Front suspension

[happycat]

Tyre size?

Paul

235/60/15

[ptjs1]

Cliff,

That seems to be definitely too low at the front. You need to look up the exact dimensions in your Service Manual. However, I know that the rear unladen height is about 190mm +/- 6mm. And when the front suspension is set up to do wheel alignment by using tie-down tools, we're told to pull the body down to give a front clearance of 153mm.

Even if one assumes that those dimensions are defined as with 225/60 16 tyres (which would only give a height to hub increase over your car of about .65cm) it would seem that your rear is about right and your front seem to be low by at least 5cm, perhaps more. I agree that is slightly contrary if you can still get 3 fingers in horizontally at tyre top. However, 10cm from bottom of front subframe is definitely low.

Assuming all else is correct, it feels like it's time for new front springs and maybe dampers.

Hope that helps

Paul

[happycat]

Cliff,

That seems to be definitely too low at the front. You need to look up the exact dimensions in your Service Manual. However, I know that the rear unladen height is about 190mm +/- 6mm. And when the front suspension is set up to do wheel alignment by using tie-down tools, we're told to pull the body down to give a front clearance of 153mm.

Even if one assumes that those dimensions are defined as with 225/60 16 tyres (which would only give a height to hub increase over your car of about .65cm) it would seem that your rear is about right and your front seem to be low by at least 5cm, perhaps more. I agree that is slightly contrary if you can still get 3 fingers in horizontally at tyre top. However, 10cm from bottom of front subframe is definitely low.

Assuming all else is correct, it feels like it's time for new front springs and maybe dampers.

Hope that helps

Paul

Hi Paul I can get two and half fingers between top of the tyre and wheel arch,and I have small hands! Like I said earlier it's the cross brace that's hitting the ground when the road is uneven,I've found a place that's got springs but there saying they're not suitable for a convertible only coupes!

[ptjs1]

Cliff,

What is the part number that they are quoting for their Coupe springs? And also very important is which make springs are they?

Norman Motors are advertising the correct spec spring kit part number for your convertible (JLM10920) at £70. I don't know what make it is. Martin Robey advertise it as OEM at £78. So, you seem to have choices.

As always it's personal choice but in my view the "Sports" springs are an improvement on the Convertible. They were an option when new anyway. I fitted the Eibach springs on my convertible last year which were developed as a replacement for the Sports springs. I'm also running Bilstein dampers on the front and am happy with that combination.

It would be good to hear what you end up doing.

PAul

[happycat]

Cliff,

What is the part number that they are quoting for their Coupe springs? And also very important is which make springs are they?

Norman Motors are advertising the correct spec spring kit part number for your convertible (JLM10920) at £70. I don't know what make it is. Martin Robey advertise it as OEM at £78. So, you seem to have choices.

As always it's personal choice but in my view the "Sports" springs are an improvement on the Convertible. They were an option when new anyway. I fitted the Eibach springs on my convertible last year which were developed as a replacement for the Sports springs. I'm also running Bilstein dampers on the front and am happy with that combination.

It would be good to hear what you end up doing.

PAul

Thanks for your help I'll look into these places you suggested,out of interest the Eibach springs,are they lower or stiffer than standard springs?

[ptjs1]

Cliff,

As mentioned, the Eibach springs are a development to replace the Sports springs. So, one could assume that they are a bit stiffer. I suspect on a well-setup car and with the use that most of our cars get , you probably wouldn't notice much difference. On the front of my car, the car sits at the correct height.

Good luck

Paul

[davidr]

Paul - I'd be interested to know why you prefer the sports spring. As I've written here on another thread, I find the standard suspension on my Celebration Convertible noticeably harder than my coupe. As we use the Celebration for relaxed cruising I'd like it be a bit more compliant and can only think that sports springs would make the ride even less comfortable.

[ptjs1]

David,

I admit that I do prefer cars to drive more like go-karts! I like predictable steering that turns in with little input (hence running poly for my steering rack bushes), minimal dive on the front end and a rear end that feels like I can turn it just by twisting my body!

Having said that, I don't like banging and crashing over potholes. My XJS is pretty close to how I like it with a tighter feel than original but with some compliance through the bushes and tyres. As a convertible, it will never be super-tight but the X-braces definitely make the car feel tighter than the earlier convertibles that I've driven.

I don't think the Eibach Springs are very hard. Maybe I have a different view to others. Frankly.I have found that the adjustable rear dampers have the most noticeable effect on how the car feels. I played around with the rear Gaz settings for a week or two before I got it to my liking. I don't think the XJS will ever feel like a Lotus Elise, no matter how I set up the suspension! It will always feel a bit heavy up front, and will never steer just by "thinking" it through a corner. So, I still think of it being a little wallowy, but with the current suspension configuration, it can still be hustled around quite quickly yet still with that Jaguar composure.

I wonder if it is the tyre size which is making your earlier car feel more compliant? Also, I do recognise that how much noise a car makes can make us feel that the suspension is harsher. Convertibles will always make more noise, you'll notice the potholes more and maybe that influences your view?

I'd be very happy for you to try my car sometime in case that might help your decision!

Cheers David,

Paul