As the new owner of a lovely X350 in Sport trim with 100k miles on the clock, I am curious.... if/when I need replacement struts, how much would need to be done to replace with Comfort rather than Sport units in future? Are they the same physical size, same connections? Would I need a changer of anti-roll bar? Any other changes required? Would there be an issue with coding/calibrating?
I'd be fascinated to hear from any owner with experience of both Comfort and Sport springs who could describe their perception of the difference between the two. I like the ride as it is, far nicer than my old Mercs - but the softer the better in my opinion. Comfort before "handling".
Jeremy
Swapping Sport for Comfort struts
Re: Swapping Sport for Comfort struts
Physically the same but a change of units may require the ECU to undergo a height check/adjustment.
New, the struts will probably cost you a good 4.5K. Second hand? Well, that would be down to your negotiation skills with a breaker such as Eurojag. You will need to jack the car high to enable air spring removal from the car due their length. Is is ever worth it? Second hand units may also suffer a degree of wear.....
The Arnott kit available through Euro Car Parts uses conventional dampers and coil springs. However with that kit fitted, you will loose the adaptive damping of an air spring standard car.
It might be cheaper and easier to fit smaller wheel rims and higher profile tyres but on R or Super V8 supercharged cars the smallest rim diameter that will still clear brake calipers will be 19".
What tyre pressures are you currently using? About 34psi is about the softest you should be using for normal unladen use.
Look for Pops Jag`s recent post on installing an Arnott kit in the X350 suspension section. It makes interesting reading.
Mike K
New, the struts will probably cost you a good 4.5K. Second hand? Well, that would be down to your negotiation skills with a breaker such as Eurojag. You will need to jack the car high to enable air spring removal from the car due their length. Is is ever worth it? Second hand units may also suffer a degree of wear.....
The Arnott kit available through Euro Car Parts uses conventional dampers and coil springs. However with that kit fitted, you will loose the adaptive damping of an air spring standard car.
It might be cheaper and easier to fit smaller wheel rims and higher profile tyres but on R or Super V8 supercharged cars the smallest rim diameter that will still clear brake calipers will be 19".
What tyre pressures are you currently using? About 34psi is about the softest you should be using for normal unladen use.
Look for Pops Jag`s recent post on installing an Arnott kit in the X350 suspension section. It makes interesting reading.
Mike K
X350 Co-ordinator
2004 XJR
2004 XJR
Re: Swapping Sport for Comfort struts
Thank you for your reply. She's wearing the factory 18" wheels with 50 profile tyres, so hopefully has a good chance of a smooth ride at the 34psi you suggest.
The ECU height check/adjust you mention, presumably that is needed even for replacing with the same, rather than a change in sport/comfort struts, is that correct? What I'm keen to understand is whether it would be as simple as choosing comfort struts instead of sport struts in the event that they need replacing anyway. I would have assumed there is a thicker anti-roll bar on the sport system, but perhaps not? With Bilstein offering new units, they would seem to be the way to go.
The ECU height check/adjust you mention, presumably that is needed even for replacing with the same, rather than a change in sport/comfort struts, is that correct? What I'm keen to understand is whether it would be as simple as choosing comfort struts instead of sport struts in the event that they need replacing anyway. I would have assumed there is a thicker anti-roll bar on the sport system, but perhaps not? With Bilstein offering new units, they would seem to be the way to go.
Re: Swapping Sport for Comfort struts
What size engine does this car have? I suspect you are not running an R or Super V8 supercharged vehicle. Those cars have the big brake Brembo or Teves calipers which need 19" or 20" to accommodate the big four pot calipers. The R has sport air springs and the SV8 has comfort air springs.
I`m not totally up on the Sport spec cars but as far as I can deduce, they would be unlikely to have full blown sport "Red Spot" air springs. A close look at a unit should tell you what you have. A "Green Spot" air spring will have that small circular sticker on it.
It will be unusual for an air damper to give up with mileage less than about 150K miles. You should still have a fair few miles left in the suspension at 100K.
What does cause a rough ride is wear in the lower air spring bushes. Any amount of wear, even in just one air spring will completely confuse the CATS damping system and a mule like ride can result. Check those bushes first before replacing air springs. Replacement bushes are only about £14 via Berkshire Jaguar Components. Buy from their site on eBay and you will save £5 postage!
American X350 models seem to have more air spring issues than we do in the UK. This has been put down to higher climatic conditions which cause the air bags in the air springs to fail more regularly than we experience.
If you really must buy new units, do a good bit of market research before buying. Yes, you can buy from Bilstein direct. Also try the major motor factors such as Euro Car Parts. A good haggle with a local sales manager can often get a good deal.
Hope that helps.
Mike
I`m not totally up on the Sport spec cars but as far as I can deduce, they would be unlikely to have full blown sport "Red Spot" air springs. A close look at a unit should tell you what you have. A "Green Spot" air spring will have that small circular sticker on it.
It will be unusual for an air damper to give up with mileage less than about 150K miles. You should still have a fair few miles left in the suspension at 100K.
What does cause a rough ride is wear in the lower air spring bushes. Any amount of wear, even in just one air spring will completely confuse the CATS damping system and a mule like ride can result. Check those bushes first before replacing air springs. Replacement bushes are only about £14 via Berkshire Jaguar Components. Buy from their site on eBay and you will save £5 postage!
American X350 models seem to have more air spring issues than we do in the UK. This has been put down to higher climatic conditions which cause the air bags in the air springs to fail more regularly than we experience.
If you really must buy new units, do a good bit of market research before buying. Yes, you can buy from Bilstein direct. Also try the major motor factors such as Euro Car Parts. A good haggle with a local sales manager can often get a good deal.
Hope that helps.
Mike
X350 Co-ordinator
2004 XJR
2004 XJR
Re: Swapping Sport for Comfort struts
Super advice, thank you.
It’s a UK model, 3.5 V8. According to the sales brochure of the time it shares the sport dampers with the other “firm” cars, but it uses the same braking system as the SE, so can accommodate more appropriately sized wheels, thank goodness
I’ll certainly pay good attention to the bushes as you’ve suggested - it’s low speed ride that’s jiggly, all settling beautifully at motorway speed.
Thank you,
Jeremy
It’s a UK model, 3.5 V8. According to the sales brochure of the time it shares the sport dampers with the other “firm” cars, but it uses the same braking system as the SE, so can accommodate more appropriately sized wheels, thank goodness
I’ll certainly pay good attention to the bushes as you’ve suggested - it’s low speed ride that’s jiggly, all settling beautifully at motorway speed.
Thank you,
Jeremy
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