Inside tire wear

[e34john]

All 4 tires are wearing on the inside. I know I need to to align the front, but what do I do about the back? Is the only thing just to keep up on the rotations so it wears as evenly as possible? I have 225/45 16s on a 60/40 kit.

[erik325i]

Do an allignment, keep your tire pressures up, and rotate your tires on a regular basis.

There are kits to make the rear end more adjustible if you wanted that.

[e34john]

Yea, I need to ge the alignment done before I get new tires. Maybe I don't have enough weight in the back. No tar or spare, I think I will keep the gastank full more often.

[StereoInstaller1]

Change the rear trailing arm bushings to Urethane, it will help keep geometry straight and you will get WAY better life from the tires.

[george graves]

Change the rear trailing arm bushings to Urethane, it will help keep geometry straight and you will get WAY better life from the tires.

Is this right? Well, if so I guess I'll do urethane after all.

[e34john]

Change the rear trailing arm bushings to Urethane, it will help keep geometry straight and you will get WAY better life from the tires.

Have a link to this magical bushing?

[StereoInstaller1]

I have IE, but there are several on the market.

I am not talking about adjustable ones, just basic Urethane.

[Philo]

A new rubber bushing will do just as well as a poly bushing IMO, just not be as rough. What Erik said is the most helpful though; tire pressure, rotation, alignment. As for your weight theory, adding more weight would create more camber, thus, increasing the inner tire wear. This is not what you want.

[erik325i]

Is this right? Well, if so I guess I'll do urethane after all.

A new stock rubber bushing will do the same thing. The point is that new bushings (of any material) are better than worn out stock bushings with 200k miles.

Maybe I don't have enough weight in the back. No tar or spare, I think I will keep the gastank full more often.

You have it backwards. More weight will cause the car to sit lower and get more negative camber.

Erik

[Philo]

Echo. . . echo . . echo. :D

[StereoInstaller1]

A new rubber bushing will do just as well as a poly bushing IMO, just not be as rough.

I will disagree here completely.

Rubber bushings are far less stiff than rubber...duh, right? The point of this is that the rubber deflects dynamically, as in under load, with an "angle" in that the camber or toe will be multiplied as the bushing goes through its travel, where the urethane, while still able to deform, will exhibit less distortion, thus retaining more of the original static measurement.

In other words: rubber still deforms more than urethane, even when it is new.

This is why they cause better tire wear: they hold the pivot point accurately and deflect far far less than rubber.

Of course, fresh rubber will be better than shitty old 200,000 mile rubber.

As far as NVH, I have well over 300,000 miles on cars with no rubber bushings at all, and I am a grumpy old bastard that needs a nice smooth ride. Yes, no doubt that rubber is a nicer ride, but the urethane feels so much smoother on "turn in", and as the corner progresses, just feels more "planted" and is thus worth the tiny little bit of asphalt you feel.

Up front, the improvement in braking even over the solid M3 control arm bushings makes urethane the only choice in my book.

And before any of you guys spout the old "have you felt how new rubber feels" remember, kids....I drove the piss out of these cars when the whole damn car was new!

My opinion is this: if your car is a daily driver on lowering springs, use urethane for control arms and trailing arms, but all rubber on everything else.

YMMV.
Luke

[e34john]

You guys are right about the weight in the back, I just thought about it and the mental picture I had before was wrong.

Saw the urethane kit 50 bucks or so, not bad, maybe I'll get the rear camber kit too, gonna think about it.

[E30Idea]

Get an adjustable kit fron dungeon motorsports. That is what I did and my car is matching 2 degrees front and rear camber and 0 tow all the way around.

[george graves]

^Will any guy that's been to alignment school be able to jump right in and set up the car with those eccentric bolts? Or do you need to take it to someone with experience with it? Or the right rig?

Those are kinda standard part's aren't they?

[E30Idea]

^Will any guy that's been to alignment school be able to jump right in and set up the car with those eccentric bolts? Or do you need to take it to someone with experience with it? Or the right rig?

Those are kinda standard part's aren't they?

they are stock E36 parts I believe. Simple weld in tabs, bolts and nuts. there is really nothig to it. took dashboardMonkey and I about 4 hours to get the subframe out, RTA off, tabs welded on and reinstalled. The alignment shop new exactly what I installed when I took it to them and explained and they had it done in 45 minutes.

My race the next weekend yeilded an easy 30% more traction because I have almost 40% more tire on the ground. I went from 4.6 degrees negative camber to my requested 2.0. Easy best bang for your bucks item to be added to the e30 to do list.

For what its worth you can get the Hardware online or forom BMW directly.

- Eccentric Bolts, Eccentric Washers and Lock Nuts through Pelican Parts:

You will need 4 of each if you are doing both camber and tow. Otherwise you will only need 2 of each.

BMW Part # - 33321095102 - Eccentric Bolt
BMW Part # - 33321092310 - Eccentric Flat Washer
BMW Part # - 33326760668 - Self-Locking Collar Nut

Here is the diagram from the parts off realoem

http://www.realoem.com/bmw/showparts...33&fg=30&hl=31


Honestly, I would just support Dungeon and buy there kit. Comes withing a few days and you get everything you need.
Here is there link on e30tech. This is where I ordered:

http://www.e30tech.com/forum/showthread.php?t=80410