Tech Week !!! Hot Rod Suspension Simplified!

[flatheadpete]

So basic yet it works everytime! Thanks.

[Rich Wright]

Beautiful, Sam...

[pasadenahotrod]

Great post, well illustrated and explained BUT I believe you left out one important measurement.
At least 1" should be added to the dimension for eye to eye measurement for the rear spring mounts, or front spring mount as well, to spread the spring and put the spring under tension as Ford designed it to avoid having to install a Panhard bar to limit sway. You probably did this but just left it out in error.
Using your dimensions would mount the spring like the stock 42-48 Ford design to make a softer ride which do NOT have the spring installed under tension when mounted so Panhard bars are required front and rear.

[COOTER]

Exactly what I had planned on for my A build. Now I could use this for reference. Great tech! Thanks.

[3wLarry]

cool thread...

[Southfork]

Yes, Henry did have it right. He used those wishbones for about 40 years!
Thanks for the reminder as to why he did that.

[SamIyam]

Originally Posted by pasadenahotrod

Great post, well illustrated and explained BUT I believe you left out one important measurement.
At least 1" should be added to the dimension for eye to eye measurement for the rear spring mounts, or front spring mount as well, to spread the spring and put the spring under tension as Ford designed it to avoid having to install a Panhard bar to limit sway. You probably did this but just left it out in error.
Using your dimensions would mount the spring like the stock 42-48 Ford design to make a softer ride which do NOT have the spring installed under tension when mounted so Panhard bars are required front and rear.

I probably need to clarify what I was saying... because when it's all said and done, I think we'll be on the same page.


I used a '40 Ford spring... and used the '40 Ford rear end that the spring came off of to get my measurements from "eye to eye" on the rear end.

When the body is off of the chassis, and all of the springs are in the spring pack, the spring is definately under tension, in fact... it's under the same tension as it was stock, because the mounting points on the rear end for the shackles, are the same.

If you use the stock measurements, especially on a light car, there is no need for a panhard bar.

I removed a couple of springs to make it right... as the stock '40 spring pack is a bit stiff for a Model A.

The real test will come when I get my first drive.



Sam

[Beau]

EXACTLY what I'm working on building now. The other threads on here have sparse info. This is a WINNER IMO.

Great job!

[39cent]

I did this baknthday but welded some metal along the top and bottom of the rear wishbones, to add strength for open drive. Fords wishbone setups were used on many 200 mph lakes cars.

[Max Gearhead]

Excellent thread!

[40FordGuy]

Nice !!!!!!!!!!!!!!!

4ttruk

[barrnone50]

Real super clean Fab job..Great Tech very informative and helpful for future builds for my next ride. Is the frame your handy work also?

[Cali4niaCruiser]

You get my vote so far!

[striper]

Originally Posted by SamIyam

One thing I wish I had known before I did mine was the affordability and availability of these. Would have save me cutting the ball cup out of an otherwise perfect '48 frame.

[SamIyam]

Originally Posted by barrnone50

Real super clean Fab job..Great Tech very informative and helpful for future builds for my next ride. Is the frame your handy work also?

The frame is actually a new raised and narrowed perimeter frame from these guys:

http://www.classicstreetrodmfg.com/model_a.html

I called them up and had them deliver it to the Turlock Swap Meet in January of 2011.

The basic frame was $700...


I should also bring up the idea of a "Torque Arm".

A good friend of mine is using this system in the rear of a roadster. He wanted a little extra insurance... and added a torque arm from the top of the rear end to the yoke.

I personally do not think it is needed... especially if you gusset all of your joints.

If you think about it... it is common practice to run wishbones, albeit split, on the front of our hot rods.

Cars stop much faster than they accelerate. So, the forces exerted on the front wishbones are greater than can be exerted on the rear 'bones.

In addition, with tires that spin... the force is even less on the rear 'bones.

I have a theory that the reason people have cracked or even broken rear wishbones is because they are split, therefore may be experiencing torsional stress... and depending on how they are anchored to the frame... results can be disasterous.

Sam

[HarryT]

Great thread Sam. Beautiful workmanship.

[reece]

My vote is for this thread. Nice work and good pics.

[VoodooTwin]

Great tech thread! Glad to see this method (unsplit bones rear suspension design) is gaining traction. I did the exact same thing on my '33 frame, but not nearly as nicely as yours. Great workmanship!!

[Firepower71]

Great explanation, awesome work. Thanks!

[64ONEOFF]

I have always been interested in building a Tradtional car. I have been doing research and just talking to people. I REALLY ENJOYED YOUR POST. Thanks for the info.... And your right most cars and sedans usually DONT have a rear seat. Just a huge hump... I like your way much better