TECH: R53 PULLEY AND INTERCOOLER UPGRADE

PARTS AND COSTS 17% pulley, belt, colder NGK plugs, modded bypass valve (£211.04), Airtec intercooler (£399), fitting (£250)

TOOLS REQUIRED Spanners and sockets, pulley removal and tensioner tools, breaker bar, penetrating fluid, Loctite

TIME TAKEN 4 hours plus

DIFFICULTY

Upgrading an R53’s supercharger pulley to a smaller item is a logical move; indeed, MINI themselves did it with the JCW, fitting an 11% reduction pulley from the factory.

There are various options on the aftermarket, but 17% seems to be the sweet spot – the most extreme you can go while still maintaining everyday reliability. It’s not just a case of swapping the pulley though, there are other knock-on mods