MODIFIED
It started with a simple supercharger pulley but this XFR ended up with an impressive 650bhp spec courtesy of Wraptor Customs
I DIDN’T buy it because it was a Jaguar... I bought it because it’s a five-litre V8,” laughs Nathan Davies when we ask him why he chose the XFR you see here. Although he has owned Jaguars previously, he was inspired when a couple of friends acquired V8-engined cars and discovered just what cracking value the XFR represents against the likes of the Mercedes C63 and the BMW M5.
JW readers will already be well aware that the XFR needs to make no excuses to hold its own against the two Germans and as we’ve discovered, there’s also plenty of potential beyond the factory rating of 510bhp.
When Nathan first acquired the car a couple of years ago it was running a relatively mild upgrade consisting of a smaller supercharger pulley and a remap to suit the increased boost this produces. It wasn’t until he met Dudley Ginn of Jaguar specialist Wraptor that he discovered just how much more potential there is in the supercharged Jaguar AJ-V8 engine. In short order that smaller supercharger pulley was joined by a larger crank pulley – the effect being to further increase the driven speed of the supercharger to provide a further boost increase.
At this level of modification it’s sensible to map the car properly on a rolling road rather than a ‘one size fits all’ offthe-shelf remap but before heading to the dyno, a set of free-flow catalytic converters was fitted, complementing the Spires exhaust which had already been fitted. And yes, eagle-eyed readers may have spotted the Akrapovic exhaust tips but Nathan fitted them purely because he liked the look of them.
In order to keep the charge temperatures down, the factory chargecooler – essentially a watercooled intercooler – was also uprated to Wraptor’s larger aluminium version.
The end result was a peak power output of 650bhp with torque to match and it’s testament to the basic engineering of the XF that very little else needed changing to cope with a power output more than 100bhp over standard, although the car has also received Wraptor’s gearbox remap which smartens up the shifts and gives it a generally more lively feel.
Not that this stopped Nathan going further into the menu of upgrade options offered by Wraptor: the car sits some 15mm lower thanks to a set of Spires springs and rather obvious in their green finish are the big calipers which form part of Wraptor’s own brake upgrade.
Something you won’t see in the photos but which is absolutely tremendous is the result of the active exhaust valves installed by Wraptor. Controlled by a switch, they effectively bypass the rear silencers and
