Change to lower gears at high speeds

Hi, is there any option to change, for example, to first gear if i'm going at 150KM/h?
With the keyboard the game doesn't allow me to reduce the gear, for example, if 2nd reaches its top RPM at 80, i can't put in 2nd if i'm driving at 85KM/H.

Thanks,
Juan.

 

Disable gearbox assistant.

 

Nice, thanks!