physics, weight transfert

[NaN]

You could try to reduce the suspension bounce, rebound values. Play a bit with the stiffness, antiroll setting.

Btw do you mind to share your config? Can you name the track or upload a pic of the curve you are testing on?

Some detail info:

The suspension model is completely kinematic(no chance to have something like anti-dive geometry).
Tire contact forces are applied at wheel center. I've tried to fix this by moving the application point to the contact, assuming a very rigid suspension. I called it the Elchtest(moose test) mod at that time. It broke about half of the cars, let them roll over the side due their mass center. But there has been visible, feelable mass transfer hehe.
There are also issues due to rigid body and spring/damper model. You have 1500kg falling down each time step and being pushed up by the spring/damper where the damping forces are working against the movement. You can see it while running "vdrift -debug". In the real world the damping values should be zero for a car standing still. I've got some experimental code to deal with this, but it will most probably break car handling too.

Maybe it is time for another special mod, we need a better model for the karts anyway.