There is a company in the uk offering -20/25mm lower than the EU XJR.
That is, besides a Japanese company, and maybe Arden, about the only one which should work for you.
All others promise a lot but deliver nothing lower than the EU XJR.

 

i don't want lower, just identical to euro

 

I have those springs Eric is talking about. they are superb to original in every way, I would recommend!. powerhouse.co.uk

 

Hi,

The ride height is set up by spring packers of different thicknesses. 1.5 mm (ROW) or 4.5 mm (NAS) for the front springs and 3.4 mm (ROW) or 6.55 mm (NAS) in the rear.

So if you replace your packers with ROW-spec you're good to go :-)

See here:
https://www.jaguarclassicparts.com/u...d-damper-front


​​​​https://www.jaguarclassicparts.com/u...-fittings-rear

 

Now that would be awesome to see some pictures of your car with them fitted.
Powerhouse seems to have good reviews over all, and they are certainly friendly and helpful.

The only problem I still have is that they (like all others) only advertise the drop, but that says nothing if you don't know where to start from.
They at least confirmed it should be based on a UK XJR, but I am still missing solid numbers.

 

I also wondered for years if the thickness in the packers was how Jaguar handled the ride height differences.
I particular wondered, cause mathematically it does not add up on our suspension lay-out, the ~3mm difference is too little for it.

I now believe the difference in packers is only to compensate for the difference in equipment every car came with, and to obtain the same ride height.
Our MB SLK can have 5 (!) different packer thicknesses front and rear.
There is an official Mercedes Benz Workshop instruction which one to fit, depending transmission type, airco fitted, larger battery, sound system, etc.
I presume Jaguar followed the same principle.

 

You're sure? Taken into account the leverage effect of the control arms + that the top perch of the springs is bent inwards (at least of the front springs) and (most probably) different spring dimensions it's almost perfectly plausible to me that it works that way (at least for the XJR). I re-specced my ROW XJR with the correct packers (1.5 and 3.4 mm) as they got lost with the pre-owners and the ride height is now bang on with the factory spec. The change was particularly evident in the rear, as the car was sagging a bit (in side view).

Since the XJR springs are different to all the other springs (even the XJ8 sports suspension springs) this packer-thickness thing might apply to XJR-only. Meaning that the ride height of all other XJ8 models is controlled by different spring dimensions/lengths.

 

...rethinking the whole spring-thing I remember all four springs tracing the shape of an arc with the car sitting on its wheels. Due to this the thickness of the packers should have an even larger impact on the leverage effect as the mount points of the springs are quite close to the fulcrum of each control arm. Does this makes sense in anybody else's head too? ;-)
It's kinda difficult to express this kind of complex issue in my third language *gg*

 

You are expressing the exact same thoughts I had for years, there must be some other threads on the same issue.
Might be something like great minds think alike or so ...

It also makes perfect sense from a manufacturing point of view, same springs for different models ... cheaper.

I lost my notes and sketches, but if you try to work it out with all the dimensions, plus sinus, cosinus and tangens involved, it did not work out.
The 3mm packer difference does not translate into a ~20mm ride height difference.
Maybe I did something wrong though ... never liked my math teacher

 

I see, you already immersed into the subject matter :-)

Unfortunately I'm afraid that the calculations won't stop there. Due to the arc shaped type of installation the packers will have their strongest effect = force on the inner side of the spring. This will lead to a different deflection behaviour than just compressing a spring alongside one single axis. Plus taken into account that most of suspension springs do show progressive instead of linear spring characteristics any calculation will stop there as a lot of (to us) unknown parameters will enter the playground (bending moment, spring characteristics curve etc).

@jonathanlewis: if you remove the wheels (or put your car on a lift) you should be able to determine what kind of packers your car comes with (see pic between spring and rusty spring pan). Pic is from a ROW-spec Daimler Super V8 = VDP supercharged with comfort CATS suspension.
If you know how to turn the wrenches on your car and have the right tools you might try to remove the rear packers for trial and see what effect this has on the ride height. The rears are a bit easier to remove than the fronts so this is the right way to go if you go down the trial-and-error-route ;-)

 

I cant find any pics right now and car is parked for winter away from home. I'll make some pics when I'am at the car... within a month i hope.

 

Maybe, just maybe, you can make the measurements from center cap to wheel arch on your car next month?
I should really appreciate that if you can, it will give me the confirmation I am long looking for.

 

34cm both front and rear- wheel center to arch

 

You are my hero for today, thank you very much.
I just checked my notes, I run ~36 front and rear (depending fuel), so that is indeed an other 2 cm difference ..... mmmmmmmmm
Out of funds right now, all in the XK, but you got me thinking again ....

 

For reference my US spec XJR comes out at 406.4mm front (top of arch to....)
394.97mm rear - arch top to growler bottom - so minus the growler radius to match others

 

I'm really liking the 20" rear 19" front - it gives the car another level of stance, a bit of rake angle. I'll add my UK spec measurements over the weekend.