I have tried to find out if there is any difference between XJR springs and standard XJ springs ?
Have asked around but nobody really knows if the XJR are lower, firmer or if there is any difference, so do any one here know some fact about that question.

It looks like the XJR's are just a little lower and they have to be firmer i guess with all that power.

 

There are a few subtle variations on the XJR springs but I'm sure it's fair to say that they're all firmer than standard XJ6 springs.

XJR ride height is a bit lower as well...presumably due to the springs. USA market XJRs are a bit higher riding than other market XJRs but lower than the standard XJ6, according to the manuals.

Cheers
DD

 

Thanks Doug

I thought so, but wasn't sure.

 

This may help.

I attached some data about the rear XJR springs that I obtained from Jaguar. The front ones may have different spring constants etc.

If you have comparable data for the naturally aspirated XJ's, it might help you confirm/dismiss your hypothesis.

BTW Jaguar's heritage division will be glad to send you any data you request about these cars--that's how I got this!

(At high speeds I could feel a vibration in the steering wheel and I felt that the ride quality was not what anyone would expect from a Jaguar. I took it to several mechanics, even to ones that said they were familiar with Jaguars. They threw several opinions at me...and several, expensive, repair quotes. I decided to just rip out the entire front suspension out. Turns out the front two springs were broken and almost rust welded to their mountings. After several weeks of frustrating searches trying to find new springs and comparing spring constants, ride heights etc of aftermarket springs--since Jaguar didn't offer any for sale--I gave up and went to a scrap yard and asked the yardmen to pull me the front springs off a '95 XJR. After some sanding and painting, everything looks/works fine.)

Good luck replacing* your springs though

Anyway, hope some of that gibberish was of some use.

*I didn't have the special tool (JD115) nor did I bother fabricating one (search up 'Don B' in the forum threads for details); I used a 12 to hydraulic press to compress the springs and used some high strength rope to hold the compressed spring in place. Buttoned everything up. Cut rope. Done.

Dangerous? Perhaps. Effective? Very.*

 

Thanks Someguywithajag

So we think its only the front spring from a XJR that is lower then the Standart spring or do i reed this wrong ?

but i guess stiffer in bough ends on a XJR ?

 

Welcome.

I believe all 4 springs are lower/stiffer for the XJR vs the standard XJ.

 

I have an XJR6 and recenty rebuilt the front suspension. The XJR spring are also stiffer at the front to carry the extra weight of the induction parts and the GM 4l80e transmission. I had a broken front spring and tried replacing the fronts with some off a 3.2 sport which I had in my garage. The car sank almost to the bumpstops, see my previous posts. I ended up getting some copies made of the good original spring. I also found that the original XJR dampers contribute significantly to ride height believe it or not. A lot of work and messing about.
If you have a NA xj6 and you want sportier feel without trouble, I would suggest springs dampers and roll/sway bars from a sport model as the car weights will be the same.
I used to have a 3.2 sport and it drove really well. 225 x 16" tyres work better than my xjr 255 x 17" in my opinion.

John

 

You've got me wondering, are there different front springs or shocks for the XJR6 with manual vs. automatic transmission? My 1995 XJR6 has, as far as I know, stock springs matched with the correct (i.e. not shared with the XJ12) Bilstein Touring shocks, but it has a slightly if noticeably higher front ride height vs. the rear and an unusual harshness over bumps. As with all XJR6s in the US it came from the factory as an automatic but received the Getrag 290 manual swap at some point in its life. This is assuming that there is a significant weight difference between the manual and automatic transmissions, which much of the time there is, but I can't assume so in this case.