A different (and less informed) thought: is it possible that part of this is just the design?
I've only driven an 08 twice, and never above, say, 80, but it did feel a little "floaty" on road undulations at speed. ON the other hand, it was more comfy and insulated from the road at 30-60 mph, so maybe that's part of the tradeoff?
I sometimes think my '10 xkr is too stiff and "feel every crack" in normal mode. Wouldn't mind if it was a little softer at lower speeds around town but then one can't have everything.

 

It rides great but I've never owned a european car that floats around...even my old customers bentlys had more composure, I'm certain something isn't working as designed.
wj

 

The Adaptive Dynamics (suspension) is quite sophisticated and is intended to provide both a cushy ride and stiffness for performance by modulating valves in the dampers/shocks.
Although the system defaults to "stiff" under error conditions, there are failure modes under which the stiff response may not be available.

 

Hi There - I have a 2007 XKR Super Charged and I recently did the same trip - agreeably some roads are rather poorly maintained.
The XKR I have performs very well and does not have any of those issues. this one has 47k miles on it.
I was able to get a Service maintenance manual for around $20 on CD from Ebay,
Sounds like there may either be senors or depending on mileage strut issues.
Please indicate how many miles are on car and the history of it if you have that.

 

90K miles, old records do not indicate issues with handling.
I assume original shocks...will check this all out in several weeks when I refinish wheels, replace brake rotors/pads. Can scan with foxwell but will wait until I'm into it and getting dirty.
but as steve_k_xk said, 'The xk springs are terrible definitely not designed for 'spirited' driving very very floaty.

The xkr springs are a lot firmer and the xkrs are firmer once again also with a 10mm drop'

so comparing your xkr to my xk might not really tell us much more than I need an xkr.

wj

 

oh right yeah I recall seeing a you tube on XK and XKR and handling was one of the drawbacks.
the XKR albeit better is still not as good as it could be.
I had a 1997 SC400 V8 jz engine and barely noticed the curves handled like it was on rails - I also sold the car because you could not feel the curves and handled like it was on rails LOL aka high speed driving without feeling like its high speed driving.. like to have some road response to feel connected
The Jag XKR - SC does pretty well
so it could be the suspension is just not as dialed in...

 

I have a 2014 XK that hugs the road at any speed (at least any speed I've taken her to - 128) Not sure if there's a big difference between the 08' and 14' but I had an 05' that wallowed when driven at high speed.

 

I'm not sure you can compare the 10+ models with the 07-09 with any degree of certainty, they have different suspension controls etc.
Not that this really matters much but my 2005 xk8 does not wallow and bounce as much as this 2008 xk. The 2008 is a much nicer car however and the 2008 goes exactly where pointed, I had to learn how to coax the xk8 to go 'exactly' where I wanted. The xk8 has traditional shocks, not cats.
Time will tell and I will share my discoveries as they come.
wj

 

w​

Yes the 2010 has a totally different CATS system with multiple levels of adjustments whilst on the fly by contrast the CATS system in the 4.2 is very primitive with it adjusting between only two settings either firm or soft .

​​​​​​​Also I do recall reading that the xk 5.0 has a firmer spring rate closer to the spring rate of the older 4.2 xkr (07-09) no wonder the newer 5.0 can hug the corners 👌

 

I bought my 2007 XK Convertible with 10K miles and it was solid and in control at any speed...very tight on curves too. Since the XK is faster than most Ferraris that were on the road when I was a kid, it's more than fast enough for me. I decided that the extra $$$ for the XKR just wasn't a good investment for me.

 

getting back on track
1. have you had all bushings checked. And the retaining bolts, of course. All my Jags like eating ALL bushings.
2. have you had your dampers checked. completely, right from the isolator down.
3. silly to ask, I know: are you tires properly inflated. The number of times I’ve seen…
4. another silly one: what size and make of tires.

Once you have established the proper baseline for the car, then we can accurately determine if its the right setup for you THEN go down the path of customization to fit your preferences.

