Help me with Lamborgini LP-560 about the suspensions..

[marktyper]

when at high speeds at nurburgring, I always end up swaying the rear of the car cause I can feel the heaviness of the V10 engine but I tried to adjust the spring rate at the rear .. it's way more better than stock but still, is kinda heavy in the rear than the F430 Scuderia is perfect. someone can help me? Thankyou!