after much deliberation and debates in the forum, "air suspension vs conversion." i decided to go with the conversion. not only because of the cost factor but the reliability that was offered, maintenance, unscheduled repairs, predictability etc. i put myself in a situation: how safe would i feel on a lengthy road trip? being that this wasn't my first time dealing with the air suspension, and a great portion of this forum is about air suspension problems, plus being quoted nearly 7 grand for my air suspension repairs and a little under 3 grand for the conversion. it was a no brainer. my 2 front air shocks and compressor needed to be replaced, also 1 of my rear shocks had a slow leak along with some bad air lines.
it took two days for the conversion to be complete. after so i went for a drive to see how i felt about my choice. after a twisty fast paced drive i couldn't be happier, i know i made the right decision. it truly feels just a good as my air suspension. i was incredibly impressed! i expected to be underwhelmed from threads I've read on the arnot conversion. but this conversion is a bilstein kit. the car has correct stance it doesn't look too high nor too low. it comes with the software for the headlights to adjust accordingly. the ride soft when it needs to be and nice and tight in the bends. i haven't seen anyone else who does the bilstein conversion other than motors cars ltd. if i heard correctly they did say that this was "their" kit and software. i believe motorcars ltd is only texas wide. 2 shops here in houston 1 in dallas and 1 in austin. if anyone is interested here is their site along with a link to the conversion kits page. again i am very impressed and happy with my choice.

XJ8 Spring Conversion Kit - asc.kit.xj8

Jaguar Parts, Land Rover Parts. Used Jaguar Parts, Used Land Rover Parts.

 

I remain highly skeptical of Arnott's kit. I think they're good at the aftermarket air suspension components they produce, but my assessment of their kit is that it's not been fully sorted, and they are using early adopters as beta testers. No thanks (see another thread where I have been vilified for daring to take a position of skepticism/cynicism)

I have spoken to Motor Cars LTD. here in Dallas about their kit. I am carefully considering it, so I'm grateful for the feedback. I'll need to do something before the weather cools down.

Was the $3K cost you are reporting inclusive of labor? If so, that's a pretty square deal. Josh, please keep us posted on any longer-term reflections on the ride and handling characteristics, and any problems that may crop up (I sincerely hope there are none) Good on you!

 

supertrav the actual total was $2,761 thats labor, the kit, and alignment. i actually already read that thread where you tore arnot apart lol. after a few threads that had arnot's conversion i read the kit was way too soft or too stiff. if motor cars was using arnots kit i would have just had my air suspension overhauled and cried while writing a check for 7 grand. but motorcars assured me the bilstein kit far surpasses arnots in quality and software. the tech actually said arnot's kit is a joke. also they let me drive their shops xjr with the conversion before deciding. that helped a lot. i hope my suspension problems are over as well but if they aren't there is a one year warrantee on labor and two years on the kit.

 

I believe Bilstein made the shocks part of the original air spring unit. So my question is - does your conversion retain the variable shocks on the original unit ? The Jaguar X350 CATS system varies the shock rate depending on how the car is being driven.

 

fraser its a whole new shock assembly, they don't actually convert the existing air shocks on the jaguar conversion, but they do on land rover conversion. they take the existing air shock and rebuild it into a hydraulic one.

 

Yes, sure, it's a new shock/spring assembly, but have Bilstein provided the variable shock facility like they did on the air spring units ? The shocks work independently of the air springs even though they are a single unit; the shock has no influence on the air spring and vice versa.

 

oh, sorry fraser i miss understood you the 1st time. basically how it all was explained to me, the system is made to mimic the air system as much as possible with traditional springs and struts. it also has its own software to aid it, and have your HID lights operate accordingly.

 

So it uses a hydraulic pump, kind of like what Infiniti did back in the '90s for the Q?

 

no jahummer, not the jag conversion. the jags is your gas filled shock. the hydraulic kit i was referring to was the one they make for land rover. they take the air shock and convert it to a hydraulic shock. i really don't know much more than that. i was just schooled by the tech. on the difference of the conversion jobs they do.
i miss understood what fraser was asking the 1st time.

