Unlike that car, the modernisation of which was largely outsourced, the £180,000 Interceptor R Supercharged you see here, the normally aspirated version, the convertible Interceptor Rs and the Chieftain, are almost entirely rebuilt (starting with a full shell refurb) by JIA’s workshop staff at its base in Banbury. Only retrimming and painting took place elsewhere, the former at long-time marque restorer Rejen near Winchester.
Powering the Interceptor R range
The ‘Supercharged’ bit comes thanks to the installation of the LSA engine – essentially a blown LS3 – which makes 556bhp (a full 127bhp more than the ‘R’ we drove) and 551lb ft, dispatched via an upgraded prop shaft.
This tune matches that of the LSA-powered Cadillac CTS-V. The six-speed GM auto gearbox seen here is now available in all ‘R’ models; our previous encounter was with a four-speeder. The naturally aspirated V8 version produces a not so measly 429bhp, while the convertible is available in both V8 and supercharged V8 versions.
The R Supercharged also demonstrates a host of refinements that JIA is introducing to its range. Changes include a bonded windscreen in place of the traditional rough and leaky rubber seals, electric front seats and column stalks sourced from a Jaguar XJS, larger, body-coloured heated door mirrors in place of the fiddly little chrome jobs, an effective single wiper replaces the pair of flappy originals and there’s upgraded air-con.