road race maverick.....

There's flex in your bushings and shackles and probably the springs themselves, especially when pushed hard

 

Wardf,

I guess it really depends on what you want to do with the car, if you want to go out and carve corners, race on a track, or something like the Silver States Classic vs. just wanting to drive it on the street 99% of the time and the rest will be racing............................it also makes a big difference in how much $$$$$$ you want to spend. So to answer your question, sure can run a triangulated/and or unequal 4link without running a panhard bar or watts linkage.
Lets talk rear suspension systems.........they can be as tricky or as simple as you want them to be, but remember......."the devil is in the details".

.The roll center of any solid axle suspension depends upon what is controlling the lateral movement of the axle assembly, or actually preventing it (lateral being side to side). It is a pretty hard thing to describe, but it depends entirely upon the given geometry of a particular system/car. They all work differently, but let's tackle a couple of systems.

A parallel four link (or three link, or torque arm setup with parallel links for that matter) depends "entirely" upon the Panhard Bar, or Watt's linkage to resist axle movement in the lateral direction, i.e. under cornering forces. IN this case, the roll center is defined by the intersection of the PHB height (keeping things as simple as possible) with the centerline of the axle, and again, to make things simple, let's assume that the links are parallel in top (plan) view. The roll center is an imaginary point in space that the car will roll about, specifically, the sprung mass of the car, under a given lateral acceleration (cornering force), and it is a very important attribute for certain. More important than where it "is" in a static case (not moving, just sittin' on the curb), at least in my opinion is what it does dynamically. PHB's do a really nice job at controlling the roll center in a dynamic sense, the other "better" solution is a frame mounted Watt's linkage.

A converging four link does things a bit differently. In this case, the angled arms (usually on the top, as in GM A body, late Mustang, plenty of aftermarket setups), not only control the pinion angle, but they are also responsible for controlling lateral axle movement. To find the roll center of these setups, you need to look at the convergence angle and intersection, and frankly, without a picture, it is really hard to describe. In the case of the GM A body, and also the Mustang (and the derivitives of these in the aftermarket), they suffer from a really high static roll center, and worse, the roll center moves all over the place. Not only that, but think about it, the upper arms are asked to do two different things at the same time. I am personally not too good at multi-tasking, and these setups aren't in usual practice either. If you have ever driven a later Mustang in anger, there is no question that the back end of the car has come around on you in an abrupt fashion, known as snap oversteer. This occurs when (and because) the upper arms fully compress their suspension bushings, and the system becomes rigid (a trait of ALL four link systems in roll, by the way), and not at the time you'd like.

The Satchell setup is essentially a GM A-Body turned upside down, and it can be made to work pretty darned good. The engineer that designed it is named Terry "Satchell." It's far better than the other type, because the roll center height is a lot lower, but frankly, it suffers the same binding issues as the other four link systems. It's a bear to package too, the long upper links need to go somewhere, and that means no back seat.

So what do you do? For a street car? Whatever you want, and just do a good job tuning it. They will all work pretty good if you aren't nutso about the last ounce of performance. What's the ultimate solution? There isn't one, it ALL depends upon what you want in terms of packaging, performance, cost, ease of install, tune-ability, appearance, etc.

Mav1970,
Leaf springs are not a self centering device in any since of the word. The bushings flex (unless you have solid steel or aluminum type) and the springs flex side to side (unless you weld them solid to each other), so with a leaf spring you need something else to accurately center the rearend. Now, for street performance you may choose not to run one, but if you are out carving corners I can guarrantee you will need one.
The corner to corner bar in a triangulated 4 link is only used in drag racing..................it doesn't work with corner carving with a triangulated 4 link.

Has anyone thought about a T/A type set up? I know the owner of
http://www.hotrodstohell.net/ and he has had a few cars with his rear suspension that were very competitive in the unlimited class of the Silver States Classic race...................these are the guys that reach speeds of 200+ on that 14 mile straightawy..............I have gone for a ride in one of his cars and they certainly do perform and hook.

 

I almost forgot................Streamliner......................I Absolutly Love Your Car!!!!!!!!!!!
If you ever venture out to the West Coast bring the car and we will take around one of the tracks here in NorCal, Laguna Seca, Sears Point, or even Thunderhill. I think Laguna Seca would be perfect, or how about entering it in the Historics at Laguna Seca................you would love the track..........it is one of my alltime favorites, although Thunderhill is pretty good and very forgiving track if you do go "off track"............if you know what I mean.

