So as some of you may know, I recently upgraded my 2012 XFR and purchased a 2015 XFR-S.

And I posted my initial impressions in that post, from about 2-3 weeks ago...

I have been driving the XFR-S everyday (since I picked it up), and I couldn't shake the feeling that the car is just such a monster compared to my tuned XFR... After all my car was making over 500+whp after the tune 490+ lbft of torque at the wheels. I documented the whole process in this thread:

https://www.jaguarforums.com/forum/x...tuning-109281/


So I called up the same dyno shop, and made an appointment, today was my dyno session on my 100% stock 2015 XFR-S... I will let the results speak for themselves...

All I have for now is scans of the printouts, I will update once I get the digital copies emailed to me.

Here are two runs from today, for 2015 XFR-S (~1,500kms or ~900 miles on odometer):



I am going to refer to the lower of the two numbers 532.7WHP and I will use a conservative 10% for drive train losses in lieu of their automatically generated number, and I get ~592HP


I had him overlap this run with my 2012 XFR runs (from over a year ago), and here are some fun comparisons...


2012 XFR (red line in graph below) vs 2015 XFR-S (light green line in graph below):


Again using a conservative 10% drive-train losses in lieu of their automatically generated number, I get:
455.3/ 0.9 = ~506HP (very close to the XFR's stock rated figure of 510HP)
532.7/ 0.9 = ~592 (not close (at all) to the XFR-S rated figure of 550HP)

That's a difference of: ~86 Crank HP or ~77WHP (that is a huge difference)


Same goes for torque: 501 lb-ft vs 456lb-ft of the twisty stuff at the wheels... difference of 45+ ft-lbs at the wheels



And then I had him overlap today's dyno run (light green line) over top of the progress of my 2012 XFR, that shows all the stages:
Stock (Red line in chart below)
Pulley and Exhaust (dark blue line in chart below)
Pulley, exhaust and RICA Tune (light blue line in chart below)...



The results are staggering:



If you look at the four (4) overlapping runs above, and focus on the runs from 2500 to 5500rpm, you can see the light green is clearly head and shoulders above the best of the previous runs.

In fact its not till you analyze it further that you realize, that other than a freak upswing in torque and power (for the light blue line only) at ~5700 - 5800rpm and progresses all the way till ~6500rpm, that the clear winner should be the light green, which has more area under the curve clearly shown by the Average HP (in the chart above).


I don't know about you but on power figures alone I am blown away by what the XFR-S is putting down...

I can finally start to make sense of why this thing is seemingly scaring the crap out of me, it is because it is ridiculously underrated by the manufacturer (unless I got the one odd one that is just a freak)...

 

Thanks for sharing! That's certainly going to get people talking

 

Wow, that is impressive! I need to get mine (stock RS) dyno'd to compare.
It'd be great if you could run it at the track -- that will show real power to the ground.

 

I was hoping you were going to jump in here. Patrick813 and I are going to Famoso on the 31st and we will have time slips for you to run calculations on. I know how you love doing that

I agree, you definitely need to dyno yours for comparison. I think it was done on a Mustang dyno. Ahmad, is that right? If so, try to find one in your area to take some of the variables out.

 

Glad to share with the community, and I figured it would get people talking...

I would love to take mine to a track, but there is nothing close by/ local to me, at least 2.5 hrs each way, so 5-6hrs of driving only to spend ~2-3 hrs on the track, hasn't tempted me yet... besides since I live in the great white north (Alberta, Canada) most tracks are shut down for the season... The soonest I would be heading down would probably be next spring (May, 2016).

For comparison, you should get yours on a dyno... I could swear the car I currently own, seems noticeably faster than the one I test drove...

Best of luck at the track... and for the record its a Dynocom Dyno. Shop's website (specifically their dyno page):
Calgary Autoworks - Tuning | Service | Parts. Dyno Service

 

The difference is unbelievable!!!! I really think there is little point in trying to convert dyno results to a meaningfull power figure..........just too many variables in drivetrain and the dyno itself.
..
What undeniable though is the power difference on the same rig and youre tuned XFR and the XF RS..........now what i would really love to see is a video of youre cars dash and it running from 0-100mph........i've just recorded my le-mans XFR and got 4 seconds 50-90.......50-110 7 secs........

