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Quick damping comparisons with king low springs and koni dampers - hard and soft settings. Shows how much your tyre will bounce on the road if you hit a bump....

Note the much quicker decay to almost steady state (additional bounce is probably in the tyre alone) on the full Hard setting. Black lines are points of impact of front and rear wheel respectively. Accelerometer mounted on the lower control arm link on the lower side of the front wheel hub...
x = seconds, y = up/down acceleration

This may be of interest to no-one... but i spent 3 weeks building accelerometers to measure this stuff... so at least i'm happy with the results...

Outcome - don't bother with the soft settings... full hard is as close as you'll get to critical damping!

Re-pressured Bilstiens on a Clubman to follow...!

I think that's very interesting! Especially that you think that you should run on full hard settings. I have kings/konis on my NA (road car, not track), and spent a while experimenting with damper settings to find what suited me best. In the end I set front and back on full hard as I found on the softer settings, the car would take a while to get back to a steady state, it would sort of bounce up and down a few extra times than I liked. I also found this would lead to traction issues in some corners.

I've read a number of comments about the place saying this is not ideal however, but I found it was the best for me. Of course I have to apologise to all my passengers for the hard ride before we set off...

I've had similar results with my tiens. I run them 5 clicks off the hardest setting front and back where others seem to prefere 8 to 12. It's probably personal taste.

So what is this ~17Hz vibration caused by? It's not the body's natural frequency, and I'd hazard that it's not the unsprung weight's natural frequency. I'd guess chassis torsional vibration...

Surely the real test is to track the acceleration of the sprung chassis?

If you model the car in 2D, theoretically - the system has a fourth mode of vibration at 16.07Hz - dominated by the pitch of the body and wheels moving out of phase with one another. The Clubman yielded results within a quarter of a Hz - this car is a little higher presumably due to significantly different weight.

We have results as they pertain to the chassis, though for the purposes of our testing they're mounted at locations that don't really yield conclusive 'ride comfort' results... which is I guess the kind of test you're referring to.

From what I can glean from your results, the springs are too hard for the shocks.
If you try some softer springs, you'll find that the shocks will be able to quell the bouncing somewhat better even on a softer shock setting.

yeah you should really fork out some cash and get that sorted

dangeradam wrote:yeah you should really fork out some cash and get that sorted

so long as you're referring to yourself in the third person:

"yes, right after you buy a torsen, a decent clutch kit and a rear main seal perhaps in an increasing order of urgency"

as its not a daily driver i might do that last two on your list eventually a new clutch will kill the diff anyway