The aircraft collided with the ground in a high speed dive and totally disintegrated. Impact created a 7' crater and material blew out for 100 yards. The engines were recovered at the 14 ft level in the crater. The aircraft took off at 2215 from Baytown, TX. At 2334 radar and radio contact was lost. At no time did the pilot indicate that he was having any difficulties. As radar contact was lost the return went into coast mode for 8 sweeps or 38 seconds. One thing that can trigger the coast mode is a rapid rate of descent in excess of 500 ft/minute. On 8/1/83 the pilot owner experienced a total electrical failure in this aircraft while enroute from California to Dallas, TX. The battery cables were found corroded and loose. These were cleaned and tightened and no further record of electrical maintenance was noted. After the accident the tail light bulb was sent to the NTSB lab for analysis as to its illumination at impact. Their findings indicate the bulb was not illuminated at impact. There are no provisions for an emergency lighting system in this aircraft.