T-bars vs Stored energy

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crossram383 said:
Dragin... Did you have shackles or sliders at this time ?

Cracked..Though I agree clamping the front of the leaf helps.
Unclamping the back of the leaf
plays a more important role
in allowing articulation of the axle housing under a load.
as well as having shackles vs. slider brackets to allow axle seperation/Rise from the chassis.
If I Were to USE sliders I would design them
similar to brackets found on Semi tractors
where the leaf spring is Allowed to SEPERATE from the frame
(within the bracket...Not Slotted like Dragins)
when the pinion climbs the ring gear
Under the Torque of acceleration .
Click to expand...

The purpose of clamping the spring is to keep the main leaf of that front segment from going S shape from the combination of twist and forward thrust, and then springing back and thus hopping the wheel as soon as the snubber contacts the floor. It really has nothing to do with traction per se.
Unclamping the rear in essence makes the back half of the springs more or less disappear during that initial axle rotation so that the snubber can contact the floor with full impact driving the axle into the ground. That's the purpose of having the long shocks. Contrary to popular opinion, if the relationship between the springs, snubber and chassis of the car is correct, the only reason to have shocks back there is because the rules say you have to have them.
 
draginmopars said:
shackles
Click to expand...
Hmm...Cracked may be right ?
Easiest fix would be to clamp the front ...couldnt hurt to try?

When you say the car shook...
do you think it was tire shake or the same wheel hop you have now ?
Reason I ask is I've had to low tire pressure in my cuda
and had the tire get planted so hard during the launch
the rim is almost touching the ground
distorting the sidewall and
causing major tire shake but not wheel hop ?


I just swapped out front and back axle housings in my
ramcharger (getting ready to plow some white gold)
because of some MAJOR wheel hop...only in reverse though ?
It turned out to be a rear pinion bearing seizing up (tight spot while rotating)
Who'da thought...I was stumped for a year on that one .

It'll be interesting to see how this plays out.
 
from my post #28

stiffer springs
lighter wheels, ET pro

Same results
after trying the snubber Aug. 2014, ran out of ideas.

looking at the four wheel drive
noticed the flat bottom spring

so took a set. cut the back half off and tried that




Aug 2014> last time raced
was the only time the front clamps were removed

With the SS springs,solid front eye, clamps

car still hopped

thats when swapped to a stiffer spring and the extra flat spring on the bottom of the stack
took the clamps off, because they were in the way of the flat spring, sitting against the bottom of the pack



before Feb, will put the SS spring back on and the Calvert shocks
 
Howard, the snubber could not function because of the sliders you have back there. The springs were too tight...not stiff...tight. When you put power to it, they turned into an S shape and then whipped back.
Put the stock 6 cylinder springs back in it...stock rear shackles. Put a pair of B Body shocks on it. Make sure the pinion is 2-3 degrees down with the car at rest. 1.5 -1.75 inch air gap at the snubber. Clamp the front of the springs....DONE! If that car won't go with that set-up I'll eat the damn thing.
Back in the day I was the driver on a 10 second 4 speed Hemi Challenger Street Race car, and that is the exact set-up we had. Hooked anywhere, anytime. Rear suspension was about the only problem we never had with that car!
 
crossram383 said:
Slidinitis: is a limited grip condition
usually found on chevies and other Non-Mopar vehicles
utilizing white castle brackets instead of shackles
where the rear of the leafspring
is NOT Allowed to SEPARATE away from the Chassis (and plant the tires).
symptoms generally include
loss of traction,and severe launch embarrassment.
due in part to mild or moderate wheel-hop,
(in cases where short chevy brackets
are installed on a Mopar
wheel hop can at times be severe
when the spring eyes contact the end of the slot.
we ALL KNOW most things associated
with GM tend to come up...a little short)

Dragin..do yourself a favor
and see if Tubs will trade
your "Limited-Grip Slider-Brackets"
for a pair of his "SURE-GRIP Shackle-Binders"
Let him put those museum pieces ... "under his car"
Click to expand...


So the shackle allows the rear of the leaf spring to separate from the frame and not travel in an arc ?
Please..........tell me more. LOLOLOLOLOL
The separation we look for is in the leafs , as the body rises , putting weight on and planting the rear tires.
I do have sliders on my car , for the record.
They allow the ride height to be about three inches lower and work just fine for street driving.
I will get the car to the track this spring ( I didn't finish this one till November ) and I'll bet you green dollars that they will work just fine there too.
I am not sure how to address a lot of your post because I haven't been in sixth grade for around 43 years.
 
tubtar said:
So the shackle allows the rear of the leaf spring to separate from the frame and not travel in an arc ?
Please..........tell me more. LOLOLOLOLOL
The separation we look for is in the leafs , as the body rises , putting weight on and planting the rear tires.
I do have sliders on my car , for the record.
They allow the ride height to be about three inches lower and work just fine for street driving.
I will get the car to the track this spring ( I didn't finish this one till November ) and I'll bet you green dollars that they will work just fine there too.
I am not sure how to address a lot of your post because I haven't been in sixth grade for around 43 years.
Click to expand...


