Thread: Parallel or triangulated 4 bar, which is best?

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Originally Posted by Dave Severson

Most welcome Mike. Someplace in my gallery here on CHR there's some pics of a triangulated 4 bar with a bunch of adjustment holes I'm fabbing up for my 'maro.... the geometry works great on paper,,,,but unfortunately the car is now on my round-to-it list and I can't tell you how well it works.....

you used paper yep i laid mine out on the shop floor, were i am at now is low and just back of the oil pan crank center line were they intersect like you said i only have some holes lower front two hole lower back bar 5 or so and upper top front one and 5 on the upper back on the rear end never move it no need to

Originally Posted by pat mccarthy

you used paper yep i laid mine out on the shop floor, were i am at now is low and just back of the oil pan crank center line were they intersect like you said i only have some holes lower front two hole lower back bar 5 or so and upper top front one and 5 on the upper back on the rear end never move it no need to

Main reason I made all the adjustment holes was cuz I put a bunch of engine setback in the car and want to be able to play with the handling a bit on the road course down by Omaha....and maybe the road around the lake!!!!!

dave when you say track bar ? better the a pan hardbar ? your talking a track bar .@ bar crossing the lower two bars working the lower bars mount point s at a cross angle holding the rearend in track with frame off the lower front point of bar and crossing the back rear end mounting point from the other lower bar at lowest point to hold track ? .pan bar many push the rear end abit but if angle is right not much . but with the track bar you see load and unload work thru the rear end at lowest point. l had both with tub out car so the track bar may work better with a car not tub . yes a watts is the best but shuffing that under a car your going to look like a jungle jim set. just my two bits worth i know nothing

I run a parallel 4 link with a track bar in my Model A. The track bar is mounted to the left lower fwd 4 bar mount on the chassis and traverses over to the right lower aft 4 bar mount on the rearend housing. With this type setup there shouldn't be any lateral (side to side, left to right) movement of the rearend in relation to the chassis. The position of the lower 4 bars to track bar, makes 2 triangles that are parallel to each other. One is supported through the rearend housing, the other through the chassis itself. Since all the 4 bar mounts are fixed and parallel to each other, there should be no lateral travel between the chassis and rearend even while the rearend is moving up and down through is arc. I don't believe there is any loading and unloading work through the rearend as stated earlier. I can remove the my coilovers and move the rearend up and down to the extremes with no binding/loading at all. If there was any lateral movement, it would have to come from the 4 bar mounting plates that are welded to the chassis, flexing. Possible but not likely. In my opinion this is a better setup vs. a panhard bar. The only drawback is space, and while doing gear changes.
I have encountered the death wobble twice. The main reason for me was I was trying to run the lightest coilover spring rate possible, and run the least amount of rebound possible. The fix was either more spring rate or in my case I dialed in more rebound. Problem solved.
As far as Triangulated vs. Parallel, the OEM's have used the triangulated for eons for a reason, they are fairly easy to install with the space constraints considered. No panhard bar or track bar to deal with. It's built into the geometry of the triangulated mounting system. In a hot rod I don't think you can go wrong either way.
I chose parallel 4 link with a track bar because it fit the build of the car!

Keith

Reason I prefer the track bar is that it moves at the same rate and in the same arc of travel as the lower bars... Things do move around down there a lot when you drop the hammer with some sticky tires or slicks. As 31 mentioned, the track bar forms 2 triangles which are the strongest support of any geometric shape, and whatever deflection there is in the ends or the tubes themselves (yes, they do deflect under load) the movement is in the same direction of travel and arc on the lower bars and track bar with all the torque being applied to the forward mount points of the lower bars. A panhard bar actually transfers torque to the frame rail where the end is mounted. Probably more of an issue with us gear bangers then with the automatics, and not really an issue on the street cuz if you have enough horsepower to make deflection an issue on the street it will just blow the back tires off anyway......

well i will beat the dead horse on this .then i will be done. track bar can flex most of the pro street kit use a 1/2 bar that is to small for the street i feel you try to stop side to sid movment thru the lower bar to one point at the lowest point on the other side lower point. there is a better way ???yep. i do not car if it is triangulated .this is at the back end so by the time your at the front wheels the car will track washy and loose i built car s with them for racing only drag cars .but for the street i look at a bar independent of any lower mounting points that is hook to the frame higher up . closer to the mid point of the frame .center to were most of the weight and force is .a bar seeing the load strait on mounted points on the same plane as the axel side to side is the rear end is loaded guys like track rods there EZ to put in .but you will never see one in a car that runs around corners for a living panbar may jack the rear end some but your grabing the frame more to the center of whats going on? so then there a watts the best way to go if you can get it in there ok now i am done beating the horse .. good day

Originally Posted by Dave Severson

Reason I prefer the track bar is that it moves at the same rate and in the same arc of travel as the lower bars... Things do move around down there a lot when you drop the hammer with some sticky tires or slicks. As 31 mentioned, the track bar forms 2 triangles which are the strongest support of any geometric shape, and whatever deflection there is in the ends or the tubes themselves (yes, they do deflect under load) the movement is in the same direction of travel and arc on the lower bars and track bar with all the torque being applied to the forward mount points of the lower bars. A panhard bar actually transfers torque to the frame rail where the end is mounted. Probably more of an issue with us gear bangers then with the automatics, and not really an issue on the street cuz if you have enough horsepower to make deflection an issue on the street it will just blow the back tires off anyway......

..YEP ... i thinking we maybe drive are stuff harder on the street then some do dave

Yuppers, Watt's link will always be the best and for me the preferred....Even though sometimes getting all those pieces in place above and behind the rear differential is kind of like putting a jig saw puzzle together and you get to make all the puzzle pieces!!!!---which I think is the good news!!!!!!!

PS--Dead horse thoroughly flogged and laid to rest......

I wish I could of run a Watt's Link, no room for me.
Those Model A's are like packing 10 lbs of crap in a 2 lb sack!
Keith

Originally Posted by blwn31

I wish I could of run a Watt's Link, no room for me.
Those Model A's are like packing 10 lbs of crap in a 2 lb sack!
Keith

Yep - I know all about filling blivits:

http://i70.photobucket.com/albums/i8...finalasm12.jpg

I had a three link in my Monza---absolutely no bind anywhere from 3 points and used a y link from lower frame to a slider point under center of pumpkin arae