The real time cars started life as showroom Type R's, there is actually not that much done to those engines. The rules for that series do not allow you to tear apart the block and rebuild it. you are basically only allowed to tune it. I know they use an aftermarket airbox, i want to say comptech but im not 100% sure. And exhause modifications are allowed also. But that is about it. Most of the money and such go into the suspension.Even then there is only a certain amount you are allowed to change on that.