That is an incredible bit of observation right there Fit, you definately know what you're feeling on this tune.
I noticed the speed/stability correlation too, it makes perfect and realistic sense. As speed increases the need for steady control increases. There are two main reasons I see for this.
The first reason is that at higher speeds our reaction times are diminished, we simply have less time to react to chassis movements. the higher rebound value mutes these responses and gives us a touch more time to react.
The second reason is aerodynamics. A recent bit of research I dug up mentioned the connection between damping and aerodynamic downforce. The effect of downforce essentially weakens the springs and damping values. Technically, the car becomes "sloppy" at higher speeds. Once again, proportionally high rebound values help diminish the severity of these effects.
At the same time, all this stability and control inhibits low speed response. No aerodynamic load allows the suspension to be stiff and minimizes chassis movements. This stiffness in comination with the damping levels make the car feel sluggish and muted on tracks like Tsukuba.
The numbers i've been crunching recently have been toying with these relationships. The current issue is finding my "generic" or "jack-of-all-trades" values.
I may be able to get away with a slightly lower rebound multiplier, but i'm in danger of losing high speed stability in the more powerful RWDs.
The testing continues....
