Using a lot of toe in to "add more rear grip" is a bad idea and a common mistake made by many drift suspension experts. It is not adding more rear grip, just rear steer and makes the car a lot more twitchy and hard to drive. The car will spin easier and tend to straighten out and shoot straight into walls and stuff with too much toe. To get more rear grip, you must play with the springs, bars, shocks and tire pressure. A little rear toe in helps the car's slide stability.