powerflex bushes

Sat Jul 09, 2011 9:04 am

hello i own a 1990 318is dose any one know what size i should order and if they are concentric or eccentric type
thanks

Sat Jul 09, 2011 9:28 am

Eccentric were designed for M3's where a little more caster angle was required to stabilize the car at high speed. Later M3's had different geometry and didn't require the offset bushes. Unless you intend on racing your car standard concentric ones are the way to go.

Sat Jul 09, 2011 10:05 am

lemmy99 wrote:Eccentric were designed for M3's where a little more caster angle was required to stabilize the car at high speed. Later M3's had different geometry and didn't require the offset bushes. Unless you intend on racing your car standard concentric ones are the way to go.

Don't think there's many on here who would agree with the above. The general consensus is that the increased castor from eccentric bushes is an improvement on any E30.
What I would advise against is your choice of plastic aftermarket stuff rather than genuine BMW.

Sat Jul 09, 2011 7:07 pm

I ran two E30's side by side for a while,one with concentric bushes,one with eccentric bushes,even my wife commented that the one with eccentric's 'went round corners better'.....

Unlike Brian,I am a fan of poly bushes,they transmit noise into the car,but wear very well.

Sun Jul 10, 2011 5:06 pm

Increasing the castor angle, weights the steering and increases amount of self centering (hence the need for it on the M3), while this might not be so noticeable with power steering, it would be with keep-fit steering.

I ran two E30's side by side for a while,one with concentric bushes,one with eccentric bushes,even my wife commented that the one with eccentric's 'went round corners better'.....

While I don't disagree with this statement, there is no telling that the car fitted with the concentric bushes didn't have another issue, worn shocks for example, that may have made it feel worse to drive. You would have to do a back-to-back test on the same car.

If Brian feels that increased castor is of benefit over the standard angles, then i bow to his greater knowledge. The argument for and against poly/rubber will be down to personal taste (I'm in the poly camp)

One thing i would note, is that poly eccentric poly bushes rely on stiction to keep them in the correct orientation between the poly and the lollypop, rubber bushes are bonded into the metal sleeve and this is an interface fit in the lollipop and unlikely to twist out of position.