Set-up analysis with data logging

[silente]

Hi,

i had ordered a copy of the new Jorge Segers Book on data logging.

i have seen some of the topics are about quantifying roll stiffness distribution, wheel loads and Frequencies and Shock Absorbers.

I have an idea on how to calculate roll stiffness distribution starting from suspension potentiometers data.

Which way would you chosee to do so?

As about wheel loads as well, without using strain gauges, you can isolate something but to go on wheel load you have to put a lot of informations from outside...like Cg height, stiffness, etc.
Have you ever tryed to do such a calculation on your data?

Last, it's easy to calculate dampers speed, to see their working way; i tryed also to perform some calculation based on Fourier Transfer analysis but it's not easy.
How to understand if your dampers are working properly ( a part from the balance Bump-Rebound), to see for example if you are stiffening them too much or if you are in the opposite situation?

thx

[Rubinho]

There's a full set of calcs for wheel loads in this months (September) RCE, in the Aero Mapping feature.

After reading the article and being a little sceptical about the accuracy of such equations from car data, I made a set of maths channels to calculate wheel loads from damper data and compared it with the load cells from the car. It correlated quite well, not perfectly though.

You don't need anything about Cg height etc. You can tell everything about the individual wheel's load from the damper displacement, damper velocity, spring rate and damper rate.

[silente]

Thanks for your reply.

Unfortunately i didn't read the article you're talking about but for sure if you know spring rate and motion ratios you can calculate wheel loads.

The not correct matching is connected in my opinion to the variation of Motion Ratio during wheel movements and probably to a different stiffness of the springs from nominal value.

But what about WT? Would you use anyway Springs and bars stiffness and motion ratios or you would take another way?