I've been around Mopar Street and Race cars for nearly 40 years, and have NEVER seen any sort of practical application for rear shackle "sliders". There are sliders that have a practical use when using ladder bars with leaf springs...the purpose being to avoid binding when the two forward pivot points begin to move in different arches, but that's it.
The shackle/slider set up CAN NOT WORK EVER in a drag style application. Here's why.
When the rear rotates forward and the pinion snubber..or traction bar, limits the rotation, that force is used to raise the car. As the spring arches, the distance between the front and rear eyes becomes shorter, and the shackle allows this natural motion to happen by leaning forward with the spring.
With that rear slider set-up, in order for the spring to achieve arch, it actually has to distort itself...needs to become S shaped in reaction to the lifting force at the front.
A Slider will work perfectly when the only motion of the spring is a reaction to gravity...straight up and down forces. But when the motion is the result of torque reaction, all it can do is bind and cause twist in the spring.
I imagine with some real horsepower behind it, that set up could be EXTREMELY violent, and not in a good way.
 
whitepunkonnitro said:
Put the stock 6 cylinder springs back in it...stock rear shackles. Put a pair of B Body shocks on it.
Click to expand...

I'm NOT dis-agreeing with you.

That's the way it started
Stock/B-body shocks

first ever run- shakin

next SS springs
shackel bolts broke while changing to SS spring

Used the sliders CAUSE,, thats what I had at the time...

I then got lost> in thinking about spring rates CAUSE, it was doing the SAME thing as the six cylinder springs.
also thought, not enough tire>235 x 60 - 14 street tire
went to 235 x 60 - 15 ET street > made no difference

so, then changed gear to 4.10 and ET Pro (275 x 60 - 15)

When I get time

I'll go back to lighter springs > B-body shocks

If it still hops
the Calvert shocks
then I'll put rear shackels back on it...
last because they are the most work to install> cut out the sliders (welded in)


want to try ONE THING at a time
to find what one item is making it hop

Thanks to everyone for their input
 
whitepunkonnitro said:
I've been around Mopar Street and Race cars for nearly 40 years, and have NEVER seen any sort of practical application for rear shackle "sliders". There are sliders that have a practical use when using ladder bars with leaf springs...the purpose being to avoid binding when the two forward pivot points begin to move in different arches, but that's it.
The shackle/slider set up CAN NOT WORK EVER in a drag style application. Here's why.
When the rear rotates forward and the pinion snubber..or traction bar, limits the rotation, that force is used to raise the car. As the spring arches, the distance between the front and rear eyes becomes shorter, and the shackle allows this natural motion to happen by leaning forward with the spring.
With that rear slider set-up, in order for the spring to achieve arch, it actually has to distort itself...needs to become S shaped in reaction to the lifting force at the front.
A Slider will work perfectly when the only motion of the spring is a reaction to gravity...straight up and down forces. But when the motion is the result of torque reaction, all it can do is bind and cause twist in the spring.
I imagine with some real horsepower behind it, that set up could be EXTREMELY violent, and not in a good way.
Click to expand...

Housing sliders with ladder bars.........sure.
Spring sliders seem to work on a lot of cars , so I am optimistic.
The slider also allows the rear spring eye to move forward , so I am not sure I understand your point.
The difference is that the eye motion is linear rather than in an arc , but that is about it.
The pinion travel upward is controlled by the front spring segment , and with a clamped front segment , this will only go so far.
The rear segment will separate , fanning the leaves open if you will , and the leaf with the eye either rolls or slides forward depending on whether you use a shackle or slider.
My only concern was whether it would have enough range of travel , but I think I am good there.
I understand your point that these set ups worked into the eights.
Pro Stock ran leaf springs at one time.
And they worked too.
A lot of MoPar's technology in the leaf spring area was revolutionary when it was done.
They stopped that research in the late 80's or so.
And now the springs are made in Mexico and word round the camp fire is that durability has suffered.
So , what worked in the 70's will still work.
But there have been advancements too.
I know I am not cutting edge...........I will be very close to over powering leaf springs on my deal.
But I want to make them work and will spend some time doing just that.
Unless it scares the **** out of me.
Then , I'll cut the car up some more and go four link.
 
