A pulley will bring the peak power on sooner i.e. at somewhat lower revs, but in the top end there wouldn't be so much difference, well that's what we have learnt with the older 4.2L setup anyhow, which actually loses a little power in the top end from a pulley upgrade.

Regarding the torque number from OzXFR's 1st dyno run. Saw a stock F-Type V8S (supposed to be same torque at 625Nm) on a different Dyno Dynamics dyno this morning and it did ~670Nm at the flywheel, so basically the same number as the XFR...

HP/kW from the V8S was a lower number, 414rwhp vs. the 460rwhp seen on the XFR, but the HP figures are never exactly comparable between different dynos...

Looking forward to seeing the after tune numbers from this XFR.

 

A TVS blower on a 5.0 engines will not loose that much on a top end, it's more efficient blower and it's map is still good at a top end. But anyway, the heat may do it's job and there'll be a loss of power.
I suppose thats a calculated torque (OBD-II), it's not very accurate, from what i see in a firmware i'd suppose up to 10% of deviation from a real torque.

 

Bugga!

Post-tune dyno run done this morning and it's all bad news.
It seems I've lost a heap of power.
Here's the chart:




Blue lines are the previous pre-tune run, red lines are this morning's run.

Two problems:
- big dips near the start (around 3,800 RPM) and near the end (around 5,950 RPM), the tuner is not sure of the cause but suspects the ECU is cutting torque for some reason
- running way richer than before throughout the rev range which kills power, AFR drops way down to 10 at around 5,600 RPM and goes even lower, it's just that this dyno doesn't read any lower than that.

I'm now going to get in touch with the tuner and see what can be done to sort this out.

 

Oh no Oz! Don't let my twin sister suffer that way. That chart looks like you gave a 5 year old a good dyno curve (blue) and a red crayon to draw with! I'd get that thing out of there ASAP!

This is the kind of thing that made me seek out a local custom tuner to get mine done. Someone who has a reputation for using his own laptop to actually tune and not just load purchased canned tunes of questionable quality. Mine is tuned for usable power under the curve, not just peak power.

My guys can actually run a dyno as well. They told me a bunch of ways that they're aware of that shops use to inflate their dyno results. They gave me the Winpep files, told me where to download Winpep and said "Have fun playing with the data". I know exactly what I purchased, what it gave me on the "butt dyno" and the real dyno numbers.

I hope you get it straightened out quickly.

 

I'm in.
Just to clarify a things: it's not a "purchased canned tunes of questionable quality", it's a actual XKR-S tune, adopted to run on any Denso ECM in XF/XJ with an AJ133 engine.
This exact tune were installed in XFR before for a forum member Jaguar Forums - Jaguar Enthusiasts Forum - View Profile: raulan
Actually there were some problems with that car too, at first dyno it showed about 300hp and the AFR were terribly wrong.
Cleaning MAF sensors helped a lot, but there still were a bad enough results.
Turned out that the lower O2S were giving a wrong readings (that particular car have cats deleted and had a minicats installed), after removing a minicats the power had raised up. But the actual problem were a I/C circuit water pump, after replacing it the results were good, see an attached pic. Also IIRC there were a few leaks that affected a fuel trims.

OzXFR - To be pretty sure in reasons, causing these conditions i need to run a diag session on a vehicle, it will reveal everything. I'll contact a Cambo to see if he can send you a cable as soon as possible. Also i've sent you a PM with contacts details.

 

ML - I cleaned the MAF sensors the day before the first dyno run, if that helps.

 

My bad . I got your XKR-S tune and another post mixed up. Long day at work yesterday. Still hoping you get everything worked out soon.

 

Wow you lost a LOAD of torque, that is crazy

 

Not a problem
Sure we will. It's not a magic thing, it may take some time to figure out what's wrong, but it's fixable.
Actually there's a lot of failsafe guards in a firmwares, more power=more safeguards (upon looking at a F-type SVR tune i've though i'm nuts, LOL), so if one (or two, or three, e.tc.) parameters are out of normal it may still not trigger a CEL or restricted perfomance, but it may reduce a power a lot. I.e. in a stock tune this conditions may leave a power "as is", but with more powerful tune it may steal a lot of power.
Basicly, we can get more power from an engine by altering a fueling and ignition maps. For example, if the i/c pump runs, but pumps less volume per hour - on a stock tune it may not cause a problem, since the IAT2 readings still remains in a safe region for that a/f and ignition. Add some ignition advance and exactly the same IAT2 may become dangerous and lead to a detonation, so ECM will add a fuel trying to avoid a detonation. Make a few runs (even on a factory tune) at a hot weather, without sufficient air on a intercoolers radiatior - and here you are, lost a power.
Same, for example, for a wrong MAF readings - ECM detects, with a comprehensive monitor, that, according to MAP/TMAP, MAFs readings are wrong. At WOT ECM will add a fuel and retard a spark to be sure that the engine will not fail.
Some leaks on an intake side - again, MAF readings are a mess, let's add some more fuel at WOT.
And there's a lot more in these modern ECMs

 

IDK, it be a shame for you to grenade you AJ133SC while things get "sorted out". Just lucky to have a local tuner to do mine, right tune out the box. Good luck.