 

Way too much time in the laboratory for me! Drive it, pick up beautiful women and live happily ever after!!!

 

Excellent!

 

Do u have any idea what boost the XF RS runs compared to a stock and pulleyed XFR??? really interested to know how the extra power is being generated.......if they run a stock XFR size pulley and generate 550hp..........+600 should easily be achieveable with a smaller pulley and map

 

First... the only thing that will make a supercharger make more peak boost is a pulley upgrade. if we are comparing stock pulley to stock pulley, then boost will be the same. A tune will not increase boost, like it can in turbo charged cars. Superchargers generate their boost based on the drive mechanism, pulley and belt. the only way you spin the supercharger faster, is by revving higher or installing a smaller pulley to spin the supercharger faster... Turbo Charged cars utilize exhaust gas to spin the turbo. A pneumatically driven actuator opens or closes the turbo waste gate (most stock vehicles will have internal waste-gates, meaning it is built right into the turbo, hot-side housing). A tune on a turbo charged vehicle can limit how soon and how frequently the waste-gate actuator opens, yielding more boost. The tune will also likely touch other operating parameters: fueling, ignition, in relation to load. On supercharged cars, you can still tune a car more aggressively to extract more out of it at the same mechanical boost limits. I am sure there is a bleed valve that will effectively act as a bypass to the supercharger that will limit how much boost the supercharger can make.


Secondly... the purpose of my thread is to point out that Jaguar has under rated the XFR-S, and any other Jaguars that are claimed to be 550HP (a lot of manufacturer's do this). Even a tuned XFR with a pulley, that is claimed to be ~600BHP, depending on the source, for example:
ETG, see link:
https://www.jaguarforums.com/forum/x...upgrade-64595/

I tried looking at Eurocharged's website, but I couldn't bring myself to post their link, and I will stop there so I do not go on a tangent.

All tuning companies, its in their best interest to claim the most they can, while still remaining realistic...

600BHP, based on a very conservative drive-train losses, I normally use 10% for RWD, but some go as high as 15% for RWD, again these are estimates, this isn't an exact science. This would mean that this 600BHP car should register 510 to 540whp on a dyno (depending on what losses you have factored for, 15% and 10% respectively).

So its not that hard to claim 600HP, at this point once you start tuning, you can claim your measured whp, but the moment you start converting that to crank/ brake horsepower that is all you will be doing, is estimating.

For ***** and giggles here is a link of a Hennessey F-Type:

Everyone knows the FType R, is 550HP, and they claim it now makes 623HP, it also made 518WHP... according to my math, that's a drive train loss of: ~16.85% which is close to 15% but still a little on the high side... Everyone has their marketing putting out numbers that they have to be able to back up one way or another... What would make this a whole lot more informative is a before dyno, that shows what the 550 actually put down stock... there's an old tuner's trick where you take your stock whp measured at the dyno and divide that by your manufacturer advertised HP number (you now have a ratio that correlates to your drive train losses). Now when you measure your new tuned/ upgraded WHP numbers you simply take the newly measured WHP and divide by this ratio. and you have your estimated crank hp number.
For example: If I have a car that claims 500BHP and I measure on my dyno 400WP. 400/500 = 0.8 (or 20% drivetrain losses). I tune this car and it now measures 450whp so I can estimate what it's BHP is by: 450/0.8 = 562.5BHP, or a gain of 50whp or 62.5 BHP.

Auto manufacturer's under rate their engines (BMW, Mercedes, Audi, and now Jaguar...) and I do not know the reasoning behind this... some parts of the world this might impact insurance rates, I presume?

On the other hand tuning companies will advertise the best the numbers they possible can, because its in their best interest to do so...



The part that amazes me is, a stock XFR-S put down higher torque and higher hp figures than a tuned XFR with a pulley. The biggest question is, does Jaguar install a smaller pulley on the XFR-S? I can measure this when I get home later today...

Because what would be truly amazing is, if they are able to do this with the same engine and supercharger and pulley.

We already know they make revisions to the exhaust, but what if there are other changes to the engine, or the supercharger...

