According to the pilot, the weather was calm and he made an approach to runway 25. The airplane touched down approximately 2,500 feet down the runway. He applied "heavy braking," which did not stop the airplane. The pilot attempted to turn off the runway; however, he was not able to make the turn and the airplane went over an embankment and nosed over. The pilot reported that there were no mechanical problems with the airplane. A deputy from the Nevada County Sheriff's office interviewed the pilot. The pilot stated that the resulting crash was a combination of too much airspeed and not enough runway to stop the airplane. The airport/facility directory for the airport indicated that the runway is 4,350 feet long.