Wear on rear tyres?

[DanTheMannn]

Right,

straight to the point here!

Been drifting here and there, Rear tyres are only wearing on the inner bits of the tyre.

Obviously on the front i'd think alignment? but rear? i didn't think you could adjust rears no steering arm?

(or would you adjust front to counter rears?) I'm confused..


What is causing this? (i hear over inflating tyres can also cause this but they're at a soft 35 each)

Ideas?

[Nobby_N]

I think the main reason there fooked is the way your drifting it, you got to be smooth! What engine u running any pics, any ink?

[DanTheMannn]

2.5 m20,

Also doing plain and simple burnouts you can clearly see inner tyre wear is much more than the outer.

[Grrrmachine]

have you lowered it in any way?

Besides the damage of doing doughnuts, you may have a problem with your camber or toe. Too much negative of either will cause scrubbing and feathering on the rear tyres, leading to inner tyre wear.

You can measure camber with two bits of wood and a spirit level; measure tow with a bit of string tied all around the car.

If you find you've got a problem, it'll be expensive to sort - there's no adjustment at the back end of an E30.

[DanTheMannn]

Yeah i was also thinking camber but thought i may be able to correct with Camber plates?

Reckon we're onto something?

[Silverfang]

IF the car's been lowered, then the inside edges will wear moreso cause you've dialed in more camber angle, great for cornering but not so good for the inner edges.

2 options, either is to raise the car some, or get a subframe and have camber plates installed, then swap over.

[DanTheMannn]

Car hasn't been lowered, all original suspension (soon to be changed at the end of this month with coilovers)

So this is going to take a lot of head scratching i see!

[Silverfang]

Huh, could be worn trailing arm bushes then, or subframe bushings. Either way best to get those checked over before installing the coilovers or it could make the problem worse.

[verde]

Its camber wear.

BMWs have insane rear camber, when the suspension is loaded and the car drops the camber is very noticeable. When youve booted it into a bend and thrown all the weight sideways at full gas youve compressed the rear suspension abnormally and thats what happens. If you lower it in any way the the camber will obviously be more permanent. Helps with handling but you will wear the inner tyres out.
My E21 has savage camber wear and it rarely gets broken loose

[Grrrmachine]

Its camber wear.

Only if the suspension is fucked.

E30 rear trailing arms only have a sweep of 15 degrees, and the camber should be set between -1.3 and -2.3 degrees. The whole idea of the semi-trailing design is that, as the wheel deflects during body-roll or wheel bounce, the wheels will not only lift but arc their camber to compensate, as well as increase the toe-in to improve auto-straightening. There's nothing abnormal about it - it's an incredibly clever design.

If you're getting to the point where your inners scrub then you're either throwing the car sideways at every corner, or somethings fooked with your suspension.

[Motorhole]

Sh*gged springs/dampers and/or trailing arm/subframe bushes would've thought.

[verde]

Its camber wear.

Only if the suspension is ******.

E30 rear trailing arms only have a sweep of 15 degrees, and the camber should be set between -1.3 and -2.3 degrees. The whole idea of the semi-trailing design is that, as the wheel deflects during body-roll or wheel bounce, the wheels will not only lift but arc their camber to compensate, as well as increase the toe-in to improve auto-straightening. There's nothing abnormal about it - it's an incredibly clever design.

If you're getting to the point where your inners scrub then you're either throwing the car sideways at every corner, or somethings fooked with your suspension.

He admitted to throwing the car sideways and drifting it, and in doing so on standard suspension then it may well be absolutely shagged.

Even tyre wear is for pussies anyway

[DanTheMannn]

Damn right!

Ok, so ill check bushes before i lower the badboy and probably replace even if they look ok.

We'll see the outcome soon enough!

[polsta]

Also what tyres ??

I had a car on 17bk reps and 60 mmm drop springs, and rear inner edges of brand new tyres , were showing nylon !!

[TPS]

Had my tyres changed today, my rears are wearing on the inside as well. I don't think its lowered, anyone know how I can tell? Its a Touring

[Speedtouch]

The OEM springs are black, whereas most aftermarket ones are fancy colours, Eibachs aside.

Get a pic of the side view so that other Touring owners can tell you if it's lowered or not, though from your signature pic, I would hazard a guess not.

[TPS]

They're Black, I'd be amazed if its Lowered, the Beam bushes need doing, (which'll be done in the next few weeks), I don't know if that would cause this problem.

[DanThe]

This is what you need-

[Grrrmachine]

It's well worth checking the Camber and Toe at the back end of the car. I was getting massive inner tyre wear and found out I was 5mm toe out at the back. One of Dan's kits sorted me out

[ROC]

How much adjustment do you get with Dan's plate kit? Does anyone have a write up of how they are fitted please.

[Grrrmachine]

According to the Yanks, if you position the tabs so that the existing holes are in the centre, then you'll get 0.6 degrees of movement either way. Conversely, put the hole at one end and you'll get 1.2 degrees of movement in one direction.

[ROC]

Thanks Grrrmachine, I ask as am part way through a track car build going on coilovers.

The rear subframe is off at the minute, is it worth fitting the tabs?

[maxfield]

Thanks Grrrmachine, I ask as am part way through a track car build going on coilovers.

The rear subframe is off at the minute, is it worth fitting the tabs?

Yes.

[TPS]

This is what you need-

What, new Trailing Arm Bushes?

[Grrrmachine]

If you look at that rear beam it's had the holes for the trailing arm "slotted", and those bolts are eccentric - the shaft doesn't go through the middle of the head. That way, as you rotate the bolt, you can push or pull that side of the trailing arm in or out. The inner mounting points set camber, the outers set toe.

I'm working on this Wiki page at the moment, if that helps:

http://www.e30zone.net/e30zonewiki/inde ... d#Geometry