Technical Model A rear spring questions (updated with final pic)

Given your spring perches are 46.5 inches you will require a narrow spring

spring distance eye to eye will measure 41.5 inches

 

Update, spring replaced and figured I would replace the shocks as the existing ones are of unknown condition (monroe 31000's)
Here is what I have now.
Rear suspension measurements between shock mounting centers.
Measurements taken without shocks installed
fully compressed 12" (ratchet strapped diff to crossmember)
Fully extended 15.5" (frame on jack stands and lowered rear untill it was hanging.
This is with the axle level

From what I can gather I need a shock that has a compressed length less than 12" and an extended length greater than 15.5"

I have found a few options (mostly pickup trucks applications) and I am concerned they will be to "stiff"
The ones that were on it were Monroe 31000 12" x 19.5"
One option is the Monroe 32207 11.25" to 17.88" Stock equip on ford F100... seems like it might be overkill on an AV8
Another options is the So-Cal speed shocks 9.25" x 14.25"... maybe rebound and damping more suited to a hot rod.
Thoughts anyone?
Thanks.
Chappy

 

My experience of the SoCal shocks wasn't great. They changed a stock '32 roadster (fenderless) from a nicely sprung car to being uncomfortably hard. They're probably better suited to a much heavier car. I have some Bilsteins on a project '32 and they seem to be good and I've not heard anything but good things about them, but they're quite costly.

Chris

 

Chappy,

You mentioned that it’s back together. How Did the end result come out!?

 

When I got the old spring out it was clear that it was junk... really wore out. It was a 10 leaf pack and I could sit on it and get it to spread 4-6"
I got a posie narrow spring and fixed the shackle angle
I also gained some clearance on the on the spring to hairpin mount.
I was not able to bounce the car hard enough to get that spring to bottom out.
So now... I just want to dampen the bounce. The shocks that were on it were shot... real easy to compress and took forever to extend. I believe that the 12" compressed length of the 31000 got bottomed out.
Now I just need to find a shock that has 5/8" eyes on each end and meets the length requirements and isnt to "stiff"
I used the monroe shock chart that is floating around on here
I found the 32207's on rock auto for $17 each...I may just get a set and try them and see what happens. At least to find a starting point to work from.
Chappy

 

any updates Chappy?

 

I used VW beetle shocks on my 32 and liked them. Soft enough for a light car and long enough to get good travel.

 

I did some research on some shock lengths, working distances, compression and rebound rates, made some more measurements and ordered a set of Bilstein 5125 Series Shock Absorbers Part 33-187112. Just got them on this past weekend and took it for a short ride between crappy weather events. Its a huge improvement over what it was. I still need to redo the whole rear suspension but I have a feeling starting that project may turn into a whole new chassis project... so, this will keep me driving until then.
I am still fighting my brake pedal that gets harder the longer I drive issue. The things I have tried so far have not fixed it. I have a thread on that somewhere, I may have to revive it.
Thanks again for all of the help, suggestions, and information.
Chappy

 

Shock looks like a good choice, if it is soft enough.

Phil

 

I think it is close. compression is 203 pound-force, and rebound is 524 pound-force
Chappy

 

That's what I'm running on my 27 on 32 frame roadster.

 

Just curious if you could provide a picture of the new rear spring setup? Thx

 

Hydraulic shocks on light cars are the way to go. Most cars used them up to the 80's. After that the shock industry went to gas charge shocks. I looked and found some straight hydraulic shocks but they were more expensive than i wanted to experiment with. Sachs was one brand i found on RockAuto. I did find through my research that KYB excel-G series was the closest dampening to Hydraulic. I found that the Excel-G had about 40% of the "expanding pressures" of Gas adjust series. I've yet to get them on the car to test but right out of the box they do take substantially less effort to collapse for installation. The expanding force of a gas shock can be upwards of 75lbs of pressure. In my opinion that would have pretty adverse effect on the ride of a light car like a roadster or any A.

 

Be carful unloading that spring.

 

As requested, pic of the current configuration. Not perfect, but good enough to get me through to the rebuild.
Chappy

 

Looks much better Chappy!

 

Thanks for the picture - yes, that looks much better! And hopefully the ride is improved as well. lol

 

Did it change your ride height much?

 

Maybe a half inch or an inch measured from the tire to fender. Nothing really noticeable.
Chappy

 

If the body went up, get yourself a fat girl to ride with you. If it went down, look for a skinny gal. They come in all weights so just keep changing until you find one that fits

 

Looks good, functions within your range of acceptability, no car in a million pieces, stayed within budget. Ya done good.