I had no idea the 5.0 XKR was this quick and fast, just more stuff to add to my XKR obsession! I had the base 2007, 4.2 it was alright but sounded great. I had a chance to drive a 2014 XKR yesterday and was amazed. I found this video series with an XKR against some other cars, 997 turbo etc

Also the prices on the XKR-S are great buy for what was a $133k car, I like the seats, interior, big HP motors, but the rear valance and spoiler are a big gaudy and Japanese drift car looking, the front is also marginal, but in black it's not so noticable.

Anyway, too many choices, I have found some low to no mile XK's, XKR's and also XKR-S's that are such a good buy and value. On top of it, there is not a bad angle to the car lookswise! The M4 etc, has no front overhang and a huge overhang, and even the F-Type looks a bit odd at certain angles and looks like it has no rear end, but it's a great looking rear end. Actually EVERY car looks odd after looking at a Jag XK.

 

If the XKRS is a bit gaudy for your taste, for relatively little investment, you can do the performance upgrades with some tasteful body modifications and have the car you want. (I also preferred the stock body, but wanted and did some modifications) The 5.0L engine really adds a lot of oomph to what was already a good performing car. I've enjoyed taking mine to the track several times, and can't wait to go next weekend with the upper pulley replacement and flash tune.

 

Video of a stock 5.0 xkr vs 4.2 xkr, what a difference, havn't a clue what their saying.

 

I was going to look into that, how much more power can be gained on the 5.0 supercharged XHR to get it to XKR-S power levels? I guess the basics would be a different size pulley and tune, then it probably gets into, exhaust, injectors, sensors etc.

 

The R is 510 HP and the R-S is 550 HP. From some of the discussions it seems that the difference of 40 HP is just a matter of fuel mapping and program update. I assume it's just a matter of plugging in the R-S software into an R but I also assume Jaguar won't do that for you. I don't think there is any difference of the engines. Does anyone know.

 

Talk to the guys at ETG Tuning. They are a sponsor and CA based. They did a tune for me on my 5.0L NA and that plus a Mina exhaust system upped the BHP from 375 to 440 on a dyno. Speak to Jags at (408) 507-0680

 

1960apache,
The 5.0L Jag engine is the same whether in the XKR, XKRS, F-type, XF, or XJ. It is capable of horsepower well in excess of the XKRS' 550hp as in the Project 7 F-type where it is 575hp from the factory. With the tune and pulley swap, and the addition of an
X-pipe to the exhaust, tuners like the one Ralph mentioned above, ETG or Eurocharged, claim between 600-615hp (obviously, in excess to the XKRS' factory specs). This can all be done including parts and labor for less than $2000 (and Eurocharged is selling their tune and pulley package for less than a $1000, but you have to arrange for installation, ETG is about $2000 including install). This is far less expensive than the extra cost of the XKRS and you have equal or greater performance. I chose to slightly modify the body with the side skirts and front splitter from Mina Galleries, and the rear bumper/diffuser from F/X Designs. These cost me about an additional $2500.00, and I had the look I wanted, a little more aggressive than stock XKR, but not as "out" there as the XKRS. By this time next weekend, I should have the tune reflash (had the pulley installed this past week), and the X-pipe done, and will hopefully be on the track at Buttonwillow testing them out. In other words, for about $5000 complete, I will have more than the performance and a different, customized XKR from the stock XKR or XKRS.

Where in California are you?

 

The engine of the XKR and the XKR-S is absolutely the same.

The difference comes from the exhaust (XKR-S has a factory x-pipe) and the ECU program. That is all. Nothing else in the driveline is changed.

Just changing the exhaust to a straight-through the with x-pipe like the factory setup on the XKR-S will make a considerable difference.

A Jaguar dealer won't load the XKR-S tune into your car. But there are others who can.

 

I didnt notice a difference in power getting the x-pipe, but that is because the stock XKR has oodles of power - the biggest problem I have is traction - so while it is quite possible that there has been an increase, it isnt something that translates to the car being quicker in my case.

 

Did you just fit an x-pipe and leave the resonators in place? The XKR-S exhaust is straight through in the center to the x and only has the rear box.

