A notoriously tricky car to tame in GT5, here's my base layer setup for the NSX that gives a neutral balance on corner entry and exit. You can induce some manageable oversteer on corner exit if required with throttle control.
I've been racing the car in the racedepartment Japanese Sports car Club events, so it's "upgrades" have been picked to meet those regulations. However, you could use this setup with any non upgraded or highly upgraded car while you find your feet with it.
Power: 380bhp
Weight: 1270kg
Tyres: I've tested with Sports Medium up to Racing Hard.
No spoiler or wing upgrades.
Sports ECU
Racing Exhaust, Upgraded Manifold, upgraded catalytic
Intake, Upgraded, with racing filter
Double clutch plates, Sports flywheel, LSD
LSD (rear only) = Initial Torque 20, Acceleration 33, Braking 38
Ride Height = Front -16, Rear -16
Spring rate = Front 9.8, Rear 12.8
Damper extension = Front 8, Rear 8
Damper compression = Front 7, Rear 6
Anti-Roll bar = Front 4, Rear 4
Camber = Front 2.2, Rear 1.8
Toe = Front -0.14, Rear 0.06
For a more edgy race setup for those extra 10'ths (when you're used to the car), try dropping the ride height to -20 front and rear, and increase spring rate by 3.0 front and rear. Racing Hard tyres maybe a minimum here.
If you try the above, let me know what you think and what else you've done. Thanks