On September 9, 1998, at 1901 hours Pacific daylight time, a Cessna 170B, N8245A, sustained substantial damage when it went off runway 30 right and nosed over at the San Jose International Airport, San Jose, California. The private pilot and his passenger were not injured. Visual meteorological conditions prevailed. The pilot stated he had been in the pattern practicing touch-and-go landings with an instructor for approximately an hour. After his passenger arrived and took the instructor's place, he went out to practice a few more landings. He took off without incident, flew to downwind, and was cleared to land. A normal 3-point landing was accomplished and he prepared the airplane for departure. He retracted flaps, applied full power, pushed forward on the yoke, and raised the tail. After proceeding straight down the runway a short way the aircraft began to drift off centerline. The pilot stated he was correcting with left aileron and right rudder to bring the aircraft back to the left when it suddenly went off the runway. The aircraft departed the runway into a grassy area and overturned. Both wings were damaged, the prop was bent, the forward section of the fuselage was damaged, and the top of the vertical stabilizer was crushed.