Last month we introduced our latest project: the Jaguar XFR; a build we commenced only weeks before Jaguar announced its own XFR-S at the LA Auto Show.
Undeterred, our plan was to create a super sedan we'd call the XFR+ that could take on the best in the segment, and give existing XF owners some aftermarket options for their highly capable cars. With only 100 examples of the XFR-S coming to the US, the majority of Jag owners will never see one of these rare and elusive cats, yet our tuning parts will be applicable to every XF model, in one form or another.
When embarking on the project with GSR Autosport and Vorsteiner, it was always our goal to one day compare it to the mighty BMW M5. The German four-door helped define what a sports sedan should be and still sets the benchmark.
Going into this comparison test, we wanted our plucky Brit to do well but knew it was a daunting challenge, so we're still slightly shell-shocked by the result that saw the Jag not only hold its own but come out on top in certain key areas.
Sharing driving duties would be Michael Essa from GSR Autosport. As an accomplished track driver, professional drift racer and co-owner of GSR Autosport, he was as curious as us to discover whether the Jag had what it took to depose the king. Would it stand a chance?
To recap last month's article, our 2012 Jaguar XFR became a rolling laboratory for both GSR and Vorsteiner. Michael's company would develop a coilover suspension system for the car, based around the Jaguar's standard adaptive Bilstein damping system and adding Eibach springs on adjustable perches. They also fitted a smaller supercharger pulley to increase the boost pressure, and looked at both the exhaust system and intake to aid breathing.
While we ran out of time to fully develop the prototype intake, the XFR+ sported GSR's custom stainless steel axle-back exhaust system, that would let this Jaguar growl and roar.
For Vorsteiner's part, they designed and created a carbon fiber front lip, rear spoiler and diffuser. We would also step up to the company's own 21" wheels, clothed in Nitto Invo tires.
The final alteration came courtesy of Daley Visual, which wrapped the acres of chrome in grey vinyl to further emphasize the sporting credentials our Jag now possessed.
Wearing its battle armor, the first meeting of these deadly foes saw a decisive victory for the XFR. It was the Battle of Britain all over again, with the Germans underestimating the will to win.
When the two cars met at 5am in a deserted gas station, the luminescent lighting would shine brightest on the Jaguar. Ever since the notorious Bangle-designed BMWs hit the streets, the company's design language has been challenging to many eyes. Admittedly, the latest generations are more handsome, but some of the convex curves and sharp lines are still an acquired taste.
The F10 model may also be one of the most conservative M5s. There are few additional bulges or extra spoilers over a stock 5 Series, relying instead on badges and jewelry to distinguish it from lesser models.
Conversely, the Jaguar XF is one of the most elegant sedans on the market. Its athletic proportions and sleek lines giving the company a design direction that moves forward, rather than continually looking back.
The "R" model is again only subtly different from regular XFs, and yet those changes are more dramatic and leave little doubt as to this car's intentions. And with our embellishments laid over the top, it provided a killer combination to floor the M5 in a TKO.
With its carbon spoilers, lower suspension, wider stance and wrapped brightwork, the Italian Racing Red Jaguar was instantly appealing, receiving all the comments from fellow motorists as they wiped the sleep from their eyes, appearing to wonder why these two sedans were lurking under the lights at such an ungodly hour.
The Vorsteiner formula had again worked its magic. By adding just the right amount of muscle in exactly the right places, our Jaguar came out punching like a pro.
To be fair, if we'd also dressed the BMW M5 in Vorsteiner's latest carbon fiber pieces and plus-sized wheels, the points scoring might have been slightly different, but it would remain a victory for the Jag. Stock or modified, it's a more attractive car.
Vorsteiner JSR-V carbon front lip
Vorsteiner's carbon rear diffuser fits the stock rear bumper. Stainless steel tailpipes were powdercoated grey by GSR to match the wheels and Daley Visual's exterior trim
Vorsteiner's carbon rear diffuser fits the stock rear bumper. Stainless steel tailpipes we
Carbon JSR-V trunk spoiler is larger and more contoured than the stock piece
While we always expected the XFR+ to win the visual contest, we knew it would be a different story on the road. With its torquey, 560hp V8 biturbo motor, adjustable suspension and multi-stage traction control among its many weapons, the M5 is almost over-equipped. Add the optional six-speed manual transmission fitted to our test car, and we couldn't imagine the Jaguar had a hope in hell.
From this point we expected to be explaining how the Jaguar put up a good fight but was simply overwhelmed. But hang on a minute... the outcome wasn't clear-cut. This fight would go down to the wire.
