The Viper ACR has quite a weird past, transforming into a GT3 car. It was a GT2 car at first, originally named Viper GT2. It was the ONLY direct competitor to the Porsche GT2 at that time. The Viper later started racing in GT1 (yes, a hypercar class category) and eventually in GT3. ACR used to simply be a lighter, sportier, more enhanced, preppier package for the Viper in the 1990s and early 2000s, and it would later be called the Mamba Package in the third-gen Viper, only to be renamed back to ACR in its fourth-gen. (TA is essentially "tamer" ACR as noted in the fifth-gen model.)
I've noticed that more recent ACRs, especially the final one, drive more like a GT3 car than a GT2 car. Their priority is never based on straight line performance. The MC20-based GT2 stradale still produces 1102 lbs of downforce at 174 mph, whereas this car makes 1764 lbs at 177.
As far as the McLaren Senna goes, it would have been a GT3 car had it not been for the extreme power or the high price tag. Today's Corvette ZR1 (the C8) is based on the GT3 Corvette, and not on any GT2 car. The Mustang GTD, same thing. Nowadays, it's MOSTLY the high-output cars that are GT3. GT3, again, is what GT2 used to be (I've noted this in one of the C8 ZR1 pages.)
