Offset Bushings

#1

So the bushing have given up the ghost sometime in the last 165K miles.

Given that I would like to adjust my rear toe and camber, it sems that offset/accentric bushings are the way to go.

It would seem to be a good idea to use them for the front control arms.

The question:

I keep looking at these bushings, but cannot see how I would turn them to adjust the suspension, and if I could turn them, I can’t see how I would lock them in place.

I would love to just install these see pic for toe and camber,
but question their legality.

So a couple of questions for the group:

  1. How do you adjust the accentric bushings?
  2. Can I install these and call it a day?
#2

Ben,
That looks like a "weld-in" kit, which is illegal per Spec E30 rules.

I think most of us run offset bushings (bimmerworld, and others sell these for about $200). The offset is what allows you change camber and toe. Unfortunately, due to the semi-trailing arm design, when you adjust one, you adjust the other, so it’s a bit of a pain to get right. Once you set it, you can forget it thought.

There’s really good info on this here:
http://www.e30m3performance.com/tech_articles/susp-tech/ecc_bush/ecc_bush.htm

Good luck!
-Vic
So #325

#3

great article!

edit:I just found the k-mac site and finally found a picture that shows the adjustment, now I get it. Very different from the akgmotorsports bushings I was looking at.

Thanks, k-mac for me.

now to try and find them on bimmerworld, that seems to only be showing powerflex.
Ben

Post edited by: thresholdBen, at: 2006/05/30 11:51

#4

We no longer sell an adjustable rear trailing arm bushing. The company that made these went out of business and we have not found a suitable replacement as of yet that we feel comfortable selling.

Adjustable Tabs are vastly superior in terms of being user friendly. The adjustment range is roughly the same as an adjustable bushing. I have used 3 different eccentric bushings in my E30s. Stock which are soft and non adjustable and are very tough to get placed properly. The old ones we used to sell which were functional and stayed tight(not all of them do so I hear) but were difficult to adjust do to the very high torque you had to put on the bolt to keep them tight. And I’ve used tabs which while labor intensive to install are by far my favorite. Traditionally this has been the best way to get adjustment in the rear of these cars.

#5

tabs?

#6

Yeah… tabs?

#7

What’s the consensus on the Delrin Bushings that turner sells? The aren’t adjustable but it seems like they may be plenty stiff. The people building new cars seem to be at a disadvantage since there are no real legal adjustable rear trailing arm bushings out there.

#8

I talked with this guy the other day, and he reccomended the hard poly bushings instead of the delrin.
You get the same hardness without the britle-ness.
Absolutely hysterical to talk with on the phone, but he doesn’t do orders, just technical talks.
Orders should be done through the website.
Might be good wholesale source for bimmerworld.

From his comments, I am pretty sure he is making the delrin bushings at Turner.

http://www.akgmotorsport.com/e30products.html

Post edited by: thresholdBen, at: 2006/06/01 10:09

#9

Nice find, those acentric rear trailing arm bushings look like the ticket. He makes some good lookings stuff.

Post edited by: dmoses, at: 2006/06/01 10:56

#10

I have some on order, they are in the process of machining them (were not in stock), I can snap some pictures of them when they come in, or you can email them and ask if they can build yours while they build mine.

I also got the offset front bushing done in poly, not listed on the website, but an email was all it took.

PS I am still curious what a Tab does for rear alignment.

Post edited by: thresholdBen, at: 2006/06/01 12:10

#11

As it was observed earlier in the thread, adjustable bushings are not, at least currently, available so people who are building cars now (and maybe in the future) are ‘doo-doo’ out of luck.
What would be consensus if we are allowed to do something like this:

http://www.e30m3performance.com/installs/installs-3/jl_sub/index.htm

I do realize that it’s weld on, however the solution would be in "the spirit of the rules" of having adjustability.

Carter, what would be ruling on legality of this?

Regards,
Igor

[ul]not trying to change rules[/ul] , just figuring out which direction to go and which parts to buy…

#12

I ordered a bunch of stuff from AKG this morning including there accentric rear trailing arm bushings. We’ll see how that turns out.

#13

All of my akg bushings including the rear eccentrics showed up last week, I took pictures of them all and will post them tonight.

Are there any particular views of the bushings people would like to see?

Post edited by: thresholdBen, at: 2006/06/09 08:00

#14

Several of us have the KMac rear adjustable bushings. Are they not available?

#15

I couldn’t find any kmac for the e30 availible anywhere.
That doesn’t mean they aren’t out there, just that I couldn’t find em.

Of course, I can’t find my stupid camera cable to upload the akg pictures either, so I may not be the best source.

Ben

#16

How many people are interested in the Bimmerworld-style adjustable trailing arm bushings? I sent Rob an email that I’d be interested in machining them for BW. They would be copies of what they were selling before his supplier went away.

#17

thresholdBen wrote:

[quote]All of my akg bushings including the rear eccentrics showed up last week, I took pictures of them all and will post them tonight.

Are there any particular views of the bushings people would like to see?[/quote]

Ben,
did you get these bushings? If so are they adjustable?

I also looked for KMAC adj bushings but can’t find them - will keep looking.

However I would also like a ruling on the "weld on kit" because I would like to know if I should keep it in consideration or not. :whistle:

Igor

#18

Those are what I got, they are adjustable.
If you want, I will do a detail assembly level set of pictures for you.

#19

With all this talk about adjustable rtabs, I was wondering what sort of alignment settings you guys are / were getting with non-adjustable rtabs, and what you’re setting the alignment to with the adjustable rtabs? My rear is at -2.5(L), -2.7® camber, very slight toe-in with the stock bushings, which would seem like a pretty reasonable target.

I’m planning on installing delrin subframe bushings and rtabs to keep things from moving around (the rear lets go before the front does, and I have some issues getting power down coming out of corners - I’m hoping this will help with this problem). I’m assuming (yes, I know that’s dangerous!) that the alignment will not change much with the new bushings. Before I undertake this, though, I thought I’d see if anyone had any thoughts on whether I should wait to try and find adjustable rtabs or just go with what I’ve already ordered? From the looks of it, this is a large project that I’d rather not do more than once!

Not to shamelessly ask for "racer secrets" re alignment, but I thought I’d throw out the question for suggestions. Thanks in advance!

Steve

#20

Steve, your rear end numbers look great. I wish that my fixed K Stock car was so well balanced. I wish that my adjustable Spec e30 car was so well balanced. Like you, I would hope that they do not change withthe addition of the sub-frame bushings.Consider yourself lucky and leave the stock bushings alone. Regards, Robert Patton