Everyone on carpet foam tires runs 6* caster blocks, they will make car steer little less going in but more mid to exit. And the softer tires that were suggested too should make it rotate more. The stock hubs for the rear are 0* hubs(which gets you 2* total per side), so less toe in the rear will give less off power steering and more mid to exit steering. All of those things should help you out and after try them out might want to try moving the rear arms forward from full back position by like .060" or .030" to make it steer more middle of the turns. Also the racers car that you drove it'd be good idea to get their setup and also see if they mind showing you what dope and how they apply it to their tires and what compounds they are using.