Re: ADJUSTABLE STRUT RODS - different designs
[Re: Supercuda]
#1948045
11/09/15 12:36 PM
11/09/15 12:36 PM
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Joined: Dec 2003
Posts: 23,554 Here
jcc
No soup for you!!!
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No soup for you!!!
Joined: Dec 2003
Posts: 23,554
Here
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If I understand you correctly, I disagree. Rethink that.
I'm with Helmuth Hübener, and no soup is being served today.
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: Supercuda]
#1948074
11/09/15 01:45 PM
11/09/15 01:45 PM
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Joined: Dec 2004
Posts: 804 central CT
cudazappa
super stock
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super stock
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Posts: 804
central CT
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If the centerline of the ball joint setup you mention was in line with the plane of the LCA pivot you'd remove the conflict. The strut will always have an intersecting arc to the LCA in a stock Mopar setup. As such, there will always be a "conflict." Modern suspensions get around this by having 2 mounting points for the LCA. (thus not needing a strut arm)
1971 Challenger
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: jcc]
#1948078
11/09/15 01:49 PM
11/09/15 01:49 PM
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Joined: Dec 2004
Posts: 804 central CT
cudazappa
super stock
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super stock
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central CT
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You covered a lot pertinent ground, but you have not mentioned that a rigid pivot strut rod, induces a small arc in the LCA as it moves up and down. The OEM allows for this by using rubber I suspect. Almost all other LCA bushings, I suspect even the delrin bushing will allow that small motion. If that arc was resisted, you would have bind. Granted the induced arc is minor, but then those who are making this upgrade "think" they are reducing unwanted movement in the first place. I suspect the LCA might even flex in this new arc induced by a rigid strut rod mounting, since the LCA main strength is vertical by its greater height cross section. Of course those that add the lower rein forcing plate would reduce this flex, and therefore drift closer to bind, not a wanted outcome. All this means to me going full circle, not sure why bother with the upgrade if the installed rubber bushings are in good shape and tight, for anything short of Nascar use.
For discussion sake, is there consensus the strut's biggest and most important loading is when under braking?
The purpose is to control the arc's of the strut and LCAs. As such, there will be a defined point during the travel of the LCA. With this defined point you can adjust/modify other items for beneficial alignment settings. If the strut is "floating" in a bushing, then the position of LCA becomes more dependant on acceleration, braking, or during turning as they apply force on the suspension.
1971 Challenger
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: cudazappa]
#1948124
11/09/15 03:12 PM
11/09/15 03:12 PM
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Joined: Dec 2003
Posts: 23,554 Here
jcc
No soup for you!!!
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No soup for you!!!
Joined: Dec 2003
Posts: 23,554
Here
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Yes, but the last point I was making, of all those forces, I suspect braking loads the "brake" strut the most, and I also suspect by a large factor.
I'm with Helmuth Hübener, and no soup is being served today.
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: Mopar Mitch]
#1948155
11/09/15 04:26 PM
11/09/15 04:26 PM
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Joined: Jan 2010
Posts: 1,443 NW Chicago suburban area
Mopar Mitch
OP
pro stock
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OP
pro stock
Joined: Jan 2010
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NW Chicago suburban area
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T/Anks to all who've replied... FWIW... my LCA bushings are ~30 years old, as well.. and still appearing a-ok .. RUBBER. (~30 yrs ago poly lca bushings weren't avlbl... so.. I simply replaced the complete lcas which came with new factory lca rubber bushings.)
As to pulling the lcas a bit forward, using the adjustable struts, I can better understand that's probably not desirable as it'll disturb the lca bushings -- poly potentially to where out more quickly... but rubber can withstand and flex, hence longer life.
I'm unfamiliar with the RMS struts... I'll look them up.
I've recently had my kframe welded, and also the lca plates added. Engine bay is being repainted very soon.... been sanding, prepping, etc (show-quality!).
Despite the factory struts w/rubber bshgs, factory lcas and rubber lca bshgs, the car has always been tight and great handling (SCCA competition AX, and recent HSAX/HPDE, and street/hwy)... the overall suspension setup I have works great: 1.24 TBs, 225/5 flexaform mono leafs, 1.25 F, 1.0 r sway bars, Red Koni Ds, balance corner weight.. 52% f, 48%r. SO... with the engine out for a rebuild, the front end is being gone through.
Mopar Mitch
"Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers!
Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: cudazappa]
#1948367
11/09/15 08:43 PM
11/09/15 08:43 PM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
About to go away
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About to go away
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Posts: 14,889
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If the centerline of the ball joint setup you mention was in line with the plane of the LCA pivot you'd remove the conflict. The strut will always have an intersecting arc to the LCA in a stock Mopar setup. As such, there will always be a "conflict." Modern suspensions get around this by having 2 mounting points for the LCA. (thus not needing a strut arm) Yes, but if you went the balljoint route you'd be smart to relocate the thing to remove the conflict, hence my comment about the line (shouldn't of said plane) of the LCA pivot point intersecting the center of the ball joint.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: Mopar Mitch]
#1948454
11/09/15 11:13 PM
11/09/15 11:13 PM
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Joined: Feb 2011
Posts: 4,302 Nebraska
72Swinger
master
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master
Joined: Feb 2011
Posts: 4,302
Nebraska
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T/Anks to all who've replied... FWIW... my LCA bushings are ~30 years old, as well.. and still appearing a-ok .. RUBBER. (~30 yrs ago poly lca bushings weren't avlbl... so.. I simply replaced the complete lcas which came with new factory lca rubber bushings.)
