I need some advise. My back is rather bad and the XJR suspension doesn't do me many favours, so I am thinking about softening the ride.

Bought the car last summer. The dealer had an XJ8 3,2 1998 and a XJR6 from 1995. Tested both with my family and even though we all preferred the ride of the XJ8, the grunt of the XJR6 made me buy that instead. I know the XJ8 have more advanced suspension with CATS aso, but can I get close to that comfort in my XJR6, without ruining it?

There are clunks from the rear end whenever going over a pot hole or speed bump, so I am rather sure the rear shocks will have to be replaced. This makes this the perfect moment to consider a softer ride, but how?

The ride may be better just by installing new shocks, but if that doesn't do it, another replacement will be a financial nightmare, as my back doesn't allow me to do this myself.

So what are my options? Softer springs front and rear? Softer shocks? Downgrading to non-XJR parts?

 

I have to agree. I was shocked at the harsh ride of my XJR. Previously owning a XJ40, I was expecting a soothing Jaguar ride. It really does not handle that well too.

Sure, its a large heavy car. But the handling is not in the same class as a sports car. So rough with dissapointing handling. I understand that it isn't going to handle like my Callaway Scirocco, which is just an over grown go-kart.

If I had to choose again, I'd buy the XJ12 for the horsepower with the smooth ride.

Changing the springs and the shocks might soften things up, but Jesus.

 

The XJR used different springs, shocks, anti-roll bars, and tires.

I'd say the springs are the biggest contributor to the somewhat firm ride...followed by the other items in the order listed.

However, using standard XJ6 shocks and switching to taller profile tires may yield the improvement you're looking for.

Cheers
DD

 

First thing. if you want to change the ride; you have to change all of your four suspensions. second thing to change the ride, u have to replace whole suspension assembly which cost more. and though it is not sure that ride will be more comfort at the level you want because the wheels and tires also had some effects on the ride. so i'm personally advice prefer expert for doing this rather than your self. and more better if you don't do this.

 

Replace the whole suspension "assembly"?

Why ?


Cheers
DD

 

Also consider Kumho Ecsta LX Platinum tires (KU27). Those are supposed to have very good ride comfort.

 

Agree with Doug as usual. Springs, smaller wheels with taller tyres are a very easy way, but you don't say what rubbers are on your XJR.

Also have a look at Polybush UK. They make different rated bushes depending on what you require.

Also a shock absorbing cushion on your seat might help, and is cheap. (I also have a back problem after an accident 4 discs gone, and sometimes need a little help).

 

Thanks for the input. I really appreciate it.

The current rims are the original 17" XJR and the tires are 'Winter 210 Performance' 255/45 from Pirelli. I believe they are rather old and they are definately on their last season. I have planned on using Falken FK-452 or maybe Kumho Ecsta SPT KU31 for summer tires.

Will the car be higher, if I install XJ6 springs? I think the stance is spot on as it is. The XJR doesn't need lowering, but definately not 'highering' either

 

I also have a 1995 X300, however not the R model.
I recently had the whole rear end rebushed, and new standard shocks.
The ride quality was transformed. I had been getting the clunks from the rear, and thumps over bumps and judder bars.
Now I hardly need to slow down for speed bumps.
Consider that maybe your bushes and shocks are maybe worn out.
If so, new ones will mke a huge difference.

 

From the spec page in the service manual we see that's there's very little difference in overall height.......


6 cylinder comfort suspension 51.7
12 cylinder comfort suspension 51.8
6 cylinder sport suspension 51.5
12 cylinder sport suspension 51.5
6 cylinder supercharged 51.3

....so I wouldn't expect much change in the stance of the car with standard XJ6 springs

Cheers
DD

 

@Doug
So the car could get 4mm higher. Perhaps a bit more, due to weight differences? I suppose the extra weight of the XJR engine isn't enough to cause balance front-rear issues... All in all, the XJ6 springs seems be an option. If they actually fit, that is.

@jagqueen
Good point. I have been thinking about that too. The bushings were checked and a few replaced when I got the car in september, so they should be ok. But I wonder how much the ride would change, just by replacing the bad rear shocks?

 

No, about 10mm higher.....the figures mentioned above are in inches!

Still, 10mm isn't much.

The 245/55x17 tires on an XJR are a bit shorter than the 225/60x16 used on the standard XJ6. That might be the difference.

Cheers
DD

 

I was into the passenger seat in X300 XJR . The owner said that was belonged to his wife and to make it more comfortable he dropped 16" wheels . The car was kinda smooter compared to stock XJRs too

 

Just 'kinda'? Doesn't sound like it's worth the effort?

 

Broadly speaking a taller profile tire will give a softer ride but there are tire-to-tire differences. If you have 45-series tires with somewhat less-stiff-than-typical sidewalls and replace them with 60-series tires with somewhat stiffer-than-most sidewalls, the difference might be minor

As an aside, going to 225/60x16 wheels/tires (versus 255/45x17) gives you a much larger tire selection to choose from...including some that'll actually give a respectable tread life. Most the 17" sizes have very low tread life ratings.

Cheers
DD

 

A quick update... The rear shocks have been replaced with standard XJ6 shocks and the tires with Falken FK-452 255/45-17". The old tires was in so bad condition, that the rubber peeled off of the sides, leaving me no choice but a high tire preassure of 3 bar. The manual suggests 1.9 bar for comfort and 2.3 as standard, so I am on 2.2 right now, considering going lower. Any thoughts on that?

I dropped the idea of changing springs and tires to something very different, as it would be rather expensive, ruin the XJR concept and make the car impossible to sell later on.

All in all it's a better ride now. Wheel alignment, fixing a high idle and getting rid of the noise when going over bumpbs and potholes certainly helped too, even though they may not make the ride softer. It's just the overall driving experience that's been improved. It's still not as soft as my friends BMW E39 540i for example, but I never expected it to be. Right now I am quite happy with the car and plan on keeping it for a while.

Thanks to all who replied here, making me give the XJR a chance.

 

Good point, good observation about overall driving experience.

Clanks/rattles etc over bumps are obviously annoying and certainly magnify the feeling of "roughness" or "poor ride quality".

You're obviously aware of the distinction between real and percevied "rough ride" but it's an interesting and seldom-discussed aspect.

Cheers
DD