 

In a conditions, which are occuring with OzXFRs car, theres no risk to grenade an engine.
It may be easy to hide a things within a tune - like rewrite a tables, so they always be on a stoich or a lean side, yeah. But instead of this i prefer to really investigate a problem and to find a real cause.

 

Bewdy!
Just spent a couple of hours with the tuner (MoscowLeaper) re-doing the tune remotely with the SDD, and this time it's looking good.
Went for a test drive and it's a whole new car, it now goes like the clappers again plus extra.
I need to put 100 to 200 k on it before taking it for another dyno run, will book it in for early next week.
ML explained that the problem was caused by the XKR-S having an X-pipe in the exhaust where the XFR has a resonator instead, and this difference effects exhaust pulses, MAF readings and O2 sensor readings, enough to trigger the ECU to default to a super-rich map.
So he tweaked the XKR-S tune to cater for a resonator rather than an X-pipe.

 

Better but still not right:





The sudden torque reduction has gone, but it's still running way too rich.
Not as bas as before, but still too rich.
I should be getting around 375 - 380 Kw at the wheels, not 335.
The blokes at Morpowa reckon the tuner should easily able to tweak the fuel table to fix this problem and get things to where they should be.
So it's back to the tuner again, lucky I kept all the gear pending this possibility.

 

This type of stuff is what makes people afraid to tune their cars. So wish it would have gone better for you initially and hoping it turns out well in the end.

I feel very fortunate to have found Jailbreak local to me to get a true custom tune. They did a great job and I've never had ANY issues related to the tune.

 

If it was my car, I would likely shop around for another tuner at this point and ditch the XKR-S tune. Assuming +/- 10%-12% drivetrain loss, you're basically close to what the stock power levels for an XFR should be...and from what I read earlier in this thread possibly less. There are several reputable tuners that members on this board have experience with, do a quick search and learn up on them if you haven't already. A lot of them offer mail-order tunes so you don't need to be there in person.

 

I wish I had better things to say but this clip shows my sentiments


(All joking aside...why are these Jags so hard to tune?!?!??!?)

 

Tiny market - almost all owners are simply not interested.

 

Update.
Tried another tune but still no joy, power well down on stock.
Have now, at least for the time being, reverted back to the stock XFR tune.
From discussions with the tuner and others it seems the root cause is the stock XFR exhaust system which has a central muffler followed by a pair of resonators, then the rear exhaust mufflers with the mechanical valves in them.
The XFR-S (and XKR-S) instead have an X-pipe in place of the central muffler, and at least the XFR-S has less restrictive rear mufflers.
In theory the XKR-S tune will not work on my XFR unless I modify the exhaust system to match that of either an XKR-S or and XFR-S.
I have been unable to find any photos of the stock XFR-S exhaust system showing exactly where the X-pipe is, nor have I been able to find any detailed info about the rear mufflers and how they differ from XFR rear muffler, although I suspect they are the same mufflers just with the mechanical valves deleted so that they are in "open" mode all of the time.
I would prefer to retain the existing stock rear mufflers if possible, as I doubt they would contribute much if anything to the XKR-S tune not working. I ran with a set of hi-flo straight through rear mufflers for a couple of months but they were just a bit too noisy and droney for my liking so I swapped back to the stock mufflers, by coincidence a couple of days after the first unsuccessful attempt to install the XKR-S tune.
I've watched/listened to a few videos of the XFR-S exhaust and it seems to me that it would be a bit too loud and droney for my liking, much the same as the straight through mufflers I previously had on.
So I'm thinking that an X-pipe plus stock XFR rear mufflers will give me the best of both worlds, reasonable sound without being too loud and allow the XKR-S tune to stick.
I know some have deleted the valves from the stock mufflers but I would prefer to keep them in.
I would very much appreciate it if someone could post up one or more photos of a dead stock XFR-S exhaust system, in particular the central section showing the X-pipe.

 

Gutted for you but keep going..........ref the exhaust though check out my new post.........very interesting set up inside that center resonator!!!

 

Yes it does appear that all the factory 550PS cars (XKR-S, XFR-S, X351 XJR, F-Type R) have an x-pipe in the exhaust.

Here's the blurb from the XFR-S press release:

"The exhaust system has been optimised in order to channel the waste gases away from the engine with the greatest efficiency. The central silencer has been replaced with an X-piece and near straight-through rear pipes combining to provide an enhanced exhaust note with the added benefit of a motorsport-style crackle on the overrun."

Here's some pics from an XKR-S exhaust, with the X-pipe.





On the XKR-S the x-pipe is more towards the rear, although the rear muffler setup is very different to the sedans.

The F-Type V8S & R exhaust has the x-pipe a but more towards the front.

Have not been able to find pics of the undercarriage of an XFR-S or X351 XJR... and there are no cars close to me to have a look. Anyone?