 

Thanks....I once was given a ride around Sears Point by Steve Saleen in one of his Mustangs, that was before the track was changed....Would love to try Laguna for the corkscrew....Used to run Pocono {i think there are about 4 different road course configurations there}, Limerock {short, but a beautiful area} Watkins Glen long course {fast, but it sometimes snows in mid May, and Bridgehampton before it closed, which was never updated since it opened but was my home track and extremely challenging {once took down a tree there on cold tires}...Aaahh, the good ole days

 

Very well explained olerodder. I guess I was trying to keep it even more simplier than you were LOL!

The half a dozen or so leaf spring stock cars, I was involved with over the years, you couldn't add a Watts system to them so I have no practical experience with using one with leaf springs for racing. I was thinking of basic street use where you need nothing else added to locate the rear side to side.

My coil spring stock cars had a simple 3 link setup with a panhard bar but, no matter how long I made my panhard bar, I always had to deal with some rear steer caused by the arc of the bar. The Watts system eliminated the rear steer problem and made the car very stable in the turns (all left turns). I have seen, on some of the competitor's cars, the crew trying to use multiple lateral locating devices or adding a panhard bar to a setup that already was being located by it's own design causing binding so I always tried to keep it simple.

 

Streamliner,

Yes, the good Ole Days...............I still have my SCCA license and try to keep it up each year but it is getting harder and harder as you need to attend a minimum of 2 National events. I race a Spec Miata and when there are 30+ other Miata's out there it gets a little dicey. I did race one of Stacey March's GT350 Mustang in a Historic at Laguna Seca, and have raced the Miata there also...............a real kick in the pants...........yes the corkscrew is about the most fun you can have with your pants on..............have also raced at Infineon (Sears Point) and Thunderhill which is the track that the San Francisco SCCA owns and runs..................it is a 15 turn (old track) with some nice elevation changes and very forgiving if you go "off course" because it has a lot of flat land and only a few K rails...........so if you go off you don't tear up the car too bad. I actually got to drive one of the Flying Lizards GT Porsche's at Thunderhill...............there is a big difference from driving into turn #1 in a momentum car like the Miata at 100mph and the GT at 140mph..................WOW, what a rush!!!!
Here is a picture of me in the Miata when I got my license and the Flying Lizards GT with me between turn 13 and 14 approaching the bridge.
http://thunderhill.com/staticpages/index.php?page=TrackMap
I've had a lot of fun in the SCCA, being a licensed Tech Inspector, Sound Technician, and a Member of the Course Crew.............Ah Yes, those Good Ole Days.

 

Bob,

Sorry, I meant to reply to your post but got caught up in ole memories.
Well, I've done a lot of racing in my life............but by no means as much as some other people, and I am always open to ideas................but with that said I know what has worked for me from practical experience both on and off the track..................although I ahve never done any circle track racing but it is on my "Bucket List", as I'd like to slid a 700hp car around a turn or two in the dirt..................just to feel what it's like!
I have owned a lot of leaf spring cars and always tried to improve the handling............and just my own personal feeling is that even if a car is just driven on the street it can always be improved in the handling department, you never know when you may have to make a drastic/sudden change in direction to avoid something or keep yourself out of harms way..........and improved suspension will do that for you, even if it is just putting an adjustable sway bar in the rear..................plus I think it is a lot of fun to work on the suspension aspect of a car..................IMHO

Here is an interesting article I happened to find, and realizing it is for a truck, but still holds true with a car;

http://www.timskelton.com/lightning/race_prep/suspension/panhard.htm

 

I'll look at the link when I get home as my work place filters won't let me open it. My racing was done from 1980 through 2004 on the same 1/3 mile paved oval in northeast PA. once promoted by the Jimmy Spencer family. We were just a bunch of guys that didn't know much about racing in circles but still were able to win the 81 championship along with 8 feature wins. That initial team faded away but I continued working with different teams until I was asked to build a driver a car in 92 and took a stab at car building. No matter how successful we thought we were, I always felt there was room to improve. Through the years, I tried things that flat out didn't work but in the process found a lot of things that did work. Around 2001 a 14 year old kid came down from New England and was setting track records in a pavement Late Model. I started snooping around and noticed that the big difference in his car from the others was a Watts Link setup. That sold me and a similer setup went into my car shortly after that. The driver who had been racing for 20 years or so told me that it was the most stable car he ever drove. I can't wait to see for myself what it does in my Maverick.