Sway-bar size...?

[blue2000s]

Originally Posted by John V

Remember that while the M030 "S" bar is 24mm, it's also hollow. The 24mm Eibach bar is SOLID! Big difference in stiffness.

Front bars:
986 non-s standard suspension 23.1mm diameter 3.4mm wall thickness
986 non-s M030 suspension 23.6mm diameter 3.5mm wall thickness
986 S standard suspension 23.6mm diameter 3.5mm wall thickness
986 S M030 suspension 24.0mm diameter 3.8mm wall thickness
996 GT3 Bar 26.7mm diameter hollow
Eibach bar 24mm solid

Rear bars:

986 non-s standard suspension 18.5mm diameter 2.5mm wall thickness
986 non-s M030 suspension 19.6mm diameter 2.5mm wall thickness
986 S standard suspension 18.5mm diameter 2.6mm wall thickness
986 S M030 suspension 19.0mm diameter 2.7mm wall thickness

Yes the non-S M030 rear bar is the stiffest.

The solid bar will deflect about 28% less for a given torque than the hollow one. But I wonder if you'd notice that difference if the car is barely leaning with the hollow bar.

So the solid bar would be a 1.549 on this chart:

http://www.cb-racing.com/boxster_030.html