geez looks like i;m one of the few who did the DC trailing arm swaparoo huh? puts Mugen trailing arm bushing in safe place
Scott, did I read that right? From what you said it sounds like the crx bushings are different from the 4th gen civic bushings? I thought the rear suspension was the same for those two cars. I gotta find out cause my gf’s crx is definitely gonna need those bushings eventually…
Robbie, nah, I did the DC2 arms too, well, I put mugen’s in 'em.
Duy: I totally agree. Eventhough I changed many other bushings at the same time and got the car aligned a little better… I could definitely tell the tail end was drastically different. Much smoother and held the road better. Before the tail of the car always rode a little rough. I had always attributed this to pretty stiff springs, fairly stiff shocks, stiffer sidewall tires, and the road being rough. Now I know this “roughness” and actually some strange noises :uhoh: were due to those bushings being completely shot. Definitely a mod I should have done a long time ago.
Colin, apparently because the Si had rear discs, the arm is
“more like the DA arm”… Maybe even exactly… I know the part # isn’t the same, but possibly the same dimensions.
Hmm, that doesn’t seem to make sense. What part numbers have you checked? Both ed8 and ed9’s came in an “si” version. However in 88 and maybe 89 the Si version still came w/ drum brakes. Have you compared part numbers between say a 91 civic si and a 91 crx si?
Also, the differences in the drum vs brake trailing arms could be something as simple as different brackets for brake lines and holes for dust shields? I don’t know for sure… just guessing.
Although… according to KingMotorsports the crx and civic TA bushings have different part numbers… hmm And going purely by part number the crx, DC2, and 92-2000 civics all use the same TA bushing… which is different from the 88-91 civic bushing.
and the 90-91 CRX Si came with rear disc…
actually the 90-91 CRX si’s have the same p# rear pad, caliper, rotor, hose brackets, metal mud guards, and those skinny little dust shields… 
p.s.
I spent SOME time comparing rear susp. numbers this mornin.
I guess it’s about time that I get involved with all this.
I’m the guy that wrote the original page on installing the “Mugen” bushings within the integra bushing shells.
It was REAL weird calling a “local” Honda dealer and having Scott pick up the phone (and make the connection as to who was who).
I’d like to clear up a bunch of items that are part of this 10 page string.
The subject of the Mugen bushings being 120% stiffer than the Honda bushings was the result of what I was told when I talked to King Motorsport. Although it’s possible to interpret this two different ways, when I talked to the people at King, after having the new OEM bushings in my hand, the subject was clearly worded such that they presented them as more than twice as stiff. All of my comments about this are this are in regards to what Honda is currently selling and NOT what may have been the original design.
As I understand it, the 90/91 CRX SI trailing arms are the same as the Integra arms. This does NOT include the 90/91 Hatchbacks. It would appear to be a function of if the car has rear disk brakes or not. Of the two arms that I got from a junk yard to convert to rear disks (on my 89 Civic Si), one is a CRX Si (on the drivers side) and the other is from an Integra. Both required that I do the “bushing shim” trick to install the bushings that I had.
Now that it appears that it’s possible to purchase the correct sized bushing from Honda (Accura), it’s questionable if the shim trick has any purpose at all. What I’d like to know is if the Integra bushing is any stiffer (or less stiff) than the Honda unit.
Figuring the “angle” that the bushing should be installed is easy! With the car sitting on it’s wheels, it’s possible to place a straight edge on the flange bracket (where it bolts on the frame rail) and see where it points. The longer the straight edge the better. When you install the new bushings, you want the flange pointing in the same direction. This will result in no “preload” to the bushing when installed and back on the wheels.
Wes Vann
There’s never been an issue to find the true vertical, the question was… perhaps a level of preload, either negative or positive, maybe ideal(or at least tune the bushing by turning/loading it). also, we have looked at both OEM and Mugen bushings… I know some are convinced of there durometer being higher… I can’t see it. If it is in fact higher, I would think I 120% is more like the amount(20 percent stiffer)
It’s my opinion (ya, everybody has one) that Honda intended the bushing to have no preload (twist). I can see how angling the bushing “web” (the sections that go up and down) could help with limiting movement along the cars center axis. However it would tend to cause the bushing to wear out faster.
One solution would be to go to an alignment supply store and get some alignment wedges (I don’t know the correct term but they are for phasing a solid rear-ends axle assembly). Then you could install the bushings at an angle and have the wedges between the bushing flange and car’s frame rail. This would result in the bushing not having a constant “twist”.
I wouldn’t do it, but the idea is there for any who want to try.
Wes Vann
Yeah, it is probably more work than it is worh, but the theory of rotating the bushing is sound. we would need several of them at varying rotations and test them back to back on a track to get true feedback. And on top of it all, the degree would probably be different at each track you went to…
If this is true, then King’s website must be wrong. The website lists the Mugen Bushing, part number: 52385-XE9-S0N0, as being for all 88-91 CRX’s. So, something has to be wrong…unless the DA and 90-91 crx si trailing arms are the exact same, and the 88-89 are similar, but all 3 have the same size bushing…which would go against all the previous info posted here
Scott, I know that the 90-91’s came with disks… the reason I said what I did was that the bushings are sold for all “88-91” which includes the 88 and 89 which did not yet have disk brakes. And if the 90-91’s used the same bushings as the integra… blah blah blah, maybe I just got confused with what you said? When you said the crx and da “ones” could possibly be the same were you referring to the bushing? or the whole arm?
man, i’m starting to confuse myself :uhoh:
man… reading that made it confusing for me. that’s why i went with DC arms, SPC LCA’s, SPC camber and toe adjusters and just called it a day. and 10yrs from now if i ever need to change the TA bushings i have Mugen ones that will bolt in with no shimming needed.
Colin, I understand, and that would be out of whack if they say that its the same number… I’m not sure aboot the aftermarket stuff. especially considering my Prothanes are at home and may NEVER be installed, especially if I could just throw these in without regret. :rockon:
Wes V, nice talkin to ya,
hopefully you’ll be around more to put in your 2 cents on lots of issues, take care.
What the heck are you guys talking about
Differences with the bush/trailing arms between 91-crx w/ rear disc and the da’s .
:read:
longest GD thread ever. 
And its all mine! :inlove:
Btw, there was no 88 civic si.
Ben
Some of the confusion may be due to Honda not always considering a CRX a Civic.
Wes
I’m just still wondering how the mugen bushings could fit all 88-91 crx’s (which is a different bushing part # from the 88-91 civic) and the 90-91 crx si arms are the same as the da arms… yet there is no mugen bushing that is a direct fit in the da arm. Something here is fishy, too much of the info is contradictory.
Ben, did the si start in 89 for the civic? I know they did make 88 crx si’s.
Robbie, you’re such a whore! 
Let’s see some pics mang. You’ve got my curiousity at an all time high.
~B
Heh, I just noticed that the west coast has monopolized this thread.