 

I had a facelift 2003 XK8, fantastic, classic. comfortable GT roadster as was the XKR at the time. When the X150 came out and I had an XK for a few days test drive, there was no comparison in handling, it was night and day, the X150 felt to be a true sports in every way and I quickly traded the XK8 for a short term lease on the 2008 XK. I loved it so much but soon wanted even more performance and power from this amazing chassis and took on the XKR coupe which I still have. Point is you say your XK8 handles better than the X150 and which tells me something's off as there's been so many comparisons here and elsewhere over the years since its introduction and no one's said the X100 handled better than the X150, ever.

 

Well life has gotten in the way of my auto passion but…

I did install new tires all around and new rotors/calipers.

(and an alternator, that was fun!)

While crawling around the car I noticed that the shocks are weeping, so they will be replaced soon (along with the springs). There is one bushing that shows signs or wear, I’ll replace all the bushings in the control arms when I have time. All the remaining suspension and steering hardware appears to be in good shape.

What I did discover after having driven the car several hundred miles is that it has a dual personality.

I have confirmed this with many, many A-B comparisons!!!

In D mode:

Over higher speed (70-90) sweepers the car will bounce twice (undulations in the road surface) while leaning quite a lot

Or in DS mode:

Over the same sweepers at the same speed (but different gear/rpm) the car is much better dampened and does not lean nearly as much…it feels just great.



I have read all I can find and the consensus is that selecting DS does NOT affect the shock settings, well in my 2008 base x150 convertible there is absolutely no question that in fact there is a change.

Possibly by selecting DS the threshold for changing the shock setting (hard/soft) is different but without a doubt I can fling the car into tight turns with aplomb and composure in DS mode where in D mode I would be floating and bobbing.



Will report back after new shocks/springs etc. in a month or so.

 

You mentioned that the gear/rpm values were different. Perhaps that is affecting the damper values, if the DS setting alone doesn’t.

 

In my car ( 2007 XK 4.2 Convertible ) the mechanic, which inspected it, said >if< the ( front ) dampers go, it will be expensive, since they are adjustable ... so I presume, they will change with D / S settings.

Hermann

 

yes possibly but when in DS the auto generally is in a lower gear at a higher rpm than when in D...so one has affect on the other. What ever.
I'm satisfied for now but definitely want a bit more sporty spring or much harder roll bar bushings.
wj

 

Hi, if you are planning on changing the dampers you must ascertain what damper you have fitted to the vehicle as earlier cars had a bit of a mix. The best way is to do a resistance check on the solenoid coil in the damper, it's really easy to do on the front just pull the damper plug off and use a multimeter. Early cars will measure around 5.5 Ohms with later cars measuring 2.6 Ohms. The dampers are not interchangeable despite what any parts supplier ascertains, if you fit the later dampers on an early car the ride is super stiff and makes the car undrivable (ask me how I know). Unfortunately to get the earlier dampers new is virtually impossible so you will have to try and find some good used items which is becoming very difficult or get your old ones refurbished. The part number on the damper will probably be Front 6W83 18045 BA and Rear 8W83 18080 AB the AB and BA suffix is very important as any other suffix letter will not work on your vehicle.
I spent months trying to sort this problem out and it cost £hundreds with garage bills and wheel alignments. New bushes, better tyres and slightly increased tyre pressures sorted my slightly floaty vague handling but at the end of the day it is a Convertible Boulevard Grand Tourer after all.

 

Thank you for that information. That last line is probably what I need to take to heart, "but at the end of the day it is a Convertible Boulevard Grand Tourer after all"

wj

 

I wasn't a fan of the handling on my XK. Had way too much bump steer. Too stiffly sprung and not up to par considering how beautiful the wishbones are. Handling and steering feel are the two lowest point on the XK, IMO. Compare the XK to a Vantage, Evora, or GranTurismo's handling and XK is sub par. Maybe there is an aftermarket solution available?

I haven't driven the 5.0 XKR's, so maybe things had improved. I believe they did.