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Originally posted by RJLougee
Hey guys, thought I'd wade in here a little bit and pass some info along about what I've learned.
1. Earl M. Jorgensen is usually the least expensive place I've found to buy steel. I know they've got a bunch of yards and they deliver to most of the smaller places we buy steel from. They will sell to the little guy as well and you can get them to deliver to your town on a normal run. My closest one is in Denver, but they come down here 2x week and will bring a couple sticks down for me. They also have better pricing at the 2 stick level, so if a couple guys are doing projects you can get a better deal. My 2x.25" DOM is just over $10 a foot.
2. Red Rocks 4x4 is the best price (by far) I've found for JJ and a lot of fab parts. Off-road Overstock is another good source, as well as Rough Stuff Specialties. Also look in the Vendor section on Pirate.
3. http://www.aladdinsteel.com/ Aladdin Steel is a good place to look up steel to figure available sizes. If you're looking for 2+" DOM with and ID of 1.5" you can get several sizes. Also gives the weight per foot so you can figure out how much more unsprung weight you're adding.
4. Fastenall had the best prices on jam nuts and will usually have what you need in a couple of days.
Now on to some theory.
I believe a FS of 2 is plenty for the lower links. I'm running .25" wall 2" OD DOM and that's pretty good for a 3K# buggy.
Upper links will only see compression/extension forces on them so lighter is more than enough. 2" is overkill to a high degree. I'm using 1.375 x .188 wall tube.
It's nice to have left and right threaded joints at all the links so you can adjust them on the fly. Of course, then you should have jam nuts on all the studs.
If you want to use angled lower links you need to have a fixed bushing at one end, otherwise the link will rotate and give you a bunch of rear steer. Why angle the link you ask? For better ground clearance while getting the mounting point as low as possible on the axle tube (rear below).
Put a winch in back so you can pull the body down so the coilovers don't unload as the rear unweights on steep downhills. Do you need it? Maybe, maybe not, depends on how well the suspension actually works.
Unless $$ is really an object, and I know it can be, just go coilovers right off the bat. Or even air shox IF YOU ARE WILLING/ABLE TO WORK ON THEM TO GET IT RIGHT. You'll stand a much better chance of getting a coilover right than air shox and you'll need to reoil/recharge several times. If you do a cost comparison you'll find that $400 a corner for coilovers is reasonable vs. say a nice set of Deaver leaf springs ($450 or better by the time you get them home) and a set of good shocks ($375/pair for some Bilstein 7100s). Looks like $800ish to me and the ride won't be as good.
When you're running your measurements and making calculations, ensure you're making them the correct way. If the lower link is 40" long and at a 15 degree angle, it's placement on the X axis isn't 40", it's more like 38.5".
Build adjustment into the mounting points at each end of the upper links, that will allow you to change your anti-squat to dial it into what you want as you learn.
My definition of Anti-squat: the way the rear suspension will move as accelerative forces are placed upon it. So, a really low AS will cause the rear end to SINK upon acceleration and a high AS will make it rise. Front suspension will also play a part in this.
Gotta run,
Joe
1. Earl M. Jorgensen is usually the least expensive place I've found to buy steel. I know they've got a bunch of yards and they deliver to most of the smaller places we buy steel from. They will sell to the little guy as well and you can get them to deliver to your town on a normal run. My closest one is in Denver, but they come down here 2x week and will bring a couple sticks down for me. They also have better pricing at the 2 stick level, so if a couple guys are doing projects you can get a better deal. My 2x.25" DOM is just over $10 a foot.
2. Red Rocks 4x4 is the best price (by far) I've found for JJ and a lot of fab parts. Off-road Overstock is another good source, as well as Rough Stuff Specialties. Also look in the Vendor section on Pirate.
3. http://www.aladdinsteel.com/ Aladdin Steel is a good place to look up steel to figure available sizes. If you're looking for 2+" DOM with and ID of 1.5" you can get several sizes. Also gives the weight per foot so you can figure out how much more unsprung weight you're adding.
4. Fastenall had the best prices on jam nuts and will usually have what you need in a couple of days.
Now on to some theory.
I believe a FS of 2 is plenty for the lower links. I'm running .25" wall 2" OD DOM and that's pretty good for a 3K# buggy.
Upper links will only see compression/extension forces on them so lighter is more than enough. 2" is overkill to a high degree. I'm using 1.375 x .188 wall tube.
It's nice to have left and right threaded joints at all the links so you can adjust them on the fly. Of course, then you should have jam nuts on all the studs.
If you want to use angled lower links you need to have a fixed bushing at one end, otherwise the link will rotate and give you a bunch of rear steer. Why angle the link you ask? For better ground clearance while getting the mounting point as low as possible on the axle tube (rear below).
Put a winch in back so you can pull the body down so the coilovers don't unload as the rear unweights on steep downhills. Do you need it? Maybe, maybe not, depends on how well the suspension actually works.
Unless $$ is really an object, and I know it can be, just go coilovers right off the bat. Or even air shox IF YOU ARE WILLING/ABLE TO WORK ON THEM TO GET IT RIGHT. You'll stand a much better chance of getting a coilover right than air shox and you'll need to reoil/recharge several times. If you do a cost comparison you'll find that $400 a corner for coilovers is reasonable vs. say a nice set of Deaver leaf springs ($450 or better by the time you get them home) and a set of good shocks ($375/pair for some Bilstein 7100s). Looks like $800ish to me and the ride won't be as good.
When you're running your measurements and making calculations, ensure you're making them the correct way. If the lower link is 40" long and at a 15 degree angle, it's placement on the X axis isn't 40", it's more like 38.5".
Build adjustment into the mounting points at each end of the upper links, that will allow you to change your anti-squat to dial it into what you want as you learn.
My definition of Anti-squat: the way the rear suspension will move as accelerative forces are placed upon it. So, a really low AS will cause the rear end to SINK upon acceleration and a high AS will make it rise. Front suspension will also play a part in this.
Gotta run,
Joe
thanks for the help.
(Oh yeah, I'm laughing right now.) There are some keys to saving D44 axles with big tires. Good axles, good ujoints, and don't apply a bunch of power when you have the wheels cut to the left or the right. Pretty much every axle I have broke on the front, and there have been more than a few, actually into the double didgits, has been at full lock. Oh yeah, I run 36" IROK's. I really would like a 9" D60 Hybrid.
But you don't just break D44 stuff, you spread the love throughout your Bronco. 
, not wheeling it.
)
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