Jensen International Automotive, creator of the GM ‘LS3’ V8-powered Interceptor R, a version of which we drove in our modernised classics feature at Goodwood, and the fabulously decadent Chieftain Range Rover.
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.
Lifting the Interceptors 70s interior
The split-prone black vinyl dash is replaced with a new custom-designed, two-tone leather layout, and two rows of illuminated aluminium toggle switches adorn the revised centre console.
The trim changes transform the cabin into a luxurious habitat of leather, Wilton carpet, chrome and aluminium. There’s even quilted hide on the ceiling and in the sizeable boot, while the ‘new’ seats, which manage to be at once squashy and supportive, fit in well and provide an appropriately laid-back driving position. Only the worn, Jag-sourced column stalks (which were on the snagging list for a makeover at the time) and seat controls detract from the opulent cabin.
Unleashing the Interceptor R’s V8
But what of the beast that lurks under the car’s bespoke aluminium bonnet bulge? Well, there’s no muscle car shimmy at start-up – the R Supercharged is rock-steady at idle.
Amble through town and the blower’s never-ending soundtrack morphs from space age-warble to under-bonnet gale, but the car neatly obeys the nicely weighted steering’s inputs, and while the ride sometimes suffers niggles, it rarely gets worse than that. Unlike the R we tried, there’s no bittiness from the throttle, either, just smooth transitions and nippy step-off.
Break into open road, though, and the LSA ups the tempo in a heartbeat. Floor the throttle for instant torque and the softly sprung Interceptor rears up like an angry brown bear before throwing itself down the road at a fantastic rate.
By the time the ’box interrupts with a sub-6000rpm upshift, the engine sounds like a demonic machine gun and you’re going much more quickly than any early-70s GT has the right to.
Yet the firecracker engine never overwhelms its host – the steering is tuned for stability, roll is evident but stays manageable, and the car exhibits an affable floatiness that shames many modern equivalents. At 1800rpm at 70mph, there’s nothing more than a gentle thrum from the exhaust.
For the moment, there’s no manual override for the gearbox, but you don’t miss it: kick-down comes on request, shifts are executed smoothly but smartly, and there’s none of the mid-corner ratio-hunting that blighted the four-speed.
The stoppers generally work well and are progressive, but pedal feel is limited, and significant levels of dive mean the nose doesn’t feel as tied-down as you’d like under heavy braking. It would be possible to improve braking confidence with the addition of ABS, but the cost of the type approval such a system would necessitate makes it unviable.
The new nods to practicality work well. You can actually use the door mirrors now, the wiper clears the screen, the electric seat controls are handy and the air-con now does what it’s designed for. There’s less wind noise from the ’screen than before, but the Interceptor’s chunky brightwork means there’s still quite a commotion from drag, albeit awareness of it fades after half an hour or so. Traction control will be added shortly, but the 255mm-wide rear Pirellis fare pretty well without it, even off the line.
There are plenty of reasons to be tempted by the Interceptor R Supercharged. Unlike modern contemporaries, the Jensen avoids the millstone of being expected to deliver razor-sharp dynamics, leaving it to focus on traditional GT virtues. Sure, outright engagement is lacking, but the combination of pace, style and comfort means that fun certainly isn’t.
JIA sells a naturally aspirated Interceptor R with the six-speed box for £149,500 – add the upgraded dash, air-con and wiper kit and that becomes £155,500. While the shock factor of the R Supercharged’s pace – and the ease with which it is incorporated into such an easy-going host – is impressive, the naturally aspirated car is plenty quick and brings a layer of refinement more in line with the Interceptor’s character. In such spec, it is comfortably one of the finest modernised classics money can buy.