In the attached wire DOP sim any ideas how to stop the wires bouncing around like nutters?
Reducing the bounce parameter to 0 has no effect. H8.0.487

In the Force Model tab, you have Angular Spring Constant set to 0.1. This is far far too low. These constants need to be pretty big, generally. If you set that value to 1000, it behaves politely.

Even at the default (10) it's fairly reasonable.

Ah no I did try that, they still bounce way too much, but they just stay straighter. I'm thinking string here rather than stiff wire. I was trying to get them just to “flop” down onto the torus and not bounce up off it at all. Is that possible? What does the bounce parameter do, changing seems to have no effect?

Setting bounce to zero should prevent wires from bouncing on collisions.

The wire solver was a little too aggressive in resolving the collisions in your simulation and introduced more bounce. This is now fixed in Houdini 8.0.492.