They are not the same, one is for a car with CATS, the other is for a car without.
You will need to check what you have now.

 

CATS?

 

Which is the best option for me? There is no electrical connection on the shock mounts. Also I have found a touring class and heavy duty. which are stock on the XJR

 

These:
24-023726

 

I want my cars ride/handling to be like an E39 M5. Its not as far fetched as one might think. I work with a ride and handling vehicle dynamics expert and he says the weight distribution is good on our cars and the suspension geometry- so its primarily a case of matching the wheel rates.
I like the damper rates of the older Straight six 'R' variants- a little stiffer than our X308 Rs. Unfortunately the older X306 dampers have a different fixture at the front than the X308s. Springs can be tailor made.

 

Don’t waste your time with KYB. Just did this and they lasted about 5k miles. I just had to replace and went Bilstein on rear with new spring isolators. Can’t wait to change front ones too!

 

This is, unfortunately, not the first time I read about KYB and its very short life on our Jaguars .
I's the reason I went Bilstein too.

 

Went w/ Sensen shocks here, zero complaints.

 

That's cause your car is in the transmission shop for a decade by now ...

 

Albeit it rode much better in the miles prior to that lol.

 

Generally, it is very important to match the shocks to the spring rate, for the best ride and handling. The best matched shocks should be the oem ones, in this case Bilstein. They also happen to be the best quality around, pretty much. Very, very durable, in my experience.

 

It's not going to handle like an E39, and you'll ruin it trying. That's OK, because the E39 ride is shockingly poor compared to the Jag. Your best bet is to restore the Jag to its original ride and handling - by replacing worn components. That begins with a careful examination of all the suspension components.

Does your ride and handling dynamics expert appreciate that the BMW is a 20 year newer design with tubular welded aluminum sub frames and sophisticated multi link front and rear suspension?

 

My friend disagrees with you. What's your background? I'm assuming you've worked for an OEM and have been involved in vehicle dynamics and ride and handling of several vehicles?


My friend has been involved in several OEM platforms and used to work for Pro-Drive.


He's a BMW nut like me and currently drives an XF. The control a multi link gives over a double wishbone set up is certainly better but its 'fine tuning' at best- the main points are that the weight distribution is similar (52:48) and some of the key chassis dimensions aren't a mile away.

 

Bilsteins is the way to go. If you go to jaguar they will sell you the Bilsteins but for almost triple the price. Go to amazon and the Bilsteins are $100. If you own the Supercharged R varient of the XJ then go with the green sport shocks because they go with the sport spring. If you have the XJ8, VDP or L get the Black comfort standard shocks. If you put Sport shocks on the standard suspension the ride is going to be rough because of the Comfort springs.

 

No, weight distribution is only one factor. The first, and most important one, the foundation if you will, is structural stiffness. Without it you won't get a great handling car. It's something that is now 3 generations improved on an XF. The X308 structure was designed in the EARLY 80s. At the time, they did a good job. Now, it's ancient. I'm surprised your friend doesn't appreciate this as this is pretty basic stuff.

 

I cited the above but he said that you could still make vast improvements and those factors were smaller.
It's true the X308s torsional rigidity isn't that great by modern standards: 13,000 Nm/deg vs the current norm of 20,000 plus.
BMW quote 24,000 Nm/deg for the E39 but Jaguar found it was nearer 15,000. The BMW DOES benefit from laser welding.

 

Well, they're both about 10 tines better than my new XJSC cabriolet.