Having driven and enjoyed various Jaguars over the past 12 months, it occurred to us that you never see tuned examples. With their supercharged V8s, lithe chassis and obvious appeal, it seemed like a wasted opportunity, so we decided to take a crack at it ourselves. How difficult could it be?
We reasoned that the XFR was the most suitable basis for the project, and obtained a 2012 model a few weeks before Jaguar's own XFR-S was announced at the LA Auto Show. That dropped a fly in the ointment, but with only 100 cars coming to the US, and the price tag likely to be high, we're hoping it will pique interest in sporting Jags. Any existing owner of the XF or XFR will still be able to apply our parts to their car.
So undeterred, our first task was to scour the internet and research available performance options. Cue crickets, tumbleweed and embarrassing silence.
Aside from a few small companies offering a handful of parts, there was very little available. So we decided the best course of action would be to gather an elite team of specialists and create a custom package.
The plan was hatched during the construction of our Porsche 911 rally car for the eBay charity auction (EC 12/12). That car was built by GSR Autosport in Lake Forest, CA, and as road and racecar builders, they were confident the Jaguar could be improved so agreed to be involved. However, it would take more than mechanical parts to cause a splash, so we also persuaded Vorsteiner to get onboard with cosmetic enhancements.
Known for its exquisite carbon fiber aero pieces and wheel range for high-end European cars, Vorsteiner has a great reputation for design and execution. Unlike many styling companies, they exercise restraint and produce what the car needs rather than what looks outrageous. So Vorsteiner styling parts are generally on the subtle end of the spectrum and certainly in keeping with the vehicle we wanted to build.
We'll look at the design aspect in greater detail in a later issue, but the process started in Vorsteiner's in-house design studio. Manned by car company stylists and clay model makers, the design process is identical to how a carmaker would approach the task.
The design team is led by Vorsteiner owner Peter Nam, who consults with a designer to create the initial illustrations seen here. These renderings become the basis for the stylists to apply modeling clay to the car to create the desired shapes. The well-lit studio and vehicle lifts mean the lines can be assessed from every angle, and changes made as necessary. The experienced team also considers how the part will be manufactured, whether it would need to be made in multiple pieces, or whether the angles are too tight for molding. They also analyze fixing points to consider how the finished part will eventually be fitted to the car.
During our discussions, all parties agreed that the XFR, with its deep front spoiler and sculpted side skirts didn't need many enhancements. So the additions were limited to a carbon fiber JSR-V front lip, rear diffuser and trunk spoiler. When combined with a set of Vorsteiner wheels and GSR's lowered ride height, we felt the car should look sufficiently sporty without appearing overly "modified".
Vorsteiner's designers and modellers were faithful to the rendering in all but the rear spoiler. During the clay stage everybody felt the design was too similar to the stock XFR spoiler, so the stylist devised a more ambitious design that remained within the original brief.
The trunk spoiler should fit all the XF range, from the 3.0 Supercharged to the 5.0 Supercharged and XFR. We also suspect the front lip and rear diffuser will fit all the models, but we've yet to verify that.
Without doubt, the one-piece Vorsteiner VS-190 wheels will fit any XF and for this application they're sized 21x9" front and 21x10.5" rear, giving us a plus size over the 20x8.5/9.5" stock wheels.
With plenty of finishes to choose from, we selected Gunmetal Glossy powdercoat to give them a durable but restrained coating, and then fitted 255/30 and 295/25 Nitto Invo tires respectively, giving us a slightly wider rear than stock.
As we mentioned, the Vorsteiner styling will be covered in greater detail in a future issue.
More familiar with Porsche and BMW platforms, GSR is expert at chassis set-up and welcomed the XFR challenge. Their recent win in the Formula Drift series with an E46 M3 against better-funded teams highlighted their overall abilities, so we had complete faith in them.
Working closely with Bilstein on its road- and racecars, GSR delved into the Jaguar's stock Adaptive Dynamics system and found it was based on Bilstein components. After road and track tests, they liked how the adaptive system worked, so decided to keep it and incorporate a coilover system that would allow them to use stiffer springs for more control, while providing ride height adjustment as well.