tubtar said:
Housing sliders with ladder bars.........sure.
Spring sliders seem to work on a lot of cars , so I am optimistic.
The slider also allows the rear spring eye to move forward , so I am not sure I understand your point.
The difference is that the eye motion is linear rather than in an arc , but that is about it.
The pinion travel upward is controlled by the front spring segment , and with a clamped front segment , this will only go so far.
The rear segment will separate , fanning the leaves open if you will , and the leaf with the eye either rolls or slides forward depending on whether you use a shackle or slider.
My only concern was whether it would have enough range of travel , but I think I am good there.
I understand your point that these set ups worked into the eights.
Pro Stock ran leaf springs at one time.
And they worked too.
A lot of MoPar's technology in the leaf spring area was revolutionary when it was done.
They stopped that research in the late 80's or so.
And now the springs are made in Mexico and word round the camp fire is that durability has suffered.
So , what worked in the 70's will still work.
But there have been advancements too.
I know I am not cutting edge...........I will be very close to over powering leaf springs on my deal.
But I want to make them work and will spend some time doing just that.
Unless it scares the **** out of me.
Then , I'll cut the car up some more and go four link.
Click to expand...

Ok, here is what you're missing with that slider vs shackle thing.
When the spring arches, it becomes shorter eye to eye. The shackle is actually an extension of the spring that allows it to become shorter while still being anchored. The shackle is adding three or so inches of spring length when it is asked to.
The slider binds the spring into a completely linier range of motion. That second articulation that allows the spring to grow longer or shorter with a shackle is gone. In other words, for the spring to arch, it can't ask for any extra length..it has no choice but to distort in order to become shorter. And, when you distort a spring, it will always snap back as soon as the force used to distort it is released. In this case, it would be the initial forward movement of the car. As soon as the mass is no longer at rest, snap! And that is EXACTLY what the video of the car is showing.
Howard ended up going this route because he had axle wind up due to the lack of a snubber. After he installed the snubber, the problem stayed the same because the slider was causing the issue I just outlined above. Kind of like putting a band aid on your thumb because you got shot in the foot and then wondering why the bleeding won't stop.
 
Tell this guy his Dart does not work with leaf springs and sliders...........
 

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whitepunkonnitro said:
Ok, here is what you're missing with that slider vs shackle thing.
When the spring arches, it becomes shorter eye to eye. The shackle is actually an extension of the spring that allows it to become shorter while still being anchored. The shackle is adding three or so inches of spring length when it is asked to.
The slider binds the spring into a completely linier range of motion. That second articulation that allows the spring to grow longer or shorter with a shackle is gone. In other words, for the spring to arch, it can't ask for any extra length..it has no choice but to distort in order to become shorter. And, when you distort a spring, it will always snap back as soon as the force used to distort it is released. In this case, it would be the initial forward movement of the car. As soon as the mass is no longer at rest, snap! And that is EXACTLY what the video of the car is showing.
Howard ended up going this route because he had axle wind up due to the lack of a snubber. After he installed the snubber, the problem stayed the same because the slider was causing the issue I just outlined above. Kind of like putting a band aid on your thumb because you got shot in the foot and then wondering why the bleeding won't stop.
Click to expand...

I have not used sliders, have looked at them but haven't used them. With that said, looking at a slider from a mechanical standpoint I just cannot agree with the part I highlighted above. IMO a slider DOES let the rear eye of the spring to move forward and aft. I don't understand how you can say it doesn't. When the arch becomes greater on a leaf spring (shortens up) the slider allows the rear spring eye/bushing/assy to slide forward (hence the name "slider"). When the spring flattens out the eye slides rearward. I'm not promoting sliders. Just pointing out that mechanically I believe you are looking at it wrong

I would like to add that I have not measured how much a slider will actually let a spring move for and aft so it's possible a shackle will let it move more, nevertheless a slider does not bind the spring solid forcing the spring to "distort, as you say" such as bolting it solidly to the frame would. If a slider worked that way what would be any purpose of having it? Just bolt the spring to the frame [-X
 
for 6.80,s you should be low 1.42/3 sixtys. when my 75 duster was running those numbers with s/s rear springs i found the more i clamped the front and rear segments then tightened up the comp 3 way shocks to full tight , the faster i went . ended up with 3 clamps on the front and 2 clamps one the back. if you have poly front strut bushings they stiffen the front up tremendously, not good for a race car. front t-bars may be shot, it happens. mopar chassis book tells you to loosen thing up, unclamp springs and such. once you are running low 11,s high 10,s you need to control the violent launch as you have found out. keep videoing and use the time slip numbers to verify you are going the right way.
 
