The aerodynamic explanation for having understeer on entry and then oversteer on exit is simple – not enough.wesley123 wrote:And why I think the snap understeer is mechanical, and not aerodynamical.
1. On corner exit, a car just simply doesnt out of a sudden loose rear df, certainly not with the exhaust blowing the diffuser.
2. if there was a lack of rear df it would be more noticable under braking since then there is less exhaust blowing, thus less rear df. Yet, there is a lack of front end balance under this condition.
3. Because they now (finally) have a decent EBD they see an improvement in rear df, thus a rear balance shift, making a sudden loss of rear end grip due to aerodynamics less likely.
4. It seems mechanical because of the way it is presented, like said, a sudden loss of rear df on corner exit doesnt seem that likely.
I must say I have less knowledge of suspension and tires, but I am confident the snap oversteer is caused my a mechanical problem, and not by aerodynamics.
On corner entry, you need the front tyres to bite to turn you in. It doesn't matter (that much) if the rear tyres are biting that well. So, an increase in overall downforce, and hence overall car grip will cause the tyres (including the front) to bite better, and will help stop understeer.
On corner exit, you need the rear tyres to bite, and not spin up as you try to apply the power. It doesn't matter (that much) if the front tyres are biting that well. So an increase in overall downforce, and hence overall car grip will cause the tyres (including the rear) to bite better, and will help stop oversteer.
It doesn't require a sudden loss of rear downforce to cause the sudden oversteer, or in fact any loss at all. Instead, all it takes is a sudden (or even fairly gradual) application of power to cause the rear tyres to go from biting to spinning, and your tail's on it's way round in a circle.
