performance upgrades
 

Looking for performance upgrades for my 2002 xkr

Hot Rodding An XKR Advice And Sources
 

I’ve been down a long path in the attempt to significantly improve performance of this car. The two things that will advance you the farthest is a lower rear end with Posi-Track/Track Lock. Second is either a twin-screw supercharger or a LS conversion. Your car may be too new for the LS conversion (I think the cut off is 2001 but you can contact Jaguar Specialties to confirm.

My car was also too new to do the rear end change (mine is a 2004 and the ECU reprogramming too untested for me, didn’t want to end up with a bricked car). The advantage to the LS conversion is, once done, it opens up a ton of performance upgrades and service help in the US that you don’t have with the stock engine. The advantage to the Twin Screw is the car remains largely stock and you get to higher performance more quickly but there are far fewer folks that know how to work on the result. Avos here on the forum is arguably the leading expert of this latter path, I think his car puts out something like 650HP.

Of course, before you start, make sure your brakes are good as you don’t want something that goes quick and can’t stop well. I’d also check your suspension and steering bushings and bearings (not to mention making sure your tires aren’t too old or lack tread) because avoiding an accident should also be a high priority. In the end though, this car really was never intended to be a hot rod. If you really want to hot rod something you might consider starting with a different car.

Our cars are really designed to be performance-oriented cruisers, they eat up the miles and have enough to pass when you really need it. Things can get really expensive really quickly if you take a vehicle designed for one thing and try to turn it into another. One final piece of advice, for whatever it is worth, get a firm idea what you want to do, fully price it out including labor, then add that to what your car is worth, and both decide if you really want to spend that much and whether another car might be a better choice.

Performance upgrades generally don’t add to the value of the car and you can spend an impressive amount of money. (And then end up hoping your spouse never finds out). Here are a number of links with sources, first are videos of XKs with significant performance upgrades followed by a number of performance vendors (you’ll also find threads in this forum that pretty much cover anything you can think of) the last thread is my own build thread:

https://www.bing.com/videos/search?q...45BD&FORM=VIRE

https://www.bing.com/videos/search?q...E46F&FORM=VIRE

https://www.bing.com/videos/search?q...D&&FORM=VRDGAR



https://eurotoysltd.com/

Jaguar Specialties

Paragon Design UK - Jaguar XK8 XKR Body & Engine Modification Specialist

https://www.arden.de/en/refinement/j...xkr-1996-2005/

https://www.pistonheads.com/gassing/topic.asp?t=1393274 https://powerflexusa.com/xk8-xk8r1997.aspx

https://www.jaguarforums.com/forum/x...project-82601/

Good luck!

+1 XKR is a really a GT car, not a track day wonder - you can make it one if money is no object, but there are better starting points

+1 agree that best to start is to check everything works as it should, is clean (radiators etc.), and not worn out (suspension likely will need attention at least), and maintenance items done (fuel filter etc.) - fuel system, cooling/intercooling system, brakes, suspension, etc.

For power, somewhat on the budget side you could look at replacing the intake with something larger since it is restrictive (fashion something using 3-4 inch silicone intakes stuff, ensure cool air intake) - lots of into on the forum, you can also bore the throttle body a bit bigger (Maxbore). Also water-meth injection. And upgraded intercooler pump - opinions vary on intercooler radiator upgrades - i.e. more surface area is probably good, thickness maybe needs more consideration. You can also spin the Eaton supercharger faster with pulley upgrades (lower and/or upper), and try and port it, but how much more power you get is a subject of much spirited debate, versus possibly moving the power band to lower revs and generating enormous amounts of power-sapping heat that requires more measures to try and get rid of.....plenty of good reading material on the forum on this as well.
Maybe lowered springs, although can be tricky not to upset other aspects, and then ideally better/stiffer shocks but then no longer a budget item

On the non-budget side (i.e. you can easily spend much more than you did to get the car...),
- twin screw supercharger such as Kenne-Bell, although I believe Avos is no longer selling kits, so you would need to find alternative option
- limited slip diff - Quaife or OS Giken
- axle ratio change and TCM reprogram
- cooling the intercoolers with the Aircon system - Killerchiller etc.
- Brembo brake upgrade (if you don't have already)
- 200 cell catalytic converters
- springs/shocks/suspension bushings/rear anti roll bar, etc.
- etc.