I was at the dealer getting some service and the rep started telling me how silly powerful the XKR-S is... I happen to think my 510hp gets outrageous too if not careful. Haven't driven the S yet but can't imagine it feeling that much different...

While I don't actually NEED more power. I do wonder what it would take to close the 40hp gap. Have already done Mina. Would not a tune extract the additional 40? And at what cost? Warranty impact?

 

I'll agree with you on the outrageousness of the 510. I'm afraid that the current Power:Weight ratio in my XKR probably outstrips my ability level for now. I'm still being very careful with stomping the throttle.

 

I suspect the 40hp increase in the "S" is attributable to more than just a different crank pulley.
The first thing I would do is a comparison of part numbers for intercoolers. With any increased boost there is increased intake temp, which lessens power. I don't have an XKR, but if I did and were to use the Mina pulley I would increase the intercooler, provided there is room. The 07-09 XKR intercooler part number is C2P012207 at a list price of $1300. A clever hot rodder could commission a larger intercooler for a lot less $$.
The other area of part number comparison might be the supercharger itself.
Eaton, the mfg., has made some changes in recent years. The part number for the '-07-'09 supercharger is AJ8009855 @$2200.
You can even consider a KenneBell supercharger. Check out https://www.jaguarforums.com/forum/p...59/#post243827.

 

The difference by all accounts is in the ECU tune, not hardware, with the 510 hp engine's having more power "limitters" enabled. They have the effect of reducing power to reduce driveline stress, and I suspect to differentiate the 470, 510 and 550 hp models. There's no need to upgrade the dual intercoolers on your 2010 XKR, or the supercharger, but an ECU tune will unlock the extra power if you feel you need or want it. I've had mine on the race track a few times now and it's hard to see that the car needs more power even in that setting as tire grip seems to be the limitting factor, even at stock power levels.

Bruce

 

Funny you should mention the tune. I was talking with the JLR engineer today while he was visiting the shop for another reason and he is driving a VERY early X351 supercharged. You know, the 470 horse motor. He said he has the 550HP tune in it and its a rocket. I asked if it is just the tune and he confirmed. Now, he drives a preproduction car owned by JLRNA, but the evidence is there to support that it is only a tune to change it. Apparently it also work fine with obd monitors and all obd2 related stuff. If the aftermarket has some good tuners out there, they can probably work on it and get it out. I imagine it could work for the Rovers as well although they only use the 510 horse motor and the new RR supposedly will have the 550 horse motor in it.