I suspect few XJ6 in the USA get driven in a sporty fashion, but mine does. The car was purchased from original owner (Dad) so I feel compelled to keep it forever rather than sell and take a risk on an XJR.

Driving aggressively around turns demonstrated a charming oversteer tendency that I reduced by having a rear anti sway bar installed from an XJR (thank you Jaguar Heaven and advice from JapThug). Now that I am used to it, my mechanic is OK to consider adding Andy front Droplinks and or steering rack from XJR. However, the most compelling modification for my city driving and tight canyon roads is simply getting a rebuilt rear end from Coventry West with a 4.01 rear ratio in the Jag PowerLok LSD vs my perfectly working 3.58 open differential.

Anyone else having fun with their XJ6 for sport driving?

Thoughts about proactive maintenance?

My 3 carefully chosen future modification choices?

 

Haha there's more than one! I am in the same boat and acquired mine from a family member and am all about the performance driving but like the sedan's size of my "Shaguar". I want to do the rear sway bar add on from the XJR as well with the cross tube brace as well. I would say next would be to replace the rubber bushings throughout in order to tighten it up. Next step is go with Bilstein or Koni shocks. Bilstein is cheaper, I have the Touring Class shocks, ideally I would have gone Koni to sport it up a bit more. Your tires are also going to have a big impact as well as lowering with H&R springs (you lose camber adjustability in front which could wear the inside edge of tires more aggresively).

What is the 4.01 diff going to gain? The LSD factor? Would that increase or decrease RPM at highway speed?

 

It's my wifes car, but I do like to drive it as well. After replacing bushings and putting Bilsteins all around this made it handle much better. I would consider lowering carefully, in a moment of stupidity, I put 215/45/16's on and I scrapped every driveway that had a slight elevation. Also, it didn't look good because the wheelwells looked too big. I went back to the 225/60/16's and it handles nicely again. I do keep the tires at 34/35 psi.

 

Sounds good, I would start with a set of sport or XJR springs and apropriate damping, I am considering GAZ adjustables on my XJR as they are used by some of the racers and cheaper than Bilstiens, plus may be able to adjust front/rear handling balance.
Personally I would not go for lowering springs - may look good but inpractical unles you have perfect roads and will mess up the geometry and probably be too harsh and spoil the car. My old 3.2 sport handled well with the standard sport setup without compromising the Jaguar character. In my opinion, the 225/55/16 wheels /tyres worked better than the 255/45/17 setup on my XJR in terms of handling, I have even considered swapping but like the look of the original XJR wheels.
I am in the process of rebuilding the front end with superflex poly bushes, so will let you know when I finally test them out.
I also have a spare 3.2 rear end with the 4.1:1 gears so on the list to try fitting that with an LSD to my XJR which has a 3.27:1 as stock. A big heavy job so not happened yet, but would really liven up the car.