As to pulling the lcas a bit forward, using the adjustable struts, I can better understand that's probably not desirable as it'll disturb the lca bushings -- poly potentially to where out more quickly... but rubber can withstand and flex, hence longer life.
I'm unfamiliar with the RMS struts... I'll look them up.
I've recently had my kframe welded, and also the lca plates added. Engine bay is being repainted very soon.... been sanding, prepping, etc (show-quality!).
Despite the factory struts w/rubber bshgs, factory lcas and rubber lca bshgs, the car has always been tight and great handling (SCCA competition AX, and recent HSAX/HPDE, and street/hwy)... the overall suspension setup I have works great: 1.24 TBs, 225/5 flexaform mono leafs, 1.25 F, 1.0 r sway bars, Red Koni Ds, balance corner weight.. 52% f, 48%r. SO... with the engine out for a rebuild, the front end is being gone through. Mitch I am excited to hear you're making IMPROVEMENTS and I really think you will be pleased with some heimed/adjustable strut rods. Like I said earlier they are not for more caster, they are to precisely locate your LCA and preload your LCA bushing to YOUR liking, where its happiest. Calling them "Adjustable Strut Rods" is kinda misleading. RMS, Reilly Motorsports, home of the "Alter K" is where I bought mine, and they are exactly what I wanted, no hype they just work and didn't break the bank. Peter makes Delrin LCA bushings, those and greasable LCA pins with some new strut rods would be the only 2 basic "improvements" I think I would add to your car.
Mopar to the bone!!!
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: Mopar Mitch]
#1948577
11/10/15 02:56 AM
11/10/15 02:56 AM
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Joined: Feb 2011
Posts: 4,302 Nebraska
72Swinger
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master
Joined: Feb 2011
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Nebraska
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That is a modded Uniball.
Mopar to the bone!!!
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: Supercuda]
#1948826
11/10/15 03:29 PM
11/10/15 03:29 PM
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Joined: Dec 2004
Posts: 804 central CT
cudazappa
super stock
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super stock
Joined: Dec 2004
Posts: 804
central CT
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Yes, but if you went the balljoint route you'd be smart to relocate the thing to remove the conflict, hence my comment about the line (shouldn't of said plane) of the LCA pivot point intersecting the center of the ball joint. So, I've been playing with this in my head and some scrap paper now. Provided that the center of the heim/ball joint is in line with the LCA pivot and t-bar there will be no bind. Ever. The strut actually moves in a conical motion, so the arc is the same as the lca. Therefore there is no intersecting arc. It is the same arc. However if that pivot is not in line, there will be a conflicting arc. Obviously the larger the arc, the less influence it has. Much like a longer panhard bar will shift the rear end less than a shorter panhard bar. I was going to explain the intersecting arcs and in doing the geometry, discovered this for myself. I feel smart and stupid at the same time. If anyone already knew this, kudos to you.
1971 Challenger
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: 72Swinger]
#1948833
11/10/15 03:45 PM
11/10/15 03:45 PM
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Joined: Jan 2010
Posts: 1,443 NW Chicago suburban area
Mopar Mitch
OP
pro stock
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OP
pro stock
Joined: Jan 2010
Posts: 1,443
NW Chicago suburban area
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72Swngr.. I'm doing these mods only because the car is apart (engine out)... so, now is the time. Otherwise it has handled superbly even with the rubber lca bushgs and stock/rubber struts (replaced them all new about 30 years ago).
I wonder if the RMS, PST and Hotchkis adjustable strut rods are all identical? Same manufacturer for all? They look identical except for the paint/color/markings. Does anyone know the difference?
Mopar Mitch
"Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers!
Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: Mopar Mitch]
#1948875
11/10/15 05:01 PM
11/10/15 05:01 PM
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Joined: Feb 2010
Posts: 270 Mountain View, CA
68rrunner
enthusiast
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enthusiast
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Posts: 270
Mountain View, CA
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If you look at Construction, the PST and Reilly units appear to be the same and most likely someone is doing private label for the other. PST RMS [img] https://www.reillymotorsports.com/store/image.php?type=D&id=143[/img] However the Hotchkis units are quite different in construction. The most advantageous part of the Hotchkis design in that the Strut rod engages the LCA the same way the factory unit does, by resting on a machined shoulder. The other units bolt in from the rear which means that the engagement is the clamping force of the faster and the face of the rod which could allow movement of the threaded section. I've seen folks who install Heims onto the threaded section of of a fastener and over time and cycles, the threads will "waller" out the hole. No good, especially if that fastener shears or backs out...you have nothing holding your strut rod to the LCA.
