Pros & Cons
Spring- Cheap and easy: Not as much travel, usually stiffer ride.
4Link- Better ride, articulation: More complicated to engineer, more money.
Just the basics. I'm sure somebody else will chime in with more details.
well i will chime in lol. ;D. it depends on what your setting it up for. and if its front or rear. for the rear i happen to like the 4 link but for the front i like 3 link. springs are nice if your on a budget. i have seen plenty of sprung trucks with tons of articulation do well in moab.
another bad problem about springs is that your approach and departure angles are less then a 4 link.
as said before though there is cons of 4 links. they are expensive(i have alot into my TJs 4/3 link set up. and alot of time. but you can make the truck to all kinds of random stuff with just the way you set the 4 links. I.E. the point of contact of the outside to inside for link compared to the center of the vehicle(if you take a couple pipes and use them to vusually extend the links and see where they would cross in reference to the center) if its aft of the center of your vehicle when you hit the gas ther rear end will drop down to add load to the rear. if its forward it will raise the rear end. if its dead center then it will stay level.
there is all kinds of random stuff you have to keep an eye on when building a 4 link set up. but if you do alot of crawling its definatly worth the time and money
how much lift are you going to run? big motor?(why should i ask, bob and brian both like big motors). wheel base, travel, $$ to spend. the ability to do the math for the design. now for my 2 cents. what i prefer and reason why when done right.
double triangleulate 4 link=has the best side to side control out of all 4 links. no side to side shifting though the range of travel. good articulation.
single triangleulated 4 link=good side to side control. good articulation.
parallel 3/4 link= needs a panhard bar, watts link, or a diagnal link for side to side control.good articulation. depending on which locating device you use the axle can walk from side to side when traveling up or down
wish bone 3 link= good side to side control. good articulation. one less joint than a 4 link.
radius arm/2link= needs a panhard bar, watts link, or a diagnal link for side to side control. so-so articulation. depending on which locating device you use the axle can walk from side to side when traveling up or down
springs=cheap, easy to use. depending on hieght you may need a panhard bar for side to side control. also may have to add a traction bar to control spring wrap.
over on pirate4x4 their is a 4link caculator that can help you figure out the angles you need. I'll look in the morning for my chassie design book so i can tell you the authers name and the correct title.
a couple of tips, keep the bars under 18 degrees and the front locating points between 65% to 80% of the ones on the axle. hope this helps.
oops i forgot what i prefer. i like triangulated 4links the best but i do build a lot of 2 links, do to them being simple and 8 to 12" of articulation(lift on one tire) is good enough for what we do. my truck i'm building is on radius arms.
i dont think that there will be a big differnce in weight with springs or bars. also you dont have to use dom tube, strucual(sp)tube will be fine.
Quote from: rebelryder on March 19, 2009, 12:18:05 PM
as said before though there is cons of 4 links. they are expensive(i have alot into my TJs 4/3 link set up. and alot of time. but you can make the truck to all kinds of random stuff with just the way you set the 4 links. I.E. the point of contact of the outside to inside for link compared to the center of the vehicle(if you take a couple pipes and use them to vusually extend the links and see where they would cross in reference to the center) if its aft of the center of your vehicle when you hit the gas ther rear end will drop down to add load to the rear. if its forward it will raise the rear end. if its dead center then it will stay level.
ok, i see a problem here. on my show car (rear axle, trianglated 4link) looking down from the top, my top angled bars meet at the back of the motor when a line is drawn from them. and when you look from the side the lines from the bars meet at 4" of the ground when its at a 6" ride hieght. no lines drawn from the bars conect behind the truck and it will squat the back end and it hooks up good. some times when i use the line lock to do burn outs, the front tires will slide across the pavement before the back tires will break free. i am talking about a couple of feet not an inch or two.