Give it some welly.

When I first heard the British expression 'Give it some welly', I did not know what it meant, and I gave up my wellingtons. (just joking) Yes, they are aptly named after the 1st Duke of Wellington. So, the boots - wellingtons - have only so much to do with the expression as they are worn on your feet which (at least one of them) you push the accelerator pedal with.

So come on, do it Mate!

Give it some welly.