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: Mopar Mitch]
#1948882
11/10/15 05:06 PM
11/10/15 05:06 PM
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Joined: Oct 2015
Posts: 43 Santa Fe Springs, CA
Jon @ Hotchkis
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member
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Santa Fe Springs, CA
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In addition to what Dan said: We also use a billet steel front clevis mount, where as the other brands use a broken piece of plate steel; our front mount is quite a bit stiffer and stronger, while in my opinion being cleaner. (I only have a good picture of our new Mustang struts, but the same clevis is used)
Last edited by Jon Rasmussen; 11/10/15 08:35 PM.
Hotchkis Performance 8633 Sorensen Ave. Santa Fe Springs, CA 90670 Phone: 562-907-7757 x224 Fax: 562-907-7765
Hotchkis Performance East 9075 Highway 152 Mooresville, NC 28115 704-660-3060
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: cudazappa]
#1948898
11/10/15 05:18 PM
11/10/15 05:18 PM
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Joined: Dec 2003
Posts: 23,554 Here
jcc
No soup for you!!!
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No soup for you!!!
Joined: Dec 2003
Posts: 23,554
Here
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Yes, but if you went the balljoint route you'd be smart to relocate the thing to remove the conflict, hence my comment about the line (shouldn't of said plane) of the LCA pivot point intersecting the center of the ball joint. So, I've been playing with this in my head and some scrap paper now. Provided that the center of the heim/ball joint is in line with the LCA pivot and t-bar there will be no bind. Ever. The strut actually moves in a conical motion, so the arc is the same as the lca. Therefore there is no intersecting arc. It is the same arc. However if that pivot is not in line, there will be a conflicting arc. Obviously the larger the arc, the less influence it has. Much like a longer panhard bar will shift the rear end less than a shorter panhard bar. I was going to explain the intersecting arcs and in doing the geometry, discovered this for myself. I feel smart and stupid at the same time. If anyone already knew this, kudos to you. This also assumes LCA and Strut have same pivot length?
I'm with Helmuth Hübener, and no soup is being served today.
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: jcc]
#1948901
11/10/15 05:20 PM
11/10/15 05:20 PM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
About to go away
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About to go away
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Posts: 14,889
up yours
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This also assumes LCA and Strut have same pivot length? They would have to in order to work in the scenario we are talking about, who knows what the stock setup is. I can't imagine it's too far off or bump steer would be interesting.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: 68rrunner]
#1948949
11/10/15 05:59 PM
11/10/15 05:59 PM
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Joined: Dec 2004
Posts: 804 central CT
cudazappa
super stock
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super stock
Joined: Dec 2004
Posts: 804
central CT
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However the Hotchkis units are quite different in construction. The most advantageous part of the Hotchkis design in that the Strut rod engages the LCA the same way the factory unit does, by resting on a machined shoulder. The other units bolt in from the rear which means that the engagement is the clamping force of the faster and the face of the rod which could allow movement of the threaded section. I've seen folks who install Heims onto the threaded section of of a fastener and over time and cycles, the threads will "waller" out the hole. No good, especially if that fastener shears or backs out...you have nothing holding your strut rod to the LCA. Good point! Also look at the forward heim on the Hotchkis. I have to inspect mine to see if they used more than a standard bolt or I suspect that heim may be resting on threads, as well. Only about 200mi on my setup so far so I'm sure no wear. Dan Weishaar posted about this regarding the Hotchkis UCAs a while back and I made sure I grabbed new Socket Head Cap Screws and modded them for the brackets. My only complaint about the Hotchkis ones is the washer stack used to locate the forward mount is cumbersome (at least when your car is only 12" in the air and your head is against the concrete) and I would have much preferred a machined step washer like the RMS/PST unit. (something else to make!)
1971 Challenger
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: geo.]
#1949230
11/11/15 02:36 AM
11/11/15 02:36 AM
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Joined: Jan 2003
Posts: 27,596 So Cal
autoxcuda
Too Many Posts
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Too Many Posts
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Posts: 27,596
So Cal
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Wonder how the Nichels stock car arrangement would compare. They welded a sleeve into the k-member, screwed in what looked like a typical Mopar ball joint, and joined it to a shortened two piece strut rod, with a threaded collar. A tie rod type adjustment was used to change the length as needed. Would work like the Mustang ones that nstgl1970 posted about. In other words, perfectly fine and with more resistance to wear than a spherical rod end.
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Re: ADJUSTABLE STRUT RODS - different designs
[Re: geo.]
#1949378
11/11/15 01:12 PM
11/11/15 01:12 PM
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Joined: Jan 2003
Posts: 5,406 Pikes Peak Country
TC@HP2
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master
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Wonder how the Nichels stock car arrangement would compare. They welded a sleeve into the k-member, screwed in what looked like a typical Mopar ball joint, and joined it to a shortened two piece strut rod, with a threaded collar. A tie rod type adjustment was used to change the length as needed. That's similar to what I proposed, only I'm saying don't bother with the welding and screwing in the ball joint. You'll eventually fatigue the threads and have to replace the sleeve. Instead, use a bolt in ball joint.
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