Frame design advice needed...

I recently bought this project '30 sedan and really am having a problem with the way the guy mounted the 4 bar link on the top of the frame right where the seat mounts will likely be. Most I have seen have been angled in and hooked to crossmember. This will be my first frame and I need advise / pictures on how I can change this and take it under the future floor of the car.

 

You could easily change it to a triangulated 4 bar if thats what you want to keep ?

 

If you plan to run your sedan "high" and have room for a triangulated "wishbone" type linkage that would handle well, ride nicely and not bind, especially if you have room for a spherical joint in at the center. But most rodders want a lower profile.

 

Not at all.

 

Tie the two bars together to make a ladder bar that has just the one mount down beside the frame. It looks like they will be fairly short, but with the limited rear suspension travel, you shouldn't have to worry about pinion angle change.

 

pull off those top bars, make a few brackets and triangulate the top bars. you might find a way to cut the top portion of the parallel four bar bracket off the axle to make it look better and get a couple of your triangulated brackets at the same time. i have some pics in my 28 rpu album of mine (same big Z). good luck.

 

Last evening a fellow had complaints of body roll and poor handling, w/the same panhard rear bar you have. The triangulated method may work out far better.
http://www.jalopyjournal.com/forum/showthread.php?t=517211

 

thanks guys!

 

Cut off the top bar brackets and use those bars to triangulate the top.

Should not be a huge problem to do.

 

The answer is easy when I studied the L/H side of the photo

"Geometry is Geometry" and "Parallel is Parallel" no matter where it's placed They should still be Parallel

Lower the upper links down so the front mount is bolted to the outside of the chassis rail [ below the top edge of the chassis rail ]
Lower the bottom link down so the front mount is slightly below the chassis rail [ weld some brackets ]
Make up some brackets off the diff to lower the mounting points of both the upper and lower links [ keeping them parrallel with the front ]

Get rid of that short panhard bar ,and go as long as practically possible [ to reduce the Arc in movement ]
The panhard bar should be horizontal at ride height [ with driver weight incl ]

 

Watt's link is better than a Panhard. It would install behind the rear.
You said it all, Tman. I'm about sick of these scrappers...

 

thanks guys! again... without totally showing my stupidity, if anybody has any picture examples they could post I would GREATLY appreciate it...

 

Heres a triangulated 4 bar, works well.

 

great example, Langy.

 

Thanks, You could also junk what you have and use a pair of ladder bars and a panhard rod but keep the panhard as long as possible.
ladder bars should be as close together as possible at the front.

 

If you plan to keep the sort of ride height that is indicated by the frame as it is, you'll have a hard job hiding anything inside the frame. I've used a really short four bar before, with the axle mounts behind the axle, to keep them as long as possible. Typically most hot rods have but a couple of inches axle movement, so you can get away with having the bars 18" long, or less.

The pickup I am putting together now has a triangulated four bar, shown here with gash square tube for temporary links, but I don't think you have the room for it.



My last car had the four bar very short, due to seat location, but it rode okay. See how the rear end of the bars are mounted behind the axle:

 

i am getting ideas now... thanks for all the advice and pics... all great work... thanks guys

 

more pics please

 

sorry this is about the only pic i have that shows the rear triangulated 4 bar.