Three chassis mounting points, one for the top camber control link, two for the trailing arm.

Three upright mounting points, one for the top camber control link, two for the trailing arm.

With the Porsche 928 IRS, the lower trailing arm reacts longitudinal and lateral loads largely in bending. The lower lateral link reacts only camber control loads, and contributes virtually nothing to the longitudinal and toe loads. The upper camber control link controls the front view instant centre. The side view instant centre is controlled solely by the lower member.

There is no allowance for the articulation of the Porsche 928 trailing arm chassis pivot.