The following cheats do not work in Practice Mode. To use them, you must type them as your name. 
You will hear an engine rev up if done correctly. To enter multiple cheats, after typing the cheat, do not press enter. 
Instead, backspace to the beginning and type either a new name or another cheat. Repeat as necessary.

Code                     Result 

HEDGEHOG0 Activate Cheats 

NOGAS Unlimited Gasoline 

CLASSIC 1956 KHK Bike