Do we know that they are using the same injectors in both engines?
Are there any slight modifications to the supercharger itself?
Are there any slight modifications to the engine internals?

 

Great points.............so did you measure boost on youre dyno run?? Guessing not.........

So lets hope you have a stock XFR size pulley!!! Think u may be the first to tune an XF RS on the forum them??? Or is it that they allready have what is in effect a pulley re-map and exhaust?? In other words they are already maxed out.

Cheers fella

 

According to the parts catalogue no, it's the exact same supercharger on all 5.0L engines.

The exhaust of the XFR-S has a factory fitted x-pipe, same as all the other 550PS Jaguar models. But the engine is the same as the 510PS, 495PS, 470PS models.

Same injectors.
None, same p/n for all 5.0L models
None, same engine internals for all 5.0L models.

Aside from the x-pipe in the 550PS models, the only difference is the ECU file flashed to the car. Oh and the ECU's on the 550PS models have an external cooling fan fitted to help keep the ECU cool.

It's been understood for some time now, that the output of the engine is limited by the throttle position. The engine gets throttled back by the ECU on the lower-power models. The "tunes" aren't changing the fuel/spark (you can see in other threads about tunes & pulleys that the AFR's were basically the same before/after the tune) the tune itself is just raising those limiters to allow more throttle.

The x-pipe in the R-S exhaust makes a big difference. Some of you might recall a thread on the forum recently where a stock XFR was flashed with the R-S tune and it was running rich and not making more power. That car had the stock exhaust without the x-pipe, which restricts the breathing enough for the higher-power tune to not work.

 

H. Jones,
The stock XFR that Cambo refers to above is my car.
I'm desperately after a photo of the stock XFR-S central exhaust system, showing the shape and placement of the X-pipe, and whether it replaces both the central muffler and resonator(s) in the XFR system or just the central muffler. I'm pretty sure it replaces just the muffler and the resonator is still there (unlike an XKR-S which has just an X-pipe and no central muffler or resonator), but I need to double check.
Could you do me a huuuuge favour and post up a pic of your central exhaust system?

 

I understand that the XFR-S also has a different torque converter...

Is it possible that the XFR-S is just transmitting more of its Crank HP to the wheels... i.e. losing less through drivetrain loss.

 

There is no specific XFR-S torque converter listed in the parts catalogue, same torque converter for all 5.0L supercharged variants, EXCEPT there is a different one for the 6-speed and the 8-speed models, that's not related to engine output though.

Same for the XK's and XJ's too.

 

I am 99% sure the XF RS exhaust also looses the center resonator..........having stripped one down (see one of my previous posts) its definately disturbing smooth exhaust flow.......i am actually just finishing welding up straight through pipes on a spare center section i have which will then remove the center resonator......as i have a base line dyno run i will then get another run down post delete.........next step for me will be a "H" pipe......looks like these engines REALLY benefit from exhaust scavenging......

 

I did not measure boost on any of my runs, I have yet to see a dyno run for our 5.0 SC engines that has run boost. And I do not know how you could measure and plot this, unless the dyno was able to plot the info as its being generated off of the OBD II port.



Thanks Cambo, that his great info...

Actually in regards to your comment on AFR, I noticed that with some of the tunes but when it came to my tune from RICA (on my previous XFR), there is a noticeable difference if you look at the before and after dyno, here is the dyno for my previous XFR with all three runs overlapping:
- Stock XFR (no AFR measurment) - Yellow Line
- XFR with Pulley and Exhaust - Light Blue Line
- XFR with Pulley and Exhaust, with Tune - Green Line


As you look at the lower graph, the stock tune, anything after 5200rpm the AFR start to richen up, anything richer than 11.5 is too rich in my opinion, and we actually drop into the 10's past 6000rpm. With the RICA Tune we are almost holding a solid 12.4 - 12.5.

And I noticed this eventually helped with my day to day mileage (fuel consumption), was much better post tune.


I wish I had known about this on Saturday, as I just swapped over my winter wheels... and had the car elevated enough to get underneath and take photos of the exhaust. I am not making any promises, but I will aim to do this, but it won't happen till the weekend...

