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Discussion Starter #1
I have a 1993 LX Yellow Feature vert I am reviving. From what I can tell it has ~160k on the chassis. It has stock suspension from what I can tell except for some caster camber plates on the front and a 5 lug conversion using Lincoln Rotors.
Having said that, I am looking to set it up for some daily driving, maybe a pass or two at the local eighth mile track for fun after work. Nothing serious. But the suspension is old and tired now. If I could swing all of it, it was thinking about some Koni Orange shocks and struts, FMS B-Springs, UMI Upper and Lower Rear control arms, removing the quad shock (?) and replacing the bushings on top of the rear axle housing (where the RUCA attaches)..
My other option, is just to do the rear. But, if I do that, I'll just replace the rear springs with some new stockers, the Koni Orange shocks and the UMI Upper and Lower Rear Control Arms and a new pair of RUCA axle bushings until I see how the new rear setup works.
My wheels are Mach1 wheels 17x9 with 255 40 17 in the front and 275 40 17 in the rear. I think the fronts are too big (wish they were 17x8 :rolleyes:). I don't want any rubbing issues or having to roll the fenders etc.

Please advise.....

Thanks!
 

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The oem Mach 1 wheels are 17x8, FYI:)
 

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A little confused. If the car is primarily a DD, those arms are likely to provide potential bind when cruising around. An MM set-up will provide you with the traction needed at the track but at the same time not add bind. The difference will be a better ride (at least as good as possible with the stock 4-link) and handling.
 

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Discussion Starter #4
The oem Mach 1 wheels are 17x8, FYI:)
These are Mach1 replica wheels, not OEM (I wish they were;))

A little confused. If the car is primarily a DD, those arms are likely to provide potential bind when cruising around. An MM set-up will provide you with the traction needed at the track but at the same time not add bind. The difference will be a better ride (at least as good as possible with the stock 4-link) and handling.
I don't quite understand what you mean by "bind". Also, I assume that you mean doing the Upper AND Lower rear arms. On MM's site, I only saw Rear Lower Control Arms. Please have patience, because I am a bit of a noob when it comes to suspension stuff. That's why I am seeking the advice of the pros on this site! ;)
 

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I don't quite understand what you mean by "bind". Also, I assume that you mean doing the Upper AND Lower rear arms. On MM's site, I only saw Rear Lower Control Arms. Please have patience, because I am a bit of a noob when it comes to suspension stuff. That's why I am seeking the advice of the pros on this site! ;)
Not a problem. On a Fox chassis the rear suspension is the main culprit for poor handling, mostly the uppers. This is because the uppers were designed to perform two functions: (i) axle roll control (as the car accels/decels); (ii) axle lateral control (side-to-side as the car turns). During a typical corner, the uppers are doing these two duties at the same time. In order to accomplish this task, Ford designed the bushings and arms to grow (soft rubber) and twist (u-channel arm) as they articulate. Despite this compliance, the arms can only grow and twist so much before they reach maximum and "bind." When bind occurs what spring rate the rear had goes to infinity and the car generally snap over-steers - or the back comes around. Once this starts, the driver is pretty much along for the ride until the car stops.

The lowers just do one job and that is squaring the axle with the fron suspension - a locating device. In isolation, the lowers are not as critical to suspension articulation as the uppers and one can use boxed arms poly and spherical bushings.

A common error when upgrading the rear suspension is replacing the upper pieces with poly and/or spherical bushings and length adjustable or boxed tube arms. Doing so removes the compliance necessary for the design to function as intended; bind generally occurs much sooner at lower speeds. When combined with a similar approach with the lowers we have a recipe for poor street manners.

MM's theory is upgrade the lowers with a tube arm and poly bushings at the chassis end and spherical at the axle end (or at both ends in the heavy duty versions). But the uppers should remain stock channel arms with compliant rubber bushings. This is why the only sell the lowers. Actually, they want the end-user to remove the uppers altogether and replace them with a T/A (roll control) and PHB (lateral control). This transforms the rear suspension; more traction, better and predictable corner entry/exit, and better ride quality (yes, the bind is gone so the ride actually improves).

However, MM also knows that not everyone wants or can afford a T/A. Thus, they recommend the lowers with stock uppers (which I believe they sell too). Despite this, the uppers will still bind at some point during articulation so the ride quality and potential undesirable handling is present but at least you haven't made it worse that likely would occur with the other offerings.
 

