Rear-end snapping when downshifting

What do I need to change in the car setup? (+downshifting less aggresively helps, but not in mid to low speed corners)

 

Apply just a bit of throttle. This will stabilise the car when downshitfing.

 

Down Shift when the revs are lower
The porches don't like down shifting in the up rev range

 

And try to avoid shifting while actually in the corner.....get it done before you turn in if possible.

 

You can try softening the springs or lower the anti roll/sway bars.

 

Thanks yall