This term is used amongst petrolheads and radio-controlled car
enthusiasts to describe additional optional items added to a car
to improve its performance. It includes things like turbos
, big carburettors
and so on.
Typical usage: "What hop-ups are available for the T-Maxx?" or "My Mini-Z has a heap of hop-ups: front one-way, turbo circuit, foam tyres and more."