The article can be found at this link:

2012 Jaguar XFR - European Car Magazine

The Vorsteiner carbon elements look absolutely phenomenal and it seems that GSR Autosport has been able to create a one-off exhaust system for the car. I can't wait to see what their dyno numbers show!

Hopefully it gets good reviews when pitted against the new F10 M5 as well!

 

I live local to GSR and visited them after seeing this article. They built the exhaust, which was for sale for $600 and still may be, but don't sound like that's something they want to do again. It was powder coated and the finish was coming off at the Y at the tips. They said it gained 40 hp with the exhaust and Mina pulley, but that the power tailed off at the upper RPM's so a tune would be a good addition. They all commented on how good it sounded though and the video sounded good. Can't remember the brand of mufflers they used but have it in my browser history if anyone really wants to know.

 

So was the exhaust just axle back? Did they remove the center resonator?

 

It was just axle back. I checked my browser history and their mufflers were made by Vibrant, but I don't know what exact model.

 

Here is a copy of the magazine article. They seem to take a while to post things, so I scanned it. Enjoy!Customized XFR vs. M5.pdf

 

An excellent read. Thank you!

 

Here is the latest installment of the XFR modifications done by European Car. Looks like with the pulley and exhaust that the ECU is pulling timing and reducing peak hp. So a tune is definitely going to help in that area. I had mine dyno'd recently and I also was at approx. 460hp and 405 ft. lb. at the wheels (average of 3 runs) and they were done on a DynoJet dyno as well.

 

I think that the coil over arrangement sounds really good; the fact that it can be installed over the stock struts. I am not sure that going any stiffer on the springs would be good idea for street cars.

Does anyone know (or measure) what size (diameter) the rear sway bar is on the XFR? I own the 5.0 NA XF and the bar is only 0.55" which is way undersized for this car. I would love to change it to at least a 3/4" bar which would improve the already decent handling of the XF a great deal more.

Albert

 

Are you sure a Tune can fix that? It could be that the injectors are maxed out and can't spray anymore fuel at those RPMs or it could be the fuel pump. Either way, I think it's a mechanical issue, not a tuning one. One thing that video didn't show, is an actual comparison to the M5, I mean what were the results of the little bit of mods they did to the car?

I myself would like to one day get a splitter, defuser, and lip spoiler for my car, (all carbon fiber of course) but I just have an NA XF, nothing too fast.

 

I would have to disagree... Looking at the Dyno run and the AFR chart nothing suggests that it is leaning out. In fact it's actually the opposite, it looks like they go quite rich which is a telltale sign of timing pull and fuel dump.

Without having any information on the stock fuel injectors I would severely doubt that they don't have a safety margin built into them. These are eight injectors with 5 L of displacement... To squeeze out additional horsepower when it's a load shared across eight injectors and eight cylinders is a much lesser task required by the injectors...

I'm not saying a Tune would or would not help, but there's a very good chance that they were truly heat soaked. I've never been on a single Dyno (and I've had my fair share of Dyno runs not with the Jag, but with a lot of other toys that I've had and no Dyno run has ever been able to emulate the amount of air that's moved on the open road).

 

You're probably right. I see they used the Mina pulley and most likely the tune that comes with it and may not take in account the extra flow from the intake. There don't seem to be any real software out that allows anyone to do a real tune on the car, at least that I ever found. Since everything is a one off, except the pulley and tune, real tuning could give better results but it will probably be very costly since the tuner will have to crack the software to the Jag to unlock it. I still wonder about the fuel pump and injectors though, Mina may cut them off at that point for a reason. with lack of information on them it will be hard to determine for sure if they are keeping it from leaning out or causing other problems due to the overworking of the fuel pump.

 

Mina doesn't supply any type of tune for the pulley. That's just the stock mapping and that's why it does what it does. I've got someone looking into it and will let the forum know when I have some better info.

 

I read several references to "the fuel pump." The 5.0 direct injected engine actually uses three fuel pumps, one standard pressure electric pump at the tank and two ultra high pressure pumps directly driven by the engine. All are computer controlled and can deliver far more fuel at ultra high pressure to the direct injectors than could ever be needed.

 

Taking a look at the air/fuel mixture on the dyno sheet, it is safe to say that the standard XFR is detuned from the factory. It would be interesting to see a similar dyno sheet from the XFR-S and see how the air/fuel mixture compares to the standard XFR.

I am currently running the one-off axleback by GSR Autosport that was made for their test XFR in these articles. It is actually an excellent sounding system and there really is no drone while cruising at freeway speeds.

At wide open throttle, this axleback is actually quite loud; louder than many of the cars (as told to me by spectators) at the recent track day I attended at the Streets of Willow. The car was excellent on the track, however, there are a few areas in which it could use improvement. I probably should have ran the Michelin Pilot Super Sports rather than the very tame Hankook V12 Evo's.

I do plan to install an upper supercharger pulley and have the car tuned in the coming months. After reading about the experiences of a few forum members and the tunes they have ran (ETG, Eurocharged), I am still left with questions pertaining to what has actually been done to the factory mapping to achieve the power increase.

The service manager at my local dealership has agreed to flash the factory engine map from the XFR-S onto my car using IDS/SDD. We are currently researching if the TCU and Differential programming from the XKR-S GT can also be flashed onto my hardware. The reasoning behind my wanting this map is the fact that the XKR-S GT shares the same six speed transmission as my 2011 XFR and I am hoping this will raise the torque limitations for midrange power, raise the governor from the factory 162mph to 186mph, and make the active differential engage earlier to reduce the tendency for the inside tire to spin power away on corner exit.

I feel these flashes along with the pulley and exhaust should provide a safe yet tangible increase in power and performance.