 

So if they are traditional gas struts, what kind of leveling equipment are they using? I ask because it either has to be pneumatic or hydraulic to be able change the ride leveling, after all this software you mention has to control something.

By the way thank you very much for the report, sharing you experience is very valuable info for someone considering the conversion. And glad you are pleased with the results.

 

@ jahummer i don't believe the software is to change the ride leveling, the car stays at one stance. with coil springs and gas pressured shocks i really wouldn't know how it would be possible to change ride leveling with the force behind the two. the software is to keep your hid's to adjust properly with road changes. it also bypasses the air suspension software to prevent any suspension fault messages from appearing or triggering other sensors that work with the air ride. for example: when my air ride went out my gas gauge went crazy every time i would start the car, now its back to normal and hasn't acted up.

yes i am very happy with the conversion, of course no gas pressured coil system will be better than an air ride or hydraulic suspension when it comes to changing road conditions. shocks and coils are really "one trick ponies" what you see is what you get. the build quality and design is really the only way to even compete with the other two. in my opinion its seems the quality is their with this bilstein kit.

 

I suspected as much. The HID lights on our cars, unless a MY '03 & some '04, do not have the "guts" to level the headlights. Jaguar found it redundant with the air suspension capable of doing essentially the same thing. But not to worry, it is not really that critical in the US for self-leveling low beams.

What the software is for and essential to, as you noted, prevent feedback error codes due to missing components.

 

@ jahummer exactly right. the main objective is prevention of error codes. as far as the the software working with the leveling HID's i just look at that as a bonus. they are wonderful when working properly, but if they didn't adjust anymore i could deal with it.

 

The takeaway for me is that we have Josh, a Super V8 owner, who is reporting very little or no discernible differences in ride or handling in his own car, and he was impressed with the ride and handling of another car, an XJR, 2 cars, with the Motor Cars Ltd. kit installed.

This is opposed to buyers of the Arnott kit, which by almost all accounts produces easily discernible differences in ride and handling that buyers become apologists for, and seem to be trying to convince themselves and others that significant differences in ride and handling is acceptable. I am excited about the Motor Cars Ltd. kit based on Josh's experience, and am looking to join him by having the install done on my XJR. Thanks again, Josh.

 

motorcars ltd. actually has a youtube account with a 3 part video not the conversion. here you can see what the kit looks like. it looks sophisticated for it being a coil/shock setup. i have never seen a setup like it before. heres the link to the vid:


maybe many of you already knew this, but i recently found out that after many complaints to arnot for their conversion a recall/redesign was made. guess who they used? bilstein. I'm not exactly sure what all bilstein has done but from what i read its seems its shocks and springs are bilstein. (which are the most important parts) found this find interesting. thought i'd share.

 

Is the Arnott Kit and MotorCars Kit being manufactured by Bilstein or independently with Bilstein struts/springs? What is different about this kit from the Arnott Kit?

Spring height? Shock valving?

 

@ 04xj8 the motor cars kit is from black dog manufacturing. they put together a bilstein kit using 100% bilstein products, solely for motorcars ltd. arnots "new and revised" conversion uses bilstein shocks and springs but is labeled under arnots kit. looking at the two kits they very much look alike. after a recall was made on the arnot kit they teamed with bilstein for help which i believe is why they look so much alike.

as far as spring height and shock valving they virtually have to be the same if they have the same coil and springs.

hope this answered your question

 

IMHO two things need answering here about these steel spring conversions: -

1. If you put some heavy things in the trunk, (or carry passengers in the rear), how do the headlamps get adjusted to the lowering of the rear of the car ? With the air suspension, the car is always kept at the correct ride height by adjusting the air pressure in the spring units. However as this process is automatic, there is no driver facility provided to raise or lower the headlamps.

2. How is the CATS supported ? This relies on switcheable shocks, (Hard-Soft) using a signal from the suspension control. Are the shocks that come with the steel springs also switcheable ?

 

1. No

2. No.

 

Yes, Thanks!

If the kits are essentially the same now... Why pay $300 more for the MotorCar Kit?