[phoenix]

Increasing bump stiffness on the rear will increase the rate of weight transfer (from acceleration) to the rear, which would tend to add oversteer.

Increasing front rebound would tend to reduce corner exit understeer, which is the same as increasing the tendancy to oversteer. This is because the stiff damper rapidly takes load off the front tyres under acceleration, giving them more grip, assuming that you were using the maximum grip available from the front tyres up to the point in the corner that you begin to accelerate.

I'm not sure I would have different bump and rebound setting from left to right on the car. It is more usual to have the same settings on both left and right hand sides of the axle, just as it is usual to have the same spring rates.

If you are oval racing, that would be a different matter... oval racers do all kinds of stuff that 'circuit' or 'road' racers would never consider.