Sway Bar again! Will an M5 sway bar fit a 540i?

[leicesterboy15]

HI All

I've done a search but can't find what I need. What I want to know is will M5 sway bars fit a 540i touring? Are the fittings the same for all sway bars and for the saloon / touring? I guess they will be at the front.

Is it worth swapping my standard ones for second hand M5 ones? If I install only the front will that make a difference? Do they deteriorate or loose their shape / rigidity over time? Is the M5 one going to provide better handling?

I can't see how one metal bar can make such a difference to the handling to a slightly bigger / smaller metal bar?!!!!!! So I guess I'm not best placed to answer these questions!

Are thicker sway bars more rigid and there for provide less wheel camber when turning or am I talking utter bollox?

[EngPhys09]

HI All

I've done a search but can't find what I need. What I want to know is will M5 sway bars fit a 540i touring? Are the fittings the same for all sway bars and for the saloon / touring? I guess they will be at the front.

Is it worth swapping my standard ones for second hand M5 ones? If I install only the front will that make a difference? Do they deteriorate or loose their shape / rigidity over time? Is the M5 one going to provide better handling?

I can't see how one metal bar can make such a difference to the handling to a slightly bigger / smaller metal bar?!!!!!! So I guess I'm not best placed to answer these questions!

Are thicker sway bars more rigid and there for provide less wheel camber when turning or am I talking utter bollox?

The bars will never lose their shape you will just wear out your bushings. I just did a big write up on what I plan to do. I've come to the decision that i'm getting RD bars to go on my car instead of M5. You likely will not notice too much of a difference from yours to an M5 bar.

Its more then just bigger or smaller bars. It has a lot to do with the shape of the bar. They are essentially a big spring that push on the wheels to stop them from moving inwards "chamber change" when cornering.

In general thicker bars are stiffer but it depends a lot on the material the bars are made up of. Are they hollow or solid bar etc.
I had to do a lot of research and contacted John at Racing Dynamic USA to figure out what I should do.

[Jan]

My 540i touring was born with same size sway bars as the m5.

[leicesterboy15]

Thanks for the info guys.

My 540i touring was born with same size sway bars as the m5.

So I guess mine was as well, this is what I suspected.

I suppose the conclusion then is that its not really worth it as its not really an upgrade?

[neil_004]

Real oem says they are the same size. There was a 20mm sway bar for the rear. Might be overkill.

Here is a link to how diameter of the bar affects it's stiffness.
http://www.kormanautoworks.com/tantiswa.htm
Basically a 1mm increase will provide you with a 24% stiffer bar.
A 2mm increase will provide a 52% stiffer bar.