Stiffer Springs doesn't make a Car slower in General, and sometimes it's faster. And the Porsche Cup Car from Kunos is based of off the Italien Cup, so maybe there are a few differences which makes it faster, who knows. If you compare some Laptimes from the GTLM and GTD Cars who Raced on the Glen two weeks ago, a few of them are even Faster then the Cars from Assetto Corsa. Not to mention, that Temperature, humidity etc. can be different which leads to a huge difference in Laptimes too.car is not faster, it has much stiffer springs just like the real thing, wich makes it even slower
also ABS is disabled