See pics here https://www.jaguarforums.com/forum/x...9/#post1228475

 

Yep, the resonators came out as well. Sounds awesome.

I dont doubt that the car has more power, but ultimately that isnt translated into forward motion, just rubber on the road. But I'm running dunlops on the rear, I understand that other tyres might be better. As it is, the car will wiggle at the back end accelerating hard from 80kph.

 

Out of interest do all the 5.0litres from the XK up have the same basic engine components in terms of pistons and crankshafts?

 

Ah ok, cool. So do you want more power?

The pistons are different between the naturally aspirated and supercharged engines (to change the compression ratio), pretty much everything else is the same, aside from the obvious stuff for s/c vs. n/a.

 

You raise interesting question here. The R is listed with 510 HP so is that with the standard exhaust or the performance active exhaust ? If the standard exhaust does it have less HP from the 510 or does the PAE have more HP then the 510. Is the only difference from an R with PAE and an R-S just a fuel remap. So , if you just get an aftermarket tune without a pulley change how much HP gain would you get with a R with PAE. Just wondering

 

Well let's be clear, it's not 510HP it's 510PS, there is a difference between Pferdestärke and Horsepower.

The factory ratings are:

XKR, 510PS, 503hp, 625Nm, 461lb-ft
XKR-S, 550PS, 542hp, 680Nm, 502lb-ft

I believe the rating of the XKR would be with the standard exhaust. I think the cars with the performance exhaust will have more power, but exactly how much I couldn't guess.

Yes it's just the ECU file.

Well you don't have to have the factory performance exhaust, just something that is equivalent in design (i.e. x-pipe, free-flowing). I don't think the active muffler makes all that much difference to the numbers; a forum member here in Sydney did some dyno runs with the valves locked open and closed, there was no noticeable difference to the outright numbers, although that was on a 4.2L car.

As for tunes without pulleys. Well if you have the right exhaust then flashing the factory XKR-S tune is certainly possible. Aftermarket tunes without pulley (but again with the right exhaust) then maybe another 50hp on top of the XKR-S numbers. The tuner I work with has a tune that is "close to 600hp" without pulley.

I wouldn't try any tune on an XKR unless the exhaust has been done as per the XKR-S with the x-pipe, like the pics in that other thread.

 

This seems to be an interesting play on numbers as in the US the HP is listed at 510 or 550 and I see in other countries they use PS. Must be a marketing ploy over here. As for the conversion I am not familiar with PS to HP so how is PS measured and what is the conversion factor . The NM to LB FT is a standard conversion but I'm not sure of the PS to HP. By the way my window sticker for my 2012 XKR lists it at 510 HP, funny.

 

Once upon a time water was pumped out of deep mines using horses...
When Mr J Watt built a steam engine to do the job he needed to compare it to the equivalent work done by a horse, hence the HP, since this was in England the units were pounds of water raised in feet in time units of hrs-mins-secs.
Obviously not very accurate; I believe they came up with 33,000lbs up 1 foot in 1 minute... (461lb-ft is the same as lifting 461lbs up 1 foot)
In the metric system this would not convert to "nice" numbers when measured in kgs and meters, so they would have come up with a "close" formula to calculate HP or PS(metric hp), the relationship between them will always be the same as they will both be calculated values from torque, which is what any dyno actually measures.
USA is likely the main imperial country now, most of the world has gone metric, in Canada we are all mixed up and buy beer in 341ml cans (12ozs!!)
HP is basically just T x rpm.
Imp hp = 2 x pye x rpm x T / 33,000 which is why T and HP always have the same numerical value at 5251rpm in imperial units. (from memory 50yrs ago...)
It can be reported in kWs. imperial hp approx 746W and PS approx 735 I think.
Something to think about??
Hope I hav e this right..
Regards

 

Hi cambo,

Would you mind leading me to the thread where this experiment is discussed ? I am interested in reading more about this as I always asked myself the same question
.
Thanks !

 

I don't think there was a thread on it. We talked about it over the phone as I recall...

We'll be meeting up this week maybe there will be more info to share then.

 

Ok, thanks in advance, I'd really appreciate to know more if possible...