The company sourced a set of collars and perches that would permit the new springs to be mounted to the factory dampers. Then all they had to do was determine rates for the Eibach springs.
After more testing, they finally settled on the combination we have here, which will be put to the test next month when we road test the car against its stiffest competitor.
GSR also fabricated an axle-back exhaust system for the car from stainless steel. Again, they experimented with several muffler designs before settling on a combination that gave the right level of noise under acceleration, but didn't drone when cruising. This is an extremely difficult balance to find, and one that can take months of development. Fortunately, GSR managed to find the right combination of pipes and mufflers in our tight schedule to create a very pleasing sound.
With its blown 5.0 V8 up front, GSR found it was relatively easy to uncork the engine and make it howl, but keeping the level of refinement we wanted meant spending extra time to fine-tune it. The result should please most tastes and can be heard on our video that is available next month.
As an extra flourish, the tailpipes were finished in a grey thermal powdercoat, designed to withstand high temps and match the wheels and exterior trim on the car.
Finally, GSR sourced a smaller supercharger pulley from Mina Gallery. This has the effect of increasing boost pressure to make more power. With the engine adjusting its fuel mixture to match the air volume, the engine responded well to this relatively simple modification.
Although not seen in our photos, there's also a prototype cold-air intake system that replaces the factory airboxes. Initial testing found that open filter elements absorbed too much heat from the engine bay after prolonged driving, despite the presence of factory intake scoops. As a result, they plan to create heatshields that should isolate the problem but, for now, the car is running on K&N filter elements inside the factory airboxes.
We hope to have dyno numbers next month along with our seat of the pants appraisal of all the modifications.
Again, the exhaust, pulley and suspension mods will fit the regular 5.0 XF Supercharged, and the coilovers suitable for the XF 3.0 as well.
Finally, we enlisted Joshua Daley from Daley Visual in Rancho Cucamonga, CA. He specializes in vinyl graphics and car wrapping. We've worked with him in the past and his knowledge of the right materials and techniques makes him the best in the business if you want to transform your street or track car, motorcycle, truck, etc.
For this application, we wanted to remove the acres of chrome on the XFR to update it.
Jaguar does offer the XFR Black Package that includes gloss black window, grille and intake surrounds as well as dark grey wheels. But since our car didn't have that expensive option, Daley Visual was a great solution.
We selected a grey vinyl that was close to the color of the wheels and asked him to cover the window trim, grille surround, air intake frames, side trim and the decorative strip between the tail lights. He even covered the "R" logo on the badges to complete the job.
Using only a knife, heat gun and tape measure, Josh set to work. Surface preparation is important, but knowing how much the film can stretch, and the angles it can take were key to a perfect job. By the time he was finished, all the chrome had gone, replaced with the more elegant grey trim.
The grey vinyl was a huge improvement, but we would have liked to wrap the entire car in a different color - matte grey was top of the list, but time was against us, even though Josh works at high speed.
2012 Jaguar XFR
Engine 5.0L V8 32v with Mina Gallery supercharger pulley, GSR 3" stainless steel exhaust with powdercoated grey tips, GSR intake system
Brakes stock four-piston calipers, 15" rotors f, single-piston, 14.8" r
Suspension stock Adaptive Dynamics suspension with GSR coilover adapters, Eibach springs
Wheels & Tires 21x9" f, 21x10.5" r Vorsteiner VS-190 wheels, finished in gunmetal powdercoat, 255/30 R21 f, 295/25 R21 r Nitto Invo tires
Exterior Vorsteiner carbon fiber JSR-V front spoiler, rear diffuser, trunk spoiler, Daley Visual grey vinyl-wrapped chrome trim
Next Month We road test our Jaguar XFR+ against a German competitor that sets the benchmark in the uber sports sedan segment. Will our custom modifications give the Jag the edge? We can't wait to find out...