hello, looking for an old post i remember viewing about a member who converted from the CATS to non-CATS setup with Bilstein, I cannot find it via the search function, any one have any input on the matter I was toying with the idea of Arden springs and the Bilstein shocks. Mostly i prefer the "S" suspension setting (maybe due to my orig. shocks being worn a bit) on the freeway in normal mode the front is starting to bob up and down on certain dips etc. Just curious to see what others have done and their end result in relation to the orig. components and weather or not they will wear down other components/ tires etc. Any combinations of springs/shocks would be greatly appreciated!!

 

Same discussion going on in the XK forum right now.

https://www.jaguarforums.com/forum/x...ing-xkr-76989/

 

"S" is not a suspension setting. It's a gearbox mode (Sport).

I think it was Brutal who mentioned unplugging the module (Adv Search should get you it if you're careful). You could try that now. Allegedly causes a fault for UK cars, however.

 

Don't do it 93XJRs. I was the member who placed in non CATS struts along with H&R Sport springs. There's isn't an aftermarket performance strut avilable for the "S". With the stock springs, a non CATS Bilstien will be too soft. Go with CATS and H&R Sport springs or Mina Gallery springs (Arden varient). Call Chris of Mina Gallery and tell him Seth from the Jaguar Forum sent you for a set of affordable Mina springs. He'll tell you that the H&R Sport springs actually require a strut with a longer piston throw if traveling on roads with pot holes and dips (this is my case in NY). The Mina springs don't lower the car as far as the H&R's. I'm reverting back to CATS and Mina springs.

 

I too have read in the past that bilsteins from 'V8 Sport' models in combination with lowering springs being a more affordable alternative to CATS-bilstein replacement.

Problem is in the fact that the factory bilsteins, whether they're CATS or Sport variants, are valved at the factory to support stock weight and stock spring rates.

When you introduce lowering springs, which are generally stiffer and reduce bump travel, it can lead to premature damper wear and subsequent failure.

There are motorsports oriented companies out there that specialize in bilstein damper rebuilding and revalving.

Consider sending a set of new 'V8 Sport' bilsteins to have revalved to better suit the lowering springs you intend to run.

If they do not have specific STR experience, which they likely won't, you will probably have to help provide a good deal of additional information regarding suspension specifications and corner weights to assist the company in developing a more accurate valving for you.

I run mina gallery springs on my high mileage original CATS dampers and they still seem okay.
Would be nice if one could override the CATS computer and dial in some more aggressive valving to suit the lowering springs, but its possible the CATS computer might be adaptive enough and taking feedback from some sensor(s) I'm not aware of, and have already dialed in some additional stiffness into the CATS dampers to compensate for the lowering springs. I'm not super familiar with the operational theory of the CATS suspension, and if the electronic adjusters at the top of the dampers also provide some sort of feedback as well... or a gyroscope perhaps inside the CATS module... speculation at best here folks.

 

Thanks all. I appreciate the warnings and will likely suck it up and buy new CATS shocks at least for the front, the rear seem firmly planted and well controlled. Will give the Mina folks a call to see what they say, overall are their spring considerably stiffer than the stock units ? If it is too harsh may just keep her as is for now. Thanks again!!

 

CATS dampers are significantly more expensive than the V8 Sport bilsteins.

I wonder if a bilstein rebuilder could tackle an overhaul on our factory CATS dampers. There is little difference between a CATS adjustable bilstein and a standard adjustable bilstein dampers beyond an electronic solenoid that controls the adjustment rod inside the damper piston.

edit: Mina's seem to ride plenty soft for me. Then again, I'm young and partial to more aggressive setups, others may not like them. Contact mina, see how much stiffer the springs really are, I doubt they're more than 10-15% stiffer over stock though.

 

I tried to get non-CATS V8 sport Bilsteins for my STR, and the rears have been on national back order for over 2 months now (so I've been told by several retailers locally and online); so unless you find a place with leftovers in stock your chances of getting them any time soon are probably very low. If I think the ride is too soft after I finally get them (3 weeks or so was the estimate from Bilstein), I'll convert back to the full stiff CATS, but I only drive the car a few times a month right now.

The reason I am planning on going to the Bilsteins is because after my H&R spring install I could not get the CATS system fault message off and the car rides a little stiff for my liking. I went to the dealer and they told me they couldn't reset it and the only way to fix it was to return it to stock and then possibly replace the struts. I've since disconnected the control module to get rid of the message, but the suspension remains in full stiff.

 

poking around the bilstein website they show a shock for f/r with CATS electronic sports suspension, cant see any electronic plug from the picture though found a few places in the UK that advertises them being available

Parts catalogue

I suppose that they are comparable in valving but lack the electronics etc.

 

Gentlemen, the stock CATS are Bilstiens and provide more dampening than the Bilstiens for the S-Type V-8 Sport suspension, which by the way, are presently in my 03 STR. The Mina springs provide a slightly higher ride hieght and a softer ride than the H&R Sport springs. Go with the CATS with Mina springs for the best of both worlds.QuartzSTR, after the H&R Sport spring install, a hard re-set of the ECU should have cancelled the CATS system fault. Unplugging the module on a CATS strut suspension defaults it to the "dead firm" position.

 

Mina are higher in ride height ?

 

If you can, please post a summary of the UK ones. Someone will need them sooner or later.

 

Certainly:

Bil_006994

BILSTEIN - B4 ACD (Ersatzteil)
Gas Pressure, For vehicles with sports suspension, For vehicles with electronic suspension control, For vehicles with CATS;

Part numbers:
Front: 20-070854
Rear: 20-070885

doing a quick cross reference on the Jaguar part number Bilstein lists they do not seem to apply to the super charged models

 

Exactly, the STR CATS are provided with firmer valving and slightly deeper throw. Call Chris of Mina Galleries. He'll provide the lowest price for both springs and CATS struts. Tell him Seth sent you.

 

I believe he meant Mina's ride higher (less drop) than the H&R lowering springs for the STR. Mina's provide a noticeable drop over stock.

 

Yes. The Mina springs lower the car up to approx. 1", whilst the H&R's lower up to 1 1/4". The Mina's are also less firm than the H&R's.

 

I performed a hard reset and the fault message re-appeared immediately. I had the dealer diagnose it to no avail. It has been in full stiff ever since the install and I really don't know what else to do but replace the struts. Nothing was damaged during the install, and all the connectors are fine and the pins in the top of the strut are all straight.

 

Hmmm... perhaps one of the front or rear CATS struts, not all, malfunctioned? If the CATS performed well before the H&R Sport spring install, one ould suspect a wire/harness fault.

 

I've been over the suspension many times, and after the dealer couldn't/wouldn't tell me exactly what the problem was and their solution was to replace everything I have decided not to pursue it any further and go with the Bilsteins. The struts and electrical connectors do not appear damaged in any way, and the connectors appear fine as well. Whatever the problem is, it is immediately setting a hard code after an ecu reset. Since I can get all 4 Bilsteins for $400 vs. ~$400/each for the CATS struts and not knowing if that will fix the problem, the solution is easy for me. Although if you or anyone else has any more ideas about how to go about diagnosing it, I am still open to that while the CATS struts are still on the car.

 

How about disconnecting each in turn and measuring the resistance (& impedance if you can). Then reconnect and unplug at the module end, and repeat the readings. Seems likely one will be different.

And of course: what codes are in the module?