Maybe I missed reading it, but what shocks do is to reduce any weird harmonics in your springs. Springs will go back and forth (up and down) for some time after a hit like a pot hole. The shock is there to allow the spring to take the hit, then kicks in to smooth the rebound in the spring,,, sorry not a mechanical engineer. So a bottomed out shock will snap off the mount as the mount will be on a shear. A proper shock with a proper length will move freely with out jamming either the top or bottom mount. A proper shock should p*** the push test, push on the fender and the body should stop going up and down after two or three dips.
typo41....thanks....my shocks, I thought where set in middle play.....but there was not bottom or top to them. So they didn't bottom out or stretch beyond their top. As I have mentioned, I think the key to this is....one more leaf out and softer shocks to get the recovery movement I need and some weight is going to do the trick. I just didn't realize the "so light" rear in roadsters factor but......that's Hot Rodding....figuring out how to correct it.
2935Ford...I hope your OP is resolved, but in the meantime, this has potential to turn into pretty good overall tech thread: Maybe many people have just put them together & "got lucky" or said "it's drivin' like an 80 yr old car"...but I think there's a lot to be learned here that does not seem to be addressed often. Watchin' & Learnin'
Bam.inc...... I'm pretty sure my OP issue is resolved, thanks. What surprises me is.......all those AV8's out there on the road and I have not heard much back from them on their rides.........so, I might conclude....there is no issue and mine is a one off problem?
The shock dampens the movement in both directions. When the wheel goes up onto a bump the shock should resist the compression movement a bit, not very much but enough to prevent the wheel from lifting into the air (by the upwards momentum) after quickly being lifted to the top of the bump. Too much compression dampening resists suspension compression too much, and lifts the entire car instead of letting the suspension absorb the movement by compressing. Next, on the back end of the bump the shock should let the suspension extend just quickly enough to keep the wheel in contact with the ground as it drops away. Too much rebound dampening and the wheel looses traction because the ground drops away quicker then the wheel can extend, too little rebound dampening and the suspension extends too quick, basically acting as a pogo stick launching the car up as the suspension extends too quick every time it has been compressed. The springs... They "simply" carry the weight of the car. A soft spring allows big suspension movements, a hard spring minimizes movement. For a comfortable ride you more or less want as soft springs as possible to let the wheels follow the road surface without moving the body more than necessary, as long as you never bottom the suspension out. But on the other hand, soft springs (and no/soft sway bars) allow lots of body roll in the turns... Compromises, compromises...
Very doubtful this is a one-off problem. But this thread will certainly be referenced when I start on my RPU, so thanks for posting.
Ok First report for improving the ride......... had my son and his friend with their combined weight of 260lbs in the rumble seat made a great improvement in the ride at the rear. I'm thinking one rear leaf removal and soft shocks with 200lbs of added weight is going to do it. My next experiment will be the leaf out, boys back in and check the ride.
When I remove leaves from the rear spring for banger powered hot rods, I start counting from the bottom, and remove leaf #3 and leaf #5. Then I relocate the shorter leaves from the top to the bottom to set ride height. How many leaves get removed or relocated depends on which A spring you start with, whether it's for a roadster or sedan or whatever, it'll have a different number of leaves. But I usually end up with 5 or 6 leaves doing the work. I think the key is removing those two longer ones, as they let the spring flex more. This one had 6 leaves in the back, with shortened ones underneath to take up the extra space. scspl4 by general gow posted Aug 9, 2012 at 11:57 PM And this one has 5 leaves. Sachem At Elis by general gow posted Jul 7, 2015 at 4:54 PM
general gow......thanks. the way I understand it....the longer leaves are the softer right....the shorter the harder the ride? Do I have it backwards? I have the leaves removed cut to 12" and placed under the pack to fill the space. The B/T book ended up with 4 leaves......shocks....then still to rough 200lbs of weight was added.
you have it backwards, yeah. the longer ones are naturally easier to bend by hand, because of the leverage you have over them, but they are the leaves that provide the most suspension for the car. if you remove too many longer leaves, the car will sag. for example, i have only 4 leaves in the front, and it rides flat. i set it up light to hopefully bounce over the bumpy sand in the Race of Gentlemen, but it's awful on the road. a long leaf added back in will do way more to improve that ride than one of the shorter ones.
I hesitate to bring up math, but you could measure the spring compression with a scale. If/when you pull the spring pack make a jig to hold the spring in and push on it with a hydraulic press, and put some sort of scale between the spring pack and the press. F=kx or Force (in pounds) = spring constant X distance (usually inches). That way you can measure your spring constant before you mess with your springs and after/during tuning. Of course the devil is in the details because you need to hold the springs in the same orientation, shackles, etc as you have in your rod -and find a scale. Just a thought, Kelvin
I am surprised nobody has mentioned the fact you can tune you shocks effect by the angle at which they are installed. If they are straight up and down the exert more force on the axle. Lean them over at 45* and the will have more effective travel and less effect on the movement of the rear. And gas charged shocks have no place on a leaf sprung vehicle. They need a hydraulic dampener not gas ***ist. The old Pete and jakes were the same shocks as the front of a TNT snowmobile. Right down to made in Canada and the part number.
Exactly what I was about to say dump rat! No gas charged shocks! Oil damped only. My coupe has seven leaves,and has been apart half a dozen times to get the combination right. Keep fiddling,you'll get there!
Thanks everyone......I'll get it for sure. Lots of good suggestions here and hope it will help others. As soon as I get the pack apart and the removal of the second from the top....re install, I'll report back on it....
You can't tune shocks by changing the angle any faster than cutting off the mounts and re-fabricating the mounts
No... but you can prepare a number of diffrent mounting holes ONE time, and move the shocks around between them after that until you've found the best working one. Little extra work to add the optional extra holes when you fabricate the mounts to begin with.
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