Your first picture is almost exactly what I have under my car. I have a spring-over, with short 4-bar and a large kick up in the frame. My car rides good (rough - like an A should). There isn't much movement back there and very little weight over the rear end. I haven't had any issues with binding u-joints. I've been running it for 5 years, and have done some long hauls in it. Mine is all tucked up under the car though and the trad police need to get on thier knees to see them (and they're chrome too!). But I don't have to worry 'cause most of them can't get back up without help anyways... zing! It's a decent way to go with a large kick-up in the rear 'cause you will find that the long trailing arm style suspension will interfere with your floor. You could move that lower link mount up a little so you can't see it. Is your car channeled?
Need Louvers ?, The photos I posted don't show the torque arm, but they both have them later on in the build.
IMO, this is your absolute best choice. Simple, works with ANY width rails, and it's pretty drama free. Fogger's last post on that triangulated thread contained the MOST critical piece of information: "PROPERLY DESIGNED". He went through the entire range of motion and found the link locations that would keep the tri-4 link out of a bind. You keep saying you're in over your head, etc. I wouldn't even attempt a tri-4 if that's how you're feeling....
I'm definitely starting to lean that way. Do you have a side shot of the connection on top of the pumpkin? How does the arc of the third point work with the torque bats being so short. Can I use just the spring and torque bars?
Your biggest problem is the unequal length of your bars. Go to equal length bars and move them inward and make your front mounting bracket on the inside of your frame. With a true equal length 4 bar your pinion angle will not change. I'm running a similiar set up with 8 inch Sprint Car bars at about 11 inches from mount hole to mount hole.
That's the direction I went in after looking at a couple of elpolacko's builds. Seems like the best choice. Posted from the TJJ App for iPhone & iPad
With that Ford housing you have, I'd just weld plates top and bottom and use clevises threaded into the ends of the arm. Kinda like attaching a batwing to hairpins, but with 1/2" bolts. The arm can be round or square tube, or a formed "C" channel for an old school look. I used to wrench on a 1916 National vintage race car that had a torque arm as built, so it's not exactly "late model" technology...
I'm sure some of you are banging your head against the wall with my questions... but - If I have a properly set up transverse spring and bottom mounted torque bars on each side, do I need anything else? A top bar?
YOU'VE DONE the hard PART WITH YOUR SCALED DRAWING!! When I worked for Ridewell and also Reyco as a suspension engineer we drew out the suspensions just like you did. We did not use Autocad back then! !960's. We used 1" = 12" scale. Make yourself an exact cardboard model and walk it thru the movements to check your pinion angle!!!! Pin it at your joint centerlines. You should use 2" of rise and 2" of drop travel (called Jounce). The shorter the rods the more twist you will have from side to side deflection. Probably no more than 1 degree minus at static stand-still for pinion angle with those short bars. All of this should be figured loaded and wet including the driver. (Use lead or shot bags in the seat and trunk for gas. Figure roughly 7.8 # for fuel per gallon. Be sure to check pinion alignment from side to side also!!! Be sure to keep equal angles at both ends. The real question here is to follow each arc and see if there is any binding. The traverse spring depending on where you anchor it in the middle will determine the amount of flex. also the number of leaves. I had this same setup that you are doing on my 34 coupe (see my album for one shot of this car,) It handled well in nostalgia drags at Desoto dragway several years winning. Only my bars were longer somewhat. 22" and 24.5". the unequal lengths ARE IMPORTANT! They will change the pinion angle if you are not careful you could have problems. Run thru the geometry with your scaled model. You are on the right track. When we built cars we often will have others tell us "That will never work!". Sometimes they are right. A lot of times we are in the winners circle winking at each other! Good luck (engineering!). P.S. All of this changes if you plan to road race this car! Also any gymkhana driving! This will be of use in drag racing and street driving but not on California's curvy mountain roads.
Wes (ElHueso on the HAMB) is modifying the ladder bars he built for my modified like this, right now. I had a clearance problem with the spring since its in front of the rear end. I'm hoping this, plus changing to a standard eye spring will resolve it.
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