Re: Setting up DA shocks
[Re: Wirenut]
#2817961
09/06/20 07:25 PM
09/06/20 07:25 PM
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Joined: Aug 2003
Posts: 43,718 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,718
Bend,OR USA
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Looking at both vids it looks like it is topping out the shock travel making the rear porpoise up ad down Did you compare the extended shock lengths on both sets of shocks? If not, if you can , do that now. If your new shocks are shorter at max extension than the old ones you may need to use shock extensions to help fix the extended length. If this is the case I might have a set of them, let me know if you need them or not Try removing the lower shock retainers and slip them off the lower shock mount and see how much more down travel you have on them, then try jacking the back of the car up with the rear end hanging down with jack stands under the rear sub frames and see how much rear shock travel downwards you have that way also. Please let us know what you find on this What does your rear spring shackle angel look like with the rear end hanging down all the way? It ET better in the 60 before so you know it will do it again with the proper fixes
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Setting up DA shocks
[Re: Wirenut]
#2817983
09/06/20 09:02 PM
09/06/20 09:02 PM
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Joined: Dec 2005
Posts: 12,289 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 12,289
Fulton County, PA
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Thanks for the input . I truly appreciate the help .
They are ss springs (don’t know which ones) .
They are mounted inboard , via dc relocation kit. Front eye is as close to car as adjustment holes allow. Rear hanger is through frame fairly close to floor . Angle looks good .
Tires are 31.25
Just throwing this out there. I have had this car for a few years . Until last year it pretty consistently 60’ed 1.40 to 1.42 with an occasional 1.39 And an occasional 1.45. That was with 20 year old ce 3-way shocks .
Seems like I am having to go through a lot of change to only get back to where I started.
It happens. It's called "losing the rabbit". Cab - I would bet a dollar that jacking that car up, putting jackstands under the chassis and leaving the rear hang, would not let it fall out any further than when it is on the ground. If there is so much arch that they are actually compressed, they need to be tossed.. Maybe need to be anyhow,
If the results don't match the theory, change the theory.
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Re: Setting up DA shocks
[Re: Cab_Burge]
#2817991
09/06/20 09:32 PM
09/06/20 09:32 PM
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Joined: Mar 2006
Posts: 9,973 MI, usa
dvw
master
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master
Joined: Mar 2006
Posts: 9,973
MI, usa
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It appears to be bound up at full rebound. I agree with Cab see where the shock length is. Any reason for the tall tire? Too much gear? A 28" would lower the rear a ton. The bind needs to be fixed before the shocks can do anything. I'd like to see a pic of the rear shackle. Since its close up in the frame is it hitting the frame? Doug
Last edited by dvw; 09/18/20 09:04 PM.
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Re: Setting up DA shocks
[Re: dvw]
#2818012
09/06/20 10:40 PM
09/06/20 10:40 PM
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Joined: Dec 2005
Posts: 12,289 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 12,289
Fulton County, PA
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A smaller tire will bring the rear of the car closer to level, but won't do anything to get the rear up in the car higher if the springs are holding it out.
It does look like it's porpoising or bouncing out across the concrete. But if you look close, the tire is bouncing up and down. The suspension has no movement.
If the results don't match the theory, change the theory.
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Re: Setting up DA shocks
[Re: CMcAllister]
#2818139
09/07/20 12:16 PM
09/07/20 12:16 PM
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Joined: May 2016
Posts: 630 Ct
Wirenut
OP
mopar
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OP
mopar
Joined: May 2016
Posts: 630
Ct
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About 3” of travel from at rest to hanging the axel.
Shocks have about 2.75” of travel beyond mounting point with axel hanging .
*****sorry don’t know why pics came out sideways and upside down******
Last edited by Wirenut; 09/07/20 12:21 PM.
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Re: Setting up DA shocks
[Re: Cab_Burge]
#2818182
09/07/20 02:32 PM
09/07/20 02:32 PM
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Joined: May 2016
Posts: 630 Ct
Wirenut
OP
mopar
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OP
mopar
Joined: May 2016
Posts: 630
Ct
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Thanks Mr C There is another hole forward of the current hole, but only on the passenger side . It’s like 1.25 more forward. Will this creat more travel ? Also what effect would unclamping the rear spring segment have ?
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Re: Setting up DA shocks
[Re: Wirenut]
#2818187
09/07/20 02:39 PM
09/07/20 02:39 PM
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Joined: Aug 2003
Posts: 43,718 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,718
Bend,OR USA
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Unclamping the rear will make it, the rear half, separate more, not good Moving the upper hole forward to increase the rear shackle angle will allow the springs to move forward without going past 90 degrees, straight up and down on the shackles, and not pulling the back of the car down as it goes past 90 degrees Now get to work fixing it Your car looks a lot like my old pump gas Duster but higher in the rear end. I had ladder bars with coil overs installed on it That car would hook up in a mud puddle in a rain storm AKA aside, it flat hooked
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Setting up DA shocks
[Re: Cab_Burge]
#2818222
09/07/20 04:49 PM
09/07/20 04:49 PM
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Joined: May 2004
Posts: 3,210 robin hood country
deaks
master
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master
Joined: May 2004
Posts: 3,210
robin hood country
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9 PSI seems low to me, my 31x10.5 w hoosiers, wouldn't 60ft under 13 psi.
