Has anyone tried the Konis for the X308? How do they compare vs. the OE XJR Bilsteins?

I can't quite tell what the car should feel like since my dampers are a bit worn. My bet and my research indicates the dampers lean towards under damped vs. critically damped. I think I would like to get it a little more damped than stock. If I can find anyone with a good condition car to take me for a ride, I will be able to tune mine from there.

 

To each his/her own for shock preference, but I went Bilsteins because I have CATS. Is yours CATS "Computer Active Technology Suspension", sport or comfort suspension, this will most likely determine your choice. If your unsure, look under the hood at your shock towers. If you have a single wire lead plugged into the top of your screw post of your shock, you have CATS. If not, you have one of the other 2 and its either your VIN (FordEtis home page) or Code Plate on your driver door that will help you determine that, I don't exactly recall. A parts seller site should ask for your VIN for specificity.

 

That is a good clarification. This vehicle does not have CATS. I am curious how much that system helps though and I'd love to compare it to a good, non-CATS car. Most active dampers barring the magnetorheological dampers don't have a large enough range of adjustment to be very effective. Hopefully, the CATS was better or was more noticeable. I love the concept though.

 

I usually ride with my CATS in Sport mode, so the ride is a bit stiffer and controlled for me. When I want to show off to a passenger, I'll have the car off Sport and pull up to a red light then reach over an press the button....you can feel the car seem to lock in, like a cat getting down ready to leap. Its only slight, but from the passenger view, I just pushed the WTF button.
Your determination now is do you have Comfort or Sport? I'll bet its the Sport being an R model.

 

Not wanting to spoil your dream, but I thought it was long confirmed that the suspension setting is not connected to the sport / comfort button, and is instead a stand-alone unit?

 

You're right Eric. There are no connections between the tranny S Mode and the CATS system.

 

I won't argue with you, but if so, then from what I've read and experienced, the cornering effects are seemingly enhanced as well as slightly longer shift patterns. Or is it that the cornering is enhanced simply because its always there, but because of a longer aggressive shift pattern, it is responding normally, reacting stiffer?
I believe what I need to do, is put it in manual mode more and run it for effect. Its tough to do with all the road construction around here right now though.

 

I like Konis in general but couldn't find them for my 99 XJR (non-cats) so I put Bilsteins back on. Although others state their Bilsteins are still good after 100k miles or even 20 years on the car mine had dry rotted bushings and one was weeping oil so I elected to replace them all rather than just doing the bushings. Compared to the Sachs shocks on my e39 beemer the jag rides a little stiff but it seems ok to me (opinion). I wouldn't want stiffer shocks and several people have mentioned trying KYB's and not being happy with how stiff they turned out to be. One thing that I find regardless of vehicle is if I can hear a noise it affects my perception of what's going on mechanically. With the new shocks and upper bushings, new sway bar bushings, ball joints, and tie rod ends I put on at the same time my cat feels much more planted but that may be mostly due to me not hearing the rattles anymore. Funny what noises can do...

 

I've fitted Koni's to pretty much all the classic restorations but not on these cars. They're adjustable which helps with setup, the Bilsteins aren't, but damped for our cars.

With Cats equipped cars the Piezoelectric dampers have 2 settings normal and stiff, they work independently from the S button and are controlled by 2 sensors, front to back, side to side - working in conjunction with the ABS for traction control and stability control.
if the car is unplugged from them, they're in stiff mode....

Rest of world XJR's had another option, Super Sport Suspension, which mine is fitted with.
Deciphering the paint swatches on the springs can tell what's fitted. The dealer will also have a built sheet with what the car was fitted with originally.

Personally I feel that going with what Jaguar supplied is the way - if you feel the need to stiffen the car up then a euro spec spring/damper setup will give you that, but I'd always advise using OEM parts.

I will say this - Jaguar are pioneers of ride, comfort suppleness of damping and total control of the chassis developed over thousands of hours on proving grounds from Sweden in the snow to deserts - pounding around the test facilities at Gaydon by guys that know what they're doing - while the car is plugged in and collecting data 247. The data is poured over, the developments tweaked, and components tested until we have the finished article that doesn't need altering.
Lowering/cutting springs/aftermarket dampers - all of these things compromise the work in development, and for what, aesthetics? they're not a car to be 'slammed' and almost always compromised in performance, agility and predictability. If you press your car like I do, then you'll already appreciate just how good the chassis engineers where.

 

As a development engineer, I can understand and appreciate the effort better than most. I usually stick with OE or OEM whenever possible for the reasons highlighted. The Super Sport set up sounds like the ticket for springs at a minimum and likely dampers if I don't get Konis. Where can I find the part numbers for the parts in question? Do you know the spring rates and damping specs vs. the standard sports suspension?

I'd like to maintain the character of the car but not have it quite as soft as it feels now although worn dampers are playing a large part of this. I do know if I don't like it, I know it will just get redone. That happened with one of my 540i's. The rear Konis were a quarter turn too stiff and they had to come off and get the rebound softened a tad.

Thanks all!

 

I am going to give a fat ditto to Sean's comments: stick with the OEM for the suspension. That means Bilstein. Your dealer can provide you the data you want from your VIN number.

Koni v Bilsteinsnce I had a 98 Z3; lousy riding qualities from the original rear shocks; replaced with Konis, no improvement, no matter the setting. Dumped the Konis and went to Bilstein: smooth ride, much improved handling. Now that is a hard sprung BMW vice a boulevard ride Jaguar, even an XJR, still . . . .

 

It doesn't help. CATS is too slow to react. I used both Bilstein and Koni. I actually have Koni up from and bilstein in back after disabling my CATS system