Cheatcodes:

Extra Speed 

Pause game and type "give me speed" 

Extra Turbo 

Pause game and type "give me boost" 

Monza: Good time:

To get a good time at Monza, set up the cars wing as low as possible but still feel comfortable. Fast and slow bump or rebound should be low. Packers should be 20 to 30. The more packers, the lower the ride height. Get as much speed as possible in corners and less braking distance. Try to avoid bumps and do not using throttle assist [F7].