69 Dart GTS 440 mopar .590 cam, Edelbrock heads, 3200# best et 6.45, 106.78, 10.14, 132.88 mph, 1.47 60ft best 60ft 1.36
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Re: Setting up DA shocks
[Re: deaks]
#2818403
09/08/20 05:28 AM
09/08/20 05:28 AM
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Joined: May 2016
Posts: 630 Ct
Wirenut
OP
mopar
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OP
mopar
Joined: May 2016
Posts: 630
Ct
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9 PSI seems low to me, my 31x10.5 w hoosiers, wouldn't 60ft under 13 psi. I have run them as low as 8 . The 60 has typically been better the lower the psi
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Re: **update w/ video** Setting up DA shocks
[Re: Wirenut]
#2818406
09/08/20 06:28 AM
09/08/20 06:28 AM
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Joined: Dec 2016
Posts: 1,124 Usa
A39Coronet
super stock
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super stock
Joined: Dec 2016
Posts: 1,124
Usa
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Not gonna pretend I'm a 60' guru but if you slow the video down you have 5 almost 6 sidewall wrinkles. I've always been told 2-2.5 and any more the tire is wadding up and acting like a spring. If you watch, that's what I'm seeing, the tire wads up, and releases momentarily and initiates the bucking. Even as big as those are, I'd be going the other direction in PSI. I think you're trying to compensate some other issue by continuing to drop pressure.
Last edited by A39Coronet; 09/08/20 06:29 AM.
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Re: **update w/ video** Setting up DA shocks
[Re: A39Coronet]
#2818409
09/08/20 06:59 AM
09/08/20 06:59 AM
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Joined: May 2016
Posts: 630 Ct
Wirenut
OP
mopar
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OP
mopar
Joined: May 2016
Posts: 630
Ct
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Not gonna pretend I'm a 60' guru but if you slow the video down you have 5 almost 6 sidewall wrinkles. I've always been told 2-2.5 and any more the tire is wadding up and acting like a spring. If you watch, that's what I'm seeing, the tire wads up, and releases momentarily and initiates the bucking. Even as big as those are, I'd be going the other direction in PSI. I think you're trying to compensate some other issue by continuing to drop pressure. Yes I tend to agree with you. I will try and correct the rear shackle angle in hopes to create more travel or spring movement .
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Re: **update w/ video** Setting up DA shocks
[Re: mopar dave]
#2818463
09/08/20 10:12 AM
09/08/20 10:12 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I didnt see where you said the total weight as you leave the line.. any tire will run best with a certain pressure for a given weight.. my car is light and I run 6.5 to 6.75 PSI and above that it spins.. you should start with GOOD tires not some set thats been on it for 10 years.. you would be using that as your zero point which could be wrong to start with.. tires dont last as long as people think.. on mine the tire is pretty well shot at a 100 passes then the 60' starts falling off.. I could tell by the 60' numbers the side walls would be shot.. that was with tubes to help stiffen the side walls.. to look at the tire it looked fine and had plenty of life let in it.. I use to sell them off.. my 60' would range from 1.19 to 1.22 then I got a new set.. there is no reason for a big burn out.. that just burns up the tire.. just needs to get a light bit of smoke to clean and warm them up.. so start fresh and dont waste your time trying to tune the suspension which comes next
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Re: **update w/ video** Setting up DA shocks
[Re: justinp61]
#2818476
09/08/20 10:37 AM
09/08/20 10:37 AM
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Joined: Jan 2003
Posts: 13,492 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,492
Marion, South Carolina [><]
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Have you tried more air pressure? In the photo with the shackles is the drivers side almost vertical? As already mentioned if you have to move the top shackle mounts in the frame I'd go ahead and install sliders, it'll be a much easier job.
Not a chassis tuner so take this with a dump truck load of salt. In the videos I see three things, one it appears just as the drivers front tire comes off the track the rear tire unloads. Two, there is almost no movement in the rear, separation or compression. Three, the rear tire needs more air. I'd add some air to the slicks, slow down the rebound in the front and loosen both the compression and rebound in the rear. In that order.
The above and $1.75 will buy you a cup of coffee in some places. I have to agree w/ all of this.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 4 speed, Dana 60 '71 Demon 340, no drivetrain, on blocks behind the barn '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: Setting up DA shocks
[Re: Wirenut]
#2818479
09/08/20 10:41 AM
09/08/20 10:41 AM
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Joined: Oct 2004
Posts: 2,849 Connecticut
FurryStump
master
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master
Joined: Oct 2004
Posts: 2,849
Connecticut
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Ok thank you both.
Unfortunately I don’t have anyone to video Man! I was there that day. I will be at LVD sat and sun on 9/12-9/13. If you are going back, stop by and I will video the cars launch for you. This is my car.
Last edited by FurryStump; 09/08/20 10:42 AM.
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