone has a bother Idea!
 
disclaimer: I am in no way saying you should or should not run coilovers.

you don't need coilovers to get rid of your radius arms. it is perfectly possible to run a very successful suspension with coils and shocks.

however, if you do go with coilovers, get at least a 2.5" up front. your rig is heavy enough a 2.0 will be too small.


Boss Cherokee said:
Yeah I KNOW thats why I want to stay coils!
Click to expand...

you should be having your shocks tuned regardless of whether or not they are coilovers or coil/spring
 
rockclimber said:
disclaimer: I am in no way saying you should or should not run coilovers.

you don't need coilovers to get rid of your radius arms. it is perfectly possible to run a very successful suspension with coils and shocks.

however, if you do go with coilovers, get at least a 2.5" up front. your rig is heavy enough a 2.0 will be too small.




you should be having your shocks tuned regardless of whether or not they are coilovers or coil/spring
Click to expand...


I've decided on 2.5 already if I go that route.
"When you say I should be having my shocks tuned regardless!"
How do I tune a factory set of Bilsteins? Or do you mean the coil overs?

Not on you but It really makes me want to get in a time machine and go back when times were simple and I could just bolt a set of Rancho shocks go wheeling and call it good! I would not have to get a micrometer out and a degree dial indicator and find the square root of the astrological composition of the granite compound I'm going to crawl over!
At least you've convinced me to stay with coil springs. Up until you said I should tune my factory shocks then:explosion ! I've built houses, motors, Jeeps, 4x4 trucks, raced Baja, been to Europe-twice and the Carribean a dozen times, built a toy box, fixed a bridge, made a weather vein, flipped a few cars and houses, been to the grand canyon, surfed, water skied, snow boarded, skied, not to mention all the things I've forgotten to list, raised 2 boys and that statement my friend has made me feel like I have not accomplished anything in life!:speepin:
On the bright side you will save me a lot of money and sleepless nights, and for that I thank-you!
 
Nelson, you're crazy.

but its OK. :)

what I MEANT was that, whatever shock you decide to use, you should have it tuned for your rig. a quality rebuildable, tuned shock will go a long way to improving your ride, if that is what you are after. the only difference between say a fox 2.5" coilover and a fox 2.5 smoothbody shock is the fact that on the coilover the body is threaded. the shock is the same, and they are both tuned the same way

after having gone from bilstein to fox, I highly reccomend fox.
 
Boss Cherokee said:
Time for a change! The radius arms were fine for 23 years of wheeling everything from Bull to the Hammers. As much crap on the width that everyone gave me about the 36x15.50x15's, I think the traction as well as my 85 XJ with the V8 (the axles were under that for 20 of the years), took a toll on the radius arms! With that being said I still believe for mild wheeling the radius arms are a great inexpensive easy swap for the novice. Over the past 5-7 years the trails have gotten wicked. The hammers are 5 times harder with all the big tire rigs and buggies tearing them up. I wheeled Bull in the winter and again in the spring with my brother in law following, for me to tug him, in a early stock geared Bronco with 33's and a 3" lift 15 years ago. Why CO's I guess it's time. Don't get me wrong G Dog I will use the coils if I come up with a good plan. I have 12" & 14" Bilstein shocks sitting in the garage, so if the budget breaks I stay springs. This last winter was bad! No snow no O.T. I lost probably 10K-16K in potential income from lost O.T. So I hope this makes sense on WHY! ARE you still coils or did you go Coil over?? How's the lady?
Click to expand...

So did you ditch the radius arms?

Main reason I ask why coilovers is, there's really no need to spend the money on coilovers if you really don't need or won't use the performance abilities of a coilover. At the end of the day, you could be $1500 into a properly tuned set of coilovers for the front of your rig.

I'm running 2 5/8", 14" C/Os on the front of my rig, 150x14 over 200x16 springs, with about 1.5" of preload. This gives me 50/50 droop/up travel. I'm only using the springs to give me the ride height that I want and to provide Constant Spring pressure through the shocks travel. I will use the shock valving to control dampening forces.

Biggest things you need to consider on shock size is placement, ride height, up and down travel. This will dictate what length coilover you will need. Also, most will tell you that you need a 2.5" coilover.

Oh, and the wife is doing well, we just gave birth to our daughter a few weeks ago.
 
rockclimber said:
Nelson, you're crazy.

but its OK. :)

what I MEANT was that, whatever shock you decide to use, you should have it tuned for your rig. a quality rebuildable, tuned shock will go a long way to improving your ride, if that is what you are after. the only difference between say a fox 2.5" coilover and a fox 2.5 smoothbody shock is the fact that on the coilover the body is threaded. the shock is the same, and they are both tuned the same way

after having gone from bilstein to fox, I highly reccomend fox.
Click to expand...

10-4 on the Fox any comment on Swayaway?
 
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