Here are some cheats and tips for the game GT 64 Championship Edition.
801608D8 0001 Always Place 1st
8015FC35 0001 All Races 1 Lap
8015FD09 0063 Always Have 99 Points
8015FC35 00xx Total Laps to Race Modifier
Replace xx with any number 0-9 or A-F
D01A10B5 0010 Press R For Nitrous Boost
81162F28 4077
D01A10B5 0010
81162F30 4077