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Discussion Starter #6
Thanks for the nice explanation! I did speak to MM and UMI. It seems that there are definitely several opinions on the matter. :blam: So, I ended up getting MM's opinion and UMI's opinion (as well as the shop's opinion and other members on this site). MM opinion is just the way you explained it. UMI pretty much said there uppers with urethane bushings will work just as designed. That's why they designed them that way and they have been racing and auto.x.ing for years with there own stuff testing, improving etc. The harder urethane bushing vs the rubber one does make sense as far as MM's opinion (so there is adequate movement per the Ford engineers design).

So, tomorrow, I am going to the shop that has the car now and discuss the matter of doing the lowers and swapping bushings on the uppers and axles housing vs the UMI (or UPR) setup to see how much difference the install would be.
Also, I was told that the 1993 uppers are basically the same as the discontinued FMS Uppers. So, that was nice to know (assuming its correct :idunno:).
 

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Can't argue a point that appears concerned about sales. Even MM uses poly but those are three-piece bushings; allows some slipage.

I do know about bind from stock to non-stock. Even when I had the rod-ended PM3L I hit bind. Granted, for a different but related reason but it still occured. I did 2 360s on an A/X course, and stayed on-course! The cone chasers and anouncer were very impressed with my feat. Still I wasn't expecing this from a rod-ended piece.

I've not had that problem since moving to a T/A.
 

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Discussion Starter #8
I just got back from the shop that has my 93. I inquired about re-bushing the upper arms (since I was told they are the same as the old FMS ones in 1993) and the axle bushings. He said the axle bushings are a PITA. he said it'll be about $250 to redo all the bushings! :eeek: I guess with the money I'll save by not having to buy new upper arms (and still have to do the axle bushings) it'll work out. I'll probably get to ordering the parts tomorrow or Thursday, unless ya'll have some other suggestions. He said the springs in the car now should be fine, just get new isolaters, too.
 

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Discussion Starter #11
The UCA axle bushings are super easy to R&R. Just use this.

Rear Upper Control Arm Bushing Tool

https://youtu.be/af1S7HEZUwU

The tricky bushings are the UCA chassis bushings. You need to build tooling to keep the UCA from deforming when removing and installing them.
Thnaks! That makes it look too easy!

I have this tool and have R&Rd several sets - piece of cake. Even places the bushing in the correct position.
Just wondering, how much harder it would be with the axle still installed on the car?
 

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With the car in the air? Easy peasy. With the car on jackstands on your driveway? A pain in the ass. Ask me how I know.
 

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Discussion Starter #14
If I am going to attempt to replace the RLCAs as well as possibly re-bushing the RUCAs and change out the shocks, wouldn't the axle be hanging down a little lower so as to be able to get better access to those bushings?
 

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When I did mine I had to pay attention to the center brake line tension. As a result, I changed one thing at a time so I wouldn't overly stress the line. Ultimately, the axle hung at the ends of the shocks and one upper when I changed the upper axle side bushings.
 

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Discussion Starter #16
Thanks for all the replies! I was doing some research last night and I was on LMR's site. I'm thinking of replacing the uppers AND lowers with their SVE stuff. I know it is cheap Chinese stuff, but, the uppers AND lowers both come with rubber bushings and LMR gives a one year warranty. It seems like rubber is the preferred setup, at least with the uppers. The lowers would be easy enough to change out later if I don't like them for some MM arms. However, the guy I spoke with on the phone said he has used these SVE arms on several fox body cars and has had no issues. The other thing is price. For $140, it might be worth a try. This car has given me two BIG suprises lately. One, the clutch in June (was supposed to have been brand new when I got the car) and this suspension problem. All this while I am in the middle of finishing up doing a "light restoration" on my 1993 Chevy 1500. :rolleyes:

Thoughts on the SVE stuff?
 

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Discussion Starter #17

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I'd just go to a junkyard and pull some stock control arms (pretty sure 4-banger arms are the same, should be stupid cheap at any junkyard) and replace the pumpkin-side UCA bushings with MM's tool. Those SVE uppers will cause the same bind problems we are telling you to avoid. The stock, non-boxed units at least flex in torsion.
 

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Those uppers appear to not permit any twisting like the stock arm's channel design. Recall, the converging 4-link design depends on the uppers ability to both twist and deflect during articulation. The less twist/deflection you insert into the design, the quicker bind will occur causing unpredictable handling.
 

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Discussion Starter #20
So, then, the preferred situation is to get the MM lowers, remove the quad shock, re-bushing the stock upper and axle bushing (if $$ allows for axle bushing), install the Koni Orange shocks, put new isolators on the stock springs and get to driving! Is that what I'm hearing, lol?
 
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