Anyone using Z3 rear trailing arms?

[EVOIIIM3]

Do the stock E30 brakes still fit? What about wheels?

I want the reinforced trailing arms, but I'm not to into having to get new brakes and wheels for it.

My room mate has a M Roadster, if he lets me I might try and fit the E30 brakes on it.

[Derek 357i]

I am using the M Roadster trailing arms on my standard body e30. It will change your rear offset requirements to more e36ish.

I think if all you are looking for is reinforcement, I would probably have the ones on your car reworked. I would use full box tubing as opposed to c-channel. Same with the small triangular gusset which prevents dynamic camber gain. I would think just about any machine shop could do that for you in very little time.

[AdamF 88iS]

Either way you have to pull your own arms out, so you may as well just get yours done. There is no advantage to the hassle of figuring out the brakes and whatnot plus the cost of buying the M roadster arms in the first place.

[Mmark]

Originally posted by Derek 357i
I am using the M Roadster trailing arms on my standard body e30. It will change your rear offset requirements to more e36ish.

They have a different "trail" angle than the E30M arms. the same goes for the non M e30 machines.

Just have your originals gusseted like the MZ"s
m.

[Derek 357i]

Originally posted by Mmark
They have a different "trail" angle than the E30M arms. the same goes for the non M e30 machines.

Just have your originals gusseted like the MZ"s
m.

I am not sure what you mean by different trail angle. Can you elaborate?

[Mmark]

I'm thinking from comparison pictures I have seen, that the MZ arms are shaped more like an "A" as compared the the "V of the E30M. the angle in the fork looks different to me. (ignoring the cross brace on the latter model arm.)
I think this may result in a change in the geometry in the rear, possibly more static negative camber at ride height and a camber curve that would be biased toward less positive camber gain with suspension movement.
I have not had the opportunity to compare, the camber curves of each arm as it moves thru its arc of travel.
jmo.
m.

[Stan]

Look over at Gustave's site...he discusses and shows photos of E30 M3 and M-Coupe/Roadster trailing arms, modified and braced arms, camber/toe adjustable subframes and so forth. The suspension pickup points and angles and so forth of the later arms matches ours but things like the braking accomodations are different. Nice brace between the arms, stronger hub vicinity. Nice mod for those vette powered E30s. Or the six-it crowd.

www.e30m3performance.com

Stan

[jimmy p.]

Originally posted by Mmark
They have a different "trail" angle than the E30M arms. the same goes for the non M e30 machines.

Is that for sure that standard E30 trailing arms?
I was always under the impression the "Arm" was the same. Just the hub different.

Are you sure about that?
I dont have my ETK out here, so I cant check the part numbers.

Thanks
jimmy

[elcortez]

The rear trailingarm for the complete e30 series including the M3 is: 33 32 1 137 641

For the M-roadster 1,9 - 3,0 is: 33 32 1 094 761

For the MZ-Roadster: the number is: 33 32 2 221 967

[EVOIIIM3]

Originally posted by Derek 357i
I am not sure what you mean by different trail angle. Can you elaborate?

I have one M-coupe arm, and I just ordered new E30 M3 arms, we will see how they are different in angles and size.

[Derek 357i]

Nice work, I'll be curious to see the difference. Are you going to weld the reinforcements on the new arms? If so, what are you going to use? When I was considering doing this, I was kicking around .125" wall 1"X2" box tubing. I was also going to use .1875" for the gusset that reinforces the upright portion. Then I got the M Roadster suspension, so I never took it any further.

[EVOIIIM3]

Originally posted by Derek 357i
Nice work, I'll be curious to see the difference. Are you going to weld the reinforcements on the new arms? If so, what are you going to use? When I was considering doing this, I was kicking around .125" wall 1"X2" box tubing. I was also going to use .1875" for the gusset that reinforces the upright portion. Then I got the M Roadster suspension, so I never took it any further.

You have them in your car now?

Not sure what we are going to use, it's going to come down to time & money. It might be mild steel, or just some box tubing welded on.

I'm going to the M-coupe arms to show the welders what needs to go where.

[Derek 357i]

Yes, they are on the back of my e30 non-M.

[EVOIIIM3]

Originally posted by Derek 357i
Yes, they are on the back of my e30 non-M.

And you have no input with my questions?

No worries, I got new E30 trailing arms and the reinforcements are being welded right now.

[Derek 357i]

Originally posted by EVOIIIM3
And you have no input with my questions?

No worries, I got new E30 trailing arms and the reinforcements are being welded right now.

I answered above that they would change your offset to a more e36ish offset. I had 318i drum trailing arms, so I didn't have anything to compare them to. I would be glad to answer any questions you have regarding them.

D