That's funny , Warren I was just reading the online catalog from them. Lots of cool stuff. Are four links hard to figure out, when you have never done one?

It would be easier to answer if you included what vehicle you intend to install one in and what that vehicle will be used for.

then you will have to run a panhard bar unless you go with a triangulated system.

What body style? What drive train? Full fender, hiboy or channelled? What suspension is he running? Coils? Transverse? Why not run radius rods, they are so much cleaner on a rod? Look at Speedway, they have all kinds of rear four bar or radius rod setups.

Warren

Thanks guys, I will have to get together with my friend and get some answers.

Mr Samis wrote:

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I'm helping a buddy put it in his hot rod . He has a 32 ford cab that he is fabricating and not quite sure if it is going on a built frame or an s10 frame. Will be just a driver not a racer. So I was thinking just a parallel 4 link would be ok. Am I wrong to think this?

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"32 Cab" suggests a pick-up truck cab.  If he runs an S10 frame (which is admittedly, not a popular choice of chassis for a '32 Ford), I'd just stick with the S10 parallel leaf suspension it already has.  Not sure how good a job '32 fenders will do of hiding the front suspension from view (if that's his intention), or how "acceptable to the masses" an S10 suspension will look without fenders, on a '32 Ford though .... IF that even matters to the builder/owner (which it really shouldn't, although it will definitely be reflected in the resale value, if and when the time comes to sell it).

 

-- Edited by pint and a pound on Monday 23rd of March 2015 01:14:26 PM

I have never heard of Fox Mustang guys removing the factory link suspension and replacing them with half leaf springs while "springing" the car with either the factory coil springs or coil-over shocks.

Suspending a vehicle with either coil springs and shocks or coil-over shocks (and a pan hard bar) while using partial leaf springs in place of ladder bars or a four link, or wishbones, or a "truck arm" suspension does not make any sense to me either. Can it be done? Sure, it "can" be done. Does it make any sense? Definitely not to me.

I can honestly say I have never seen this done on any car ... ever ... rod, racer, anything.

A quarter elliptic spring set up will work as long as there are separate, extra links that prevent axle rotation, but that is definitely not what you are describing.

Not the end of the world here .... just two differing opinions  

 

Cheers

A parallel four bar system is the easiest to install. Just buy the brackets and make the bars. For the street run a panhard or watts link. Wishbones are nosy and diagonal links break too easily compared to the panhard or watts.

You can also do a triangulated 4 link but you have to make sure the arc of movement for all the links is the same or you will have binding. Or you can do what the factories do and use large soft bushings that deflect to allow the different arcs of motion.

A quarter eliptical spring setup with coil overs is just a bad idea. Don't do it. Too many places that flex. Replace the quarter eliptic springs with ladder bars if you are going to do that. I don't really like ladder bars on the street, but they work.

Maybe this would help to clear things up a bit: FOX BODIED MUSTANGS ARE FROM 1979 TO 1993 and had a factory 4 link set up and wouldn't use the Cal Tracs system or leaf springs.

Dick Kirkpatrick wrote:

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I would do a triangulated four link (all bars adjustable) and make the yoke of the triangulated link free to move in and out of a receiver yoke. Keep the yoke lubricated.

-- Edited by Dick Kirkpatrick on Wednesday 25th of March 2015 04:57:27 PM

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This will not work.  You would have no control over pinion angle.

The triangulation of the triangulated links would basically put them into a bind if you use standard rod ends or bushings.  You would need to use spherical rod ends, and you would be relying on the rod ends ability to pivot to able to move the upper bars.  Now you have two different problems - side loading the spherical rod ends (they don't last long doing that) and the fact that the upper bars can change in length, giving you zero control of the pinion angle.

The only way to make this work is the fix the rear of the bar to the axle so that the axle cannot rotate.   Now you basically have a ladder bar with a poorly designed wishbone.

 

I have installed ladder bars in a few fox mustangs, both were tubbed track cars so they just had a diagonal locator.  Used coil overs and Chris Alston bars.  

 

 

-- Edited by RacerRick on Monday 6th of April 2015 04:42:56 PM

Daimler sp dart 250s had a half sprung with shocks & centre point a frame same as d type race jag,s, was that good they cleaned up at le man for years. depends what way u set it up

Dick Kirkpatrick wrote:

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I would do a triangulated four link (all bars adjustable) and make the yoke of the triangulated link free to move in and out of a receiver yoke. Keep the yoke lubricated.  

I should make myself clearer on this. The triangular bar is an axle locater. The rest of the setup is a normal adjustable 4 link.

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A true "triangulated" four link does not need any kind of "axle locator" bar (above and beyond the two upper and two lower links) due to it's design as the angled bars prevent the rear from moving side-to-side (many GM vehicles used this very suspension).

It sounds to me like you (D. Kirkpatrick) are describing a drag specific four link suspension (where all four bars are parallel with the center line of the chassis) that is also equipped with a wishbone locator to prevent the rear end from moving side-to-side.

 

Yellow frame/suspension shows a triangulated "street" four link .... bare metal frame shows a typical "drag car" all-four-bars-parallel-to-the-center-line-of-the-chassis, fully adjustable four link suspension PLUS a "wishbone locator" where the "wishbone is attached to the top of the rear end housing at one point, and attaches to the horizontal cross member, above the drive shaft loop at two points.  I have also included a pic of a wishbone locator on its own ... you can see where one tube fits inside a slightly larger tube (this is the slip joint) where the two "bones" meet to form the "wishbone", allowing forwards-backwards movement or the rear end during suspension travel (due to the rear end travelling in a slight arc), while eliminating side-to-side movement. 

 

 

 

 

       

 

      

 

 

 

 

 

 

 

-- Edited by pint and a pound on Friday 10th of April 2015 05:06:31 PM

Pint and a pound: Exactly what I was referring to except the 4 bars are not parallel.

Thank you, good pictures.

Here is a pic I have copy/pasted directly from FJ Smiths site. The item pictured is a Grand Am Rear Sub-assembly.

This assembly uses a four link suspension, with a wishbone locator (you can see the wishbone in the pic). You can't see the actual four link bars as they are mostly hidden by the frame rails. However, all four of the bars run parallel to the center line of the chassis, neither the upper or the lower bars are installed at an angle (when viewed from the top) like a GM inspired "triangulated" four bar (refer back to the yellow frame in my earlier post).

Here is the text taken from FJ's site in regards to this photo:

Custom designed rear sub-assembly kits include:   

• rear frame section sub-assembly of 2" x 3" x .083" tubing with full crossmember    
   •rear frame rails    
   •full width dropped crossmember with brackets and tubing    
  Smith Performance Specialties 4-link rear suspension complete with:    
   •laser cut º” brackets    
   •seamless links are 1º" x 095" chrome moly "Pro Stock" style links with left and right hand adjustments 
   •precision fit teflon lined rod ends    
   •wishbone track locator    
   •all hardware, plated Grade 8 or precision AN with nylock nuts
• •specify equal or unequal length 4-link

Ok, I understand now Dick Kirkpatrick. You are describing a parallel four link with a wishbone track locator. They are usually setup with the bottom bars parallel to the ground, and generally the upper bars are used to adjust your instant center. That is standard drag race stuff and I have had a couple of cars setup like that.

How the industry describes these suspensions is like this:

A parallel four link means that the axle locators are parallel to the frame rails. All four links of this design need some sort of device to control side to side movement - like a diagonal bar, watts link, panhard, or wishbone.

A triangulated four link, means that one pair of bars (usually the uppers) is canted in or out (usually in) to control side to side movement without the need for another link.