URD's Shiro / GT500 Nismo understeering in corner apexes

[Billy Pilgrim]

I rather like URD's Shiro / GT500 Nismo mod.

But at the apex of corners when I'm driving at the slowest point of the corner, the car undertseers surprising badly.

Could anyone suggest a setup tweak that may help this? (I don't know much about car setups)

Any help would be great