Packard Forum Index » V-8 (1955-56)

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Which won't lower the car that much, so no "in the weeds" stance. IF you lowered the cylinder 2" into the lower control arm, and made the overall extended length of the cylinder 2" longer, you'd have greater adjustability. The dimensions you're describing is back to the pancake type of cylinder, which you don't like. To lower the car any considerable amount, you'd need the arm coming off the torsion bar essentially even with the lower link pad surface of the lower control arm. A 2.75" collapsed length won't give you much.

Before we go any further, we ARE talking about an "in the weeds" stance when it's all said and done, correct?

Using my stripped 56 400 out back and diagrams in the Service Manual, here are some relevant 1st order dimensions:

Total up/down travel between snubbers: 4.5in (approx real)
Distance from lower control arm pivot to strut: 34mm
Distance ditto to snubber: 45mm
Distance ditto to C/L of tire: 56mm
the latter 3 being measured on the SM diagram.

Therefore, for every inch shorter/longer at the strut, the snubber moves 1.32in (45/34) and the wheel moves 1.65in (56/34).

Since total travel between snubbers is 4.5in, the "half-way" travel would be 2.25in up/down.

With a 4in strut (2.5in cyl travel), this yields 1.65in (1.25*1.32) snubber travel.

I submit that to achieve mid-position on the snubbers (2.25 up/down) on 50 year old T-Ls, the snubber length will have to be greater than 4in. Or conversely, the spring has sagged so that with a 4in strut, the lower snubber travel distance is less than 2.25in. [Measure yours to find out.]

A longer strut means the cylinder travel can be that much longer.

With a 4.5in strut, i.e., 3in cyl travel, this yields 1.98in (1.5*1.32) snubber travel.

With a 5in struct, i.e., 3.5in cyl travel, this yields 2.31in (1.75*1.32) snubber travel.

So, with an effective strut length of between 4.5in and 5in (closer to the latter), the lower snubber is bottomed out. I.e., the car's stance is "in the weeds."

BTW, the total tire/wheel travel WRT the body corresponding to above is 4.125in (1.65*2.5), 4.95in (1.65*3) and 5.78in 1.65*3.5). Any of those movements demonstrated at a car show would definitely WOW the crowd.

Also, putting the car's stance "in the weeds", was NOT my criteria, but Eric seems focused on that, hence the above analysis.

Craig

Since I'm not the mathematician you are, just wondered if your figures agree with bulletin 55-T1 where 1/2 in add'l strut length = approx 3/8 in add'l car height?

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Very good question! I had to think about that discrepancy for a while and then I realized that my analysis was focused entirely on the front suspension. Of course, in the real world, the T-L compensator is also involved.
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According to my figures, 1in strut length increase results in 1.65in wheel movement. When the T-L compensator detects the out of level, it will add more spring rate at the rear, raising it, but teeter-tottering around the center point, lowering the front back down to a final level distance of about half of my number, i.e. 0.82in. The factory number you quoted from 55-T1 is 0.75in for 1in strut length. These numbers are close enough for a first order analysis.
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So, the body height up/down numbers I stated above need to be halved because of the compensator.
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Of the two solutions, both will raise or lower the car, but to get extreme movement ("in the weeds"), you'd have to modify the lower control arm as Eric described or do something similar.
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If you mainly want to keep the above ground average center height the same while weight is added up to and including max capacity, then you could use the hydraulically adjustable link that I described instead. The vertical movement of roughly 2-3in would probably still WOW a crowd at a car show.
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Craig

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I got that in my head from this post here:


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Hence my "in the weeds" idea.

No harm, no foul.

The purpose of this thread was to have a discussion about my idea of a hydraulically adjustable T-L. That has succeeded, as there appears to be at least two ways to accomplish same. Maybe PMCC was thinking about something like this in their "improved" 1957 T-L design.

Craig

I think it's a good idea, it's just figuring out the logistics of it that's a PITA.

It's possible that a type of cantilever setup might be better anyway, I've been thinking about that since last night. See attached pic, and substitute a hydraulic operated cylinder for the shock.





You will have a greater distance of travel for a given cylinder with this setup, so you can have the "in the weeds" stance along with normal ride height. Now, fitting all this onto the lower control arm will be tricky, but I could do it if I had the right cylinder and a good welder. I DO still like my idea of running it off of the p/s pump, as it does away with having extra crap to fail, and to try and hide it so it's out of sight, which in a show car is important, IMHO.

Good ideas, Eric, and everyone else.

It's one thing to answer a Q about what "gefeebis fits that gefrabis in a 19xx mark Z."

It's quite another to ask the question, WHAT IF..., as per this thread.

Thanks everyone for participating.

Craig

I ALWAYS have good ideas Craig, you should already know this!

Have you given any thought to a telescoping or multi stage cylinder for the added length.