M3 Castor Bushes

[poolnoodle]

Hi All,
The chromie needs new castor bushes and I have read all about the benefits of M3 eccentric type. I can get a OEM pair for less that US$50 from Pelican.
My local BMW Autohaus is going to fit them for me - any dramas to expect?
Will they fit ALL e30s?
Will I need a wheel alignment once fitted?
TIA

Neal

[mark_i]

Hi Neal

the offset bushes work with all e30... i got them on my touring and 2-door.
both feel so much better in terms of precise steering.

[daimlerman]

Make sure that they line the bush up correctly with it's housing,the aim is to move the base of the wheel out and a little forward.

Yes,have the tracking checked and adjusted as required.

You may also need to adjust the fit of the front plastic underpanel to stop the tyres catching on full lock as well.

Advantages are noticable,I ran two E30's side by side once,one with eccentric front bushes and one with concentric,even 'er indoors noticed that the eccentric fitted car 'steered better'....

[poolnoodle]

Thanks guys - sounds like the way to go

[Alex]

Only downside is that on full lock the tyre will rub on the inner arch plastic splash guard slightly.

Not sure if it would do the same on a pre facelift

[Demlotcrew]

Make sure that they line the bush up correctly with it's housing,the aim is to move the base of the wheel out and a little forward.

Yes,have the tracking checked and adjusted as required.

You may also need to adjust the fit of the front plastic underpanel to stop the tyres catching on full lock as well.

Advantages are noticable,I ran two E30's side by side once,one with eccentric front bushes and one with concentric,even 'er indoors noticed that the eccentric fitted car 'steered better'....

They wont move the base out or alter the track width only castor angle.

[steve_k]

Demlot, what would the effect on the handling be if you were to use the m3 eccentric bushes with the offset top mounts??

I only ask as I am looking at using both of these.

OP sorry for the hijack.

[Demlotcrew]

Bushes cause castor change, top mounts cause camber change, it really does depend on what you are trying to achieve, for a track car both will only result in better handling

Dont forget, the amount of -ve camber thats needed is totally proportional to the roll of the car. What that means is, if you have a boat then no top mount I know off will neutralise the effects.

Andrew

[steve_k]

Well i'm aiming for a cross between a road car (mainly) & a track car.

i'm going back to using coilovers (F & R) in the new year & i'm currently using a 24mm fr ARB & A 18mm r ARB.

I ain't interested in outright topspeed just want a car that handles the best it can.

[Demlotcrew]

I would not advise you run large -ve camber settings on the front, you don't want to loose front end grip on the road (even though underteer is easier to correct than oversteer) during hard braking. Just set the car up for road and enjoy it on track. You cant have both sadly.

Andrew

[steve_k]

No worries Andrew thanks for the advise

[steve_k]

I would not advise you run large -ve camber settings on the front, you don't want to loose front end grip on the road (even though underteer is easier to correct than oversteer) during hard braking. Just set the car up for road and enjoy it on track. You cant have both sadly.

Andrew

well i took your advise (in a way) & have now got a set of m3 eccentric bushes & also refitted my eibach adjustable top mounts,

at least now when/if i take it to a track day i can set it up for -ve camber for handling & when i've finished i can set the front end back to standard camber for the drive home.

[capri_rob]

Only downside is that on full lock the tyre will rub on the inner arch plastic splash guard slightly.

Not sure if it would do the same on a pre facelift

The splashguards are adjustable - on max adjustment no rubbing

[poolnoodle]

Having the bushes fitted tomorrow and wondering what is involved here:

You may also need to adjust the fit of the front plastic underpanel to stop the tyres catching on full lock as well

The car runs 16x7.5" wheels, lowered on Eibach Pro Kit

[daimlerman]

If you examine the plastic panel's mounts,you will see that they are mounted by those black plastic 10mm nuts onto welded studs.The plastic panels all have slots instead of holes to allow for adjustment...so slacken off and pull 'em about until the wheels clear the panels on full lock.

The tyres rubbing on the plastic bits is not a problem for MoT in the UK,no idea if you lot who walk on your heads will have an issue,though!

[poolnoodle]

No MoT inspection around these parts - pay the fee you get to drive it so long as the boys in blue don't catch you

Hopefully get the car back today so will take a closer look.

[HairyScreech]

Your ride height will have an effect on how much static camber you need as well, as the angle of the lower wishbone is important, it dictates the camber change in roll and bump.

For an e30 around 30-40mm drop from standard height (not mtech) around -1.5 to -2.5 degrees seems to be a good point to aim for on the front for general day to day depravity and some fast work, seems pretty livable for both if you stick around there.
Seems to be true for the e36 compacts as well.

40mm drop with eccentric bushes gives about -2 to -2.5 front camber and a few degrees extra castor, tyre wear is reasonable, grip is reasonable and feedback is excellent.

One thing to remember is track days are not timed races, its far better to have something half a second slower on track that is more fun and easier to drive than something set up for ultimate grip that snatchy and uncomfortable.

[poolnoodle]

M3 bushes now fitted and makes a nice improvement - particular higher speed / sweeping corners. Car feels more planted and steering more responsive.
Have noted that low speed (ie parking, etc) is slightly heavier. Is this normal?
Had no issue with tyres rubbing inner guards.

[HairyScreech]

Normal on all 3 accounts, some cars catch some don't, I think its down to splash guard adjustment and e30 vs e36 rack.