It has a arb as standard, not sure I'd want to stiffen that on the rear though.
On a related note, I had to change the rear anti-roll bar on my 156 when I fitted the sensor for HID headlights. The bar is a cute and spindly little thing, 10 or 12mm I think it was. With it fitted, and the rear of the car on axle stands, both wheels were hanging free. I placed a jack under the hub carrier of one wheel, and jacked up until the suspension for that wheel was almost fully compressed. The suspension on the other side didn't lift the wheel by any measurable amount! Therefore, I suspect that the standard anti roll bar on the 156 is likely to have no effect on the handling, as it is too weak to overcome the unloaded suspension, never mind when the springs are compressed - so, how would there be any weight transfer? The bar can be twisted by hand! I wondered why it would be fitted at all, and then I saw two good reasons:
- it's a convenient point to attach the level sensor for the headlights
- it's a desirable item to have on the specification for a car
This decorative purpose might also explain the use of plastic drop links. Remember this is a car with 'BOSE' stuck to an empty tweeter grille
The Ultra Racing bar for the GTV/Spider is 20mm. That sounds more useful - so, has anyone found a difference with it fitted in place of the original? I'll assume the original actually does something on the GTV/Spider!