give it some welly

verb2

1. •
   (UK, slang) To increase fuel or power to an engine, as to a car by depressing the gas pedal.

   • Believe me, if you give it a little welly down a twisty B-road this car feels pretty entertaining — 2000
2. •
   (UK, slang) To apply great physical effort to (something).

   • First they always obey the golden rule ‘Whatsoever thy hand findeth to do, do it with thy might’ (Ecclesiastes 9:19), which translates as ‘always give it some welly’. — 2008