What surprised us most when swapping between the cars was the Jag's composure. It managed to shine a completely different light on the BMW, making it feel laggy and nervous.
I can honestly say I was initially confused by the M5's behavior. At first I thought something was wrong with the car. But as we became more aware of each car's strengths, it was apparent the student was teaching the master.
During our morning canyon driving exercise - a challenging environment for such large, heavy and powerful machines - the XFR+ would leap out of each corner. It's Eaton supercharger giving instant torque and allowing it to gain a few yards on the M5. This had the effect of making the M5 feel as if it had turbo lag, taking longer for the twin-turbos to spool up. As I mentioned, this was something neither Michael nor I had previously experienced at the wheel of the F10 M5, but there it was...
Conversely, as the Jag's 5.0L V8 started to run out of puff at higher revs, the high-revving M5 was getting into its stride, and would hurtle towards the slowing XFR at alarming pace.
This trait was highlighted in our dyno tests, where the smaller supercharger pulley fitted by GSR gave the 510hp 5.0L V8 Jaguar engine an extra 20hp at the wheels throughout the rev range, but tapered off at the top-end. Ideally, it needs software tuning or bigger injectors to get more power at high revs, but for our purposes it was strong enough.
Both cars had enormously powerful brakes, allowing them to scrub speed for the tight turns with ease. Again, the Jag pedal felt a little more reassuring but neither car was compromised in this area. However, the Jag's slightly slower steering meant its corner turn-in was effortless, creating a graceful arc. Whereas, the previously stunning M5 seemed to want to turn-in early and needed mid-corner correction. Its quicker steering made it fussy through the turns - again, a trait we'd never noticed before today.
In short, the Jaguar was holding its own. Driven on a racetrack, the M5's power advantage and superior traction control system would undoubtedly allow it to pull ahead, but on these roads, the XFR was easier to drive quickly, and more relaxing to do so.
We were even surprised by the Jaguar's six-speed automatic transmission. Our 2012 car pre-dates the latest eight-speed ZF automatic, which is the best in the business and widely used. As a result, we assumed it would struggle in our test but the paddles responded to aggressive downshifts, or selected the next cog with haste. And while it wasn't as quick as many dual-clutch set-ups, it didn't detract from the experience either, suiting the XFR's more relaxed demeanor.
So the modifications we'd installed were definitely playing their part. The lower center of gravity and stiffer spring rates from GSR had reduced body roll, giving the car more poise. The extra boost pressure from the smaller supercharger pulley was also allowing it to get a jump on corner exit. And we have to acknowledge the lightweight wheels that reduced unsprung weight slightly, as well as the lower profile sidewalls on the Nitto Invo tires that offered impressive mid-corner grip for such a heavy and powerful car.
However, we've left the best until the end: The GSR stainless steel exhaust. Driven gently, or when cruising on the freeway, you had no indication of the joy that would be unleashed at wide-open throttle. Again, its stock exhaust unfairly handicapped the M5 but we advise you to watch our online video to hear the glorious engine note from the XFR+. It made your spine tingle, especially bouncing off the canyon walls in the crisp morning air. You'd hear the V8 several corners before it emerged, and the sound would reverberate around the rock face, leaving our entire crew grinning.
Our two tuning partners came up trumps, creating a package for the XFR that's put it on par with one of the best super sedans in the business on extremely demanding roads. And as we examined last month, many of these parts will fit other XF models in the range.
On our drive home, both the M5 and XFR returned to their default mode as highly capable high-speed transport, with little to choose subjectively between them. So if you're in the market for a new or used sports sedan and want something different from the mainstream, we've hopefully given you a few more reasons to put the Jaguar XFR on your shopping list alongside its German counterparts.
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
Drivetrain stock six-speed automatic
Brakes stock two-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
Contact vorsteiner.com, gsrautosport.com, daleyvisual.com, minagallery.com, jaguarusa.com
2013 BMW M5
Engine 5.0L V8 DOHC direct injection, two twin-scroll turbochargers, reverse flow, cross-bank exhaust manifold, Valvetronic, Double Vanos
Drivetrain six-speed manual transmission, Active M Diff, RWD
Suspension Double-wishbone front, multi-link rear, adjustable damping
Brakes 15.7" rotors f, 15.6" r drilled, six-piston calipers f, single-piston r
Wheels & Tires 20x9.5" f, 20x10.5" r Style 343M wheels, 265/35 R20 f, 295/30 R20 r tires
Exterior M-specific front spoiler, flared fenders, side gills, mirrors, rear apron, diffuser, trunk spoiler
Next Month We'll look at Vorsteiner's development of the carbon fiber styling parts and Daley Visual's vinyl wrap.