I had the same experience as Mike at Snowbirds. My car was lifting in the corners and I remedied it and went slower, so I went back. It looked horrible but it was faster.
I've always thought that a car will be fastest when it is pushed right to the absolute limit. If it's too easy to drive, it's probably not fast enough. In a sense, get it to the point it will traction roll and then back off just enough that the car is stabilized and can make it around the track. Then you're in the zone.