My F1R right now is in the same boat...finally got tires on it that give me enough rear grip for my liking but it won't turn. So I have to run a lot of drag brake as well just to get the car to turn. I tried the suggested Shimizu tires that everyone likes for asphalt and found with my car that at the start of the race the rear was too loose until the tires got up to temp. But once the tires got up to temp then the car developed a huge push.