Professional race cars vs street tune cars ?

[D.J.T]

I was wondering if a street car can be tuned to be faster than a professional race car like, FIA GT1 for example, no prototypes like F1 or LMP1. Redline time attack cars where you have the unlimited class some will have up to 900HP+, Giant functional wings etc, there is basically no limits to what they can do to their cars.