While Jaguar's 370kW+ XF-R is still many months away from its launch at next year's Detroit Auto Show, German tuner Arden has already released its own interpretation of a big-power Jaguar sedan. By taking Jaguar's familiar AJ-series 4.2-litre V8, stroking it out to 4.5-litres and perching a supercharger atop it, Arden has managed to coax a full 410kW out of the XF's mill, and in doing so have well and truly beaten Jaguar to the punch.
Thanks to a custom crankshaft and rods, displacement is now a handy 300cc bigger, while a re-mapped ECU optimises fuel mixtures and ignition timing for maximum power. An uprated supercharger stuffs more boost into those eight cylinders and a low-restriction exhaust helps that Jag V8 exhale. Oil and coolant circulation have also been improved by Arden, so owners should be able to keep the AJ 21's V8 in the upper reaches of the rev range without worry or consequence. Perfect.
However, for those who prefer their Jags to be a little more... subdued, Arden offers a naturally-aspirated version of the 4.5-litre stroked V8, which manages to bang out a very respectable 283kW of power. If you really don't want to upset your comb-over though, Arden also has a range of basic upgrades for the base model's diesel V6, which takes power from a lowly 154kW to a useful 186kW.
While Arden also offers a set of lowering springs and Bilstein shock absorbers for the XF, as well as a pretty chunky 390mm/6-piston front, 340mm/4-piston rear brake kit (with ceramic rotor option), the centrepiece of the AJ 21 package is undoubtedly that gorgeous seven-piece bodykit.
Consisting of completely redesigned front and rear bumpers, side skirts, fender gills and a bootlid spoiler, Arden's AJ 21 bodykit gives Jaguar's XF a menacing quality that's notably absent from the standard car's business-like (and somewhat dowdy) exterior. If the AJ 21 were a meal, it'd be roast quail with a wasabi glaze. If it were a person, it'd be Mike Tyson in a tuxedo. Refined and sophisticated, yet still more than capable of leaning over, biting your ear off and making your eyes water.
From the reshaped semi-circular grille to those LED running lights to the subtle air intakes on the trailing edge of the side skirts, the Arden kit absolutely nails down a properly sporty look for the XF, and when it's paired with that 410kW V8 (and perhaps those ceramic brakes), you've got one seriously purposeful British sedan.
It looks like Jaguar's already got some competition for the yet-to-be-launched XF-R. For more information on Arden's AJ 21 package for the Jaguar XF, visit the link below.