Actually that was something I was curious about...


What would be really interesting is to see if an 8 speed XFR so anything 2013 and newer has a done a dyno... mine was a 2012, so a 6 speed.


If you can take pics of your work, then you would save me of having to lift my car again...

 

Keep up the great work, fellas. I haven't done much to my car in a while, since I figured I'd done about everything I could do to it within reason (and also bought a new house that's getting all of my love), but this thread is getting me re-invigorated. I've been tempted to "upgrade" on a few whims, but really can't justify the ROI of getting something else at this point, as my '11 XFR has been phenomenal and it's only got 35K miles on it (so service is still free and I've still got warranty coverage). A new performance project might be just the thing she needs...

So I can better understand some of the questions being asked, and make sure I'm on the same page, when you're referring to the "central muffler and resonator(s)," which may or may not be different from the XFR to the XFR-S, can you please help me understand to which units you're referring? I replaced what I'd possibly ignorantly call the the rear central resonator on mine with an X-pipe, but I left the front resonator in place, as an attempt to limit in-cabin drone and excessive vibration (prior to ever experiencing any, which I never have). Downflow of the the X-pipe, I added RRP remote cutouts (which I recently upgraded to their Patriot series after the tech jokers at the dealership burnt out the motors in my previous cutouts by treating my car like their personal toy by trying to see how everything worked, while it was in the shop for something completely unrelated). I left the stock rear mufflers and tailpipes in place, but painted the exhaust tips black. I drive with the cutouts open 99% of the time.

Also, if I remember correctly, I originally replaced the rear central resonator with an un-shieded X-Pipe, but thought it was too loud while at the shop, so I changed it out to a Magnaflow X-Pipe muffler.

I've always loved my setup, but you guys have me contemplating getting more aggressive with everything. Most people would tell you that my car is fairly loud with the cutouts open, but I love it the sound and have gotten completely used to it, so might consider straight-piping the front central resonator or going back to the un-shielded X-Pipe. I'd looked into a Cats swap a long time ago, but think I found that the gains weren't worth the trouble, so I'm really interested to see how this thread plays out.

Lastly, for what it's worth, a change in torque delivery being somehow different on the XFR-S vs. the XFR seems like a plausible theory. I remember several years ago, BigCat09, who was extremely knowledgeable and tested everything thoroughly on his own car, but has since sold his XFR and moved onto other cars, was very adamant that, "the tranny ECU is what separates them all by limiting the output." I found that quote in one of the other threads, but I distinctly remember him telling me directly on several occasions that he thought that torque management was the key to increased performance beyond the "standard" intake, pulley, exhaust, ECU upgrades on the XFR. Just a thought.

Side note: I included some of the pix of the rear central resonator exhaust work that was done on my car back in 2012. Sorry for the quality - phone cameras weren't as good as they are now.

 

Thanks for the pics. Still need to get some of the factory XFR-S system though...

I'm not so sure about this. Here's some info.

The 6-speed 5.0L cars run the ZF 6HP28 transmission
The 8-speed 5.0L cars run the ZF 8HP70 transmission

Both are rated for 700Nm torque, according to ZF specifications

There was no 550PS 6-speed XF, but the XKR-S had the same output (on paper) 550PS / 680Nm as the 8-speed XFR-S. Although the engine management systems are different (Denso on the 6-speeds, Bosch on the 8-speeds).

There was talk on this forum claiming that the XKR-S got a "stronger beefed up" torque converter over the earlier cars. But the parts catalogue has no evidence of this at all. Same part for all 5.0L S/C models

And as for different TCM files between the 510PS and 550PS vehicles I thought this had already been answered but I can't find it now so I will ask again one more time just to put it to bed.

 

Thanks for that.

First, here's a schematic of the stock XFR exhaust system, from the workshop manual:




It clearly shows a central muffler followed by a resonator. I've had a good look at my system and this in an accurate representation.

Second, a pic of a newish XFR-S showing the resonator, but unfortunately not showing any detail of the exhaust upstream from that (which is the bit I'm trying to find a pic of!):



Third, a pic of the resonator cut open, showing that it is in fact a twin pipe resonator: