Kick down is a term for autos only - press pedal to floor, box will change down and hold lower gear.
Not relevant to manual box! Ex AA Series III LWB Safari - Gone
300TDi Disco (bought new - terrible car) sent back after 18 months
Freelander 1 Estate - leased, given back at end of lease
200TDi Disco (bought from a mate with 100,000 on the clock) - Gone
Disco 2 TD5 - sold and exported to France
FR2 TD4 GS - Gone
FR2 SD4 HSE - Now changed for a DS
New model ex-demo Evoque S 180 in white
Unable to order a new DS, so gave up. Now have a Volvo S90 Recharge.

OK, then define a term that suggest the same thing with "kick down", but for a manual...
WOT? Full throttle? There is no throttle on diesel engine... So ?

I'm sure that the OP has understood what I meant to say...

Alex your English is brilliant (and my Romanian is non-existent - I did try to learn it but got no-where ). However I have only ever encountered "kick-down" as a technical term with auto boxes. For the usage you are looking for I think you'd need to say "put your foot down" (English) or "floor the pedal" (?American) or something similar.
The previous poster has a manual car and asked what the term meant - the only answer is, nothing at all on a manual car. Ex AA Series III LWB Safari - Gone
300TDi Disco (bought new - terrible car) sent back after 18 months
Freelander 1 Estate - leased, given back at end of lease
200TDi Disco (bought from a mate with 100,000 on the clock) - Gone
Disco 2 TD5 - sold and exported to France
FR2 TD4 GS - Gone
FR2 SD4 HSE - Now changed for a DS
New model ex-demo Evoque S 180 in white
Unable to order a new DS, so gave up. Now have a Volvo S90 Recharge.