4 link / ladder bar not for street handling?
 

I am getting more confused on the rear suspension setups

I keep hearing how ladder bars and 4 links bind and dont handle, etc...

How about ladder bar kits that come with bushings, for example, this place:

http://autoweldchassis.com/lb.ivnu


And exactly what kind of binding are we talking about? I want my car to hoook straight but also go around corners and ride normally

ANd what about 3 links? I dont hear much about them nor do i see too many kits for sale.


The autoweldchassis has a ladder bar kit for the street with bushings, the complete bar, panhard, coilovers, mounting bars for like $650, not too shabby

Ladder bars have as much place on a street car as do welded spider gears...no place at all.

The reason you don't see many 3-link kits is that building a 3-link in "kit" form is fairly difficult to do. If you happened to have an early "F" body I think somebody will chime in soon to help you out with that.

its for a 68 roadrunner

I would just do the leaf relocator and some shocks to fit my 18x10s but i thought i would do something a bit more interesting back there


So even ladder bars with urathane bushings on all ends still wont work well on the street?

Ladder bars in any configuration are the absolute worst possible design for a street car. The effectively lock the rear axle, you might as well run a straight axle in the front as well.

What he said.. ladder bars are not four links and are more of a pro-street/drag race deal.

Also, there are many different types of 4-links, some are better for handling and some are better for drag racing.

I'm not a Mopar "in the know" guy so I am not sure what is available for your car, but I will tell you it is imperative that you heavily research your options before you pull the trigger or you could end up with a car that does not do what you want it to.

Agreed,ladder bars are not a great idea on the street and they`re especially bad if you want the car to handle. Think of them as a huge hinge,pivoting on the front heims or bushings. The rear axle can ONLY move straight up and down. It can`t twist side to side to follow the road or allow for any body lean so the car ends up skittering through the turns like a big shopping cart. Not fun (unless you`re a kid with an actual shopping cart then it`s BIG FUN! :rofl: ).
4 link can work very well though. Most factory 4 links use converging arms with much shorter than optimum upper arms and do indeed have some inherent problems. But if you start with a good adj. aftermarket 4 link you can make it work for you. The main thing is to forget about using the diag. track bar or stubby panhard bar they include with most kits and install a nice long panhard bar roughly the same height as the axle tube centerline (for starters) and perfectly level at ride height. Might as well make the mounts adjustable so you can keep it level even if you change the ride height and so you can raise or lower the rear roll center as a tuning aid.

There are two issues with regard to drag race style four link and ladder bar systems that make them highly undesireable for street applications. As Marcus pointed out, a suitable lateral locating device such as a long Panhard bar is a must for the street, the drag race kits typically come with a "diagonal" link, useless for controlling side to side motion of the car reliably, and frankly, dangerous as a result. A good friend of mine recently bought a four link 57 Chevy with a diagonal bar, he got "concerned" when he could hear rubbing of the rear tires, and could get a whif of rubber. The rubber turned out to be two things, tires, and far worse, rubbing on the fuel line. Swapping a simple Panhard rod completely transformed the car, and made it remotely livable on the street.

The other issue is that the drag race setups use spherical rod ends for the pivot points. While it is obvious that the ladder bar setup has serious bind issues in roll situations (i.e. any cornering), the same condition exists for the four link setups using rod ends also. The only reason that either of them roll at all is because something in the system is bending, stretching, etc. BOTH are overconstrained in roll, period. I think the reason that folks think the four link systems don't bind is that there is actually more stuff to bend, so the bind is less obvious. Further, using some form of compliant bushing in a four link (rubber, poly, etc) will free things up a bit and allow the setup to roll more, until of course the bushings are fully compressed.

A three link has the advantage of being completely free in roll-bind situations, by design. Each of the links only has one job to do, the redundancy of the two upper links is eliminated by removing one of them. Three link setups also require a Panhard bar or other lateral locating device, such as a Watt's linkage. You will be seeing a good number of three link applications on the market very soon.

Mark

Edit: Spelling

With all of that said I would recommend sticking with your leaf springs. If this is a street/sometimes(maybe) track car there is nothing out there that will outperform the leafs on the street AND give a decent showing on the track with some tuning.
I was doing the same dance you are when I was bubbling up my Astro van project. I talked to a LOT of people before I decided to stay with leaf springs. The ONLY thing leaf springs have going against them is; they are not high tech. Mundane and Simple work very well though and there is a lot to be said for simple. Like "cheap", "no maintanence", "easy to tune" and "not a major tearup to install". Unless of course there is some narrowing involved...
Mark

looks like im going with mopar SS leafs(much thicker and stiffer) which I heard should prevent axle wrap(since i dont want to do traction bars) but i heard they are stiff, unless there is anything i can do to prevent wheel hop and axle wrap with stock rate leafs

Im gonna use the mopar relocation kit(which is kinda old school and ghetto, but works and moves springs in 3-4") and just get some koni shocks i think

For hte front im gonna go with a 1.12" torsion bar, koni shocks, full rebuild kit and upper control arm.

Subframe connectors and a 8 point roll cage will finish it out.

18x10" mustang bullitt wheels(since they fit) on 295/35/18 drag radials
18x9" front with 255/40/18 tires

We'll see how it turns out, i want a low, mean, pro touring look and a car that at least handles decently(its a long, boat so i can only get so much)

this is the look its going for(same wheels, different color)

http://i21.photobucket.com/albums/b2.../choppedrr.jpg

Car is gonna be either black, or silver with those wheels but in black/polished lip