Howard I've got a set of Cal-Tracks & Mono Springs,Rancho Shocks if your interested.
 
Eds Dart-

our best was 6.87
1.523 60 ft
99.6 mph

off the trailer

after that no telling what it will do

spin or hop

we are changing the upper control arms to heim joint arms
 
upper control arms will help. again though the poly front strut bushings and poly upper control arm bushings tighened the front so much even with no torsion bar in it took a floor jack to move the front suspension. i think your problem still is in the rear. you are going fast enough to need to control the violent launch. the front end is important too, your going the right way so keep it up, you will get there. mopar s/s springs and a good front end work well at the et you are running.
 
Eds Dart said:
upper control arms will help. again though the poly front strut bushings and poly upper control arm bushings tighened the front so much even with no torsion bar in it took a floor jack to move the front suspension. i think your problem still is in the rear. you are going fast enough to need to control the violent launch. the front end is important too, your going the right way so keep it up, you will get there. mopar s/s springs and a good front end work well at the et you are running.
Click to expand...

We were running the rubber bushings, I never did like the binding movement of them

This is what we are going to

jjklll.jpg
 
fishy68 said:
I have not used sliders, have looked at them but haven't used them. With that said, looking at a slider from a mechanical standpoint I just cannot agree with the part I highlighted above. IMO a slider DOES let the rear eye of the spring to move forward and aft. I don't understand how you can say it doesn't. When the arch becomes greater on a leaf spring (shortens up) the slider allows the rear spring eye/bushing/assy to slide forward (hence the name "slider"). When the spring flattens out the eye slides rearward. I'm not promoting sliders. Just pointing out that mechanically I believe you are looking at it wrong

I would like to add that I have not measured how much a slider will actually let a spring move for and aft so it's possible a shackle will let it move more, nevertheless a slider does not bind the spring solid forcing the spring to "distort, as you say" such as bolting it solidly to the frame would. If a slider worked that way what would be any purpose of having it? Just bolt the spring to the frame [-X
Click to expand...


The Slider allows the spring to move fore and aft, but it does not add actual length to the spring the way the shackle does.
 
several years back changed to uppers like you have and made my own front rod end type strut bars. could not believe the difference in how easy the front suspension moved. previously t bar adjustments didn,t seem to make much difference, after lossening up the front end now adjustments made a noticable difference, so much so that the shock adjustment becomes important. comp 3ways on full tight were ok till i stepped up the motor and wheelstand landings became bounce city. have strange double adj front and rear now. current car is a 68 dart back half four link so kinda apples to oranges but the leaf spring duster went through all the same problems you are having. again it,ll get there.
 
I have never used sliders or even known anyone who has, but I will add this. If sliders worked so darned good, they would be on purtnearbout everything that ever had leaf springs.

Mopars run 8 seconds and quicker with factory style leaf spring setups. To me, adding anything extra on top of that just ain't needed.
 
whitepunkonnitro said:
Obviously working just fine...along with the Ladder Bars or Caltracks he also has. The sliders can work as long as the rear axle is kept from any sort of rotation.
Click to expand...

It has leaf springs with Caltracs and 275/60 Drag Radials.........
 
D-50394 said:
It has leaf springs with Caltracs and 275/60 Drag Radials.........
Click to expand...


Right..the Caltracs completely eliminate axle rotation. With the combination of Caltracs and the sliders, he has basically eliminated the rear suspension all together..which is fine if you have enough horsepower and perhaps a trans brake to hit the tire hard enough to squat it.
 
whitepunkonnitro said:
Right..the Caltracs completely eliminate axle rotation. With the combination of Caltracs and the sliders, he has basically eliminated the rear suspension all together..which is fine if you have enough horsepower and perhaps a trans brake to hit the tire hard enough to squat it.
Click to expand...

They do not squat . I have never seen a car that worked with leaf springs squat.
 
D-50394 said:
They do not squat . I have never seen a car that worked with leaf springs squat.
Click to expand...

I second that.


I run Cal tracs and leave on a trans brake at 3500rpm.

My car does not squat. It picks the front tires up about a foot or two, and the rear axle seperates from the body. If you look at pics of my car in the pits vs pics of it launching, you can see way more of the top of the slick on the launch pic. If the body was squatting you would see less tire because the body would squat over the tire.
 
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