My current shocks where already used for almost 110Kmiles, so I decided to refurbish my original set (that came with the car) and make them again stiffer then this set which was already about 10 to 15% stiffer, am honestly not sure anymore, as I have bought them as they where.

I have sent my original dampers (which had 130Kmiles on them) to the shop to have them refurbished and make then about 20% stiffer. The fronts turned out even more stiffer, as the compression stroke was only about 40kg, and that is set now to 50kg. The rears went from 125kg to 150kg. See attachment for more details, irrc the speeds was 0.13 m/s for the measurement.

The 1st test drive is very promising; I really love it so far, but will give my final review in about a week or so, after some good miles.

The price is about 200 euros per shock, and the good news is they will be as new again, and better due to them being stiffer, and you keep the CATS function as it was.

 

Very interesting, and certainly less expensive than a new CATS shock.

Is there much change to the feel when they are in "soft" mode?

 

Attached is the curve for the soft setting at the fronts, I can't find the dyno curve for the rear now.

Also attached is a picture of the original rear shocks, that yellow bushing was about to fail soon and is what’s causing the rattle that some have experienced (I had it 3 times already).

 

That's interesting, I would have expected that the soft setting would have reduced the compression and rebound by similar percentages, but it seems to have a much larger affect on rebound side.

I guess that would explain why fixing the CATS shock in "firm" modes has a sort of bouncy feel. The compression is about the same but on the rebound the car stops moving faster than the occupants giving that sort of "over a hill" feeling.

Did you get to see what the CATS mechanism looks like?

The solenoid must be more complicated than a simple bypass or it would have reduced the compression as well. Does the soft mode have a separate shim stack?

 

Iirc correct for the rear there was also an effect on the compression stroke, but am not sure as I can;t find the graph.

There wasn't a way to do either seperately (so soft/hard setting), you could only shimm the hard setting.

 

After about 600 miles I can say so far that I love it. The car feels very nice and firm, a big difference, yet the comfort has only slightly gone back, way compensated by the great feel.

There is also less nose jump and diving at hard acceleration or braking, so for now I can certainly say this upgrade in stiffness was worth it for me, and recommendable for the performance minded under us.

Any good refurbishment place should be able to do this, but if not, I can point you to the guy that did mine in the Netherlands (he also worked as an engineer at Bilstein, which helped).

 

What springssprings are you running with these new dampers ?

 

I am using the Eibach ones, but I am not sure these are still available.

 

Is this saying it's possible to put CATS dampers into different settings & if so how?

 

^^^ The CATS computer does that on the fly through the solenoid at the top of the damper piston...

 

There was a thread about someone tricking the system electronically to give a manual control to the soft/firm adjustment. You might be able to find it with a search.

 

What Avos has done is to change the internal valving of the shock to change the response. They still have soft/firm but his are now firmer than stock in both settings.

If you want manual control of firm / soft by way of a switch, that can be done too. For fun I connected it to the sport switch for the transmission, so sport now also locks the shocks to firm mode.

It's kind of fun for the twisties, but on the highway the rebound being damped so much makes the car less comfortable to cruise in.

If you want to experiment you can just unplug the controller in the boot and you will get to feel what it is like permanently in firm mode.

 

That sounds sensible, I'm surprised it wasn't a factory option.

 

Connecting the CATS to the sport switch? Should have been that way stock (Auto/Manual Firm). An obvious choice.

Oh well, ... I guess it's off to review the car's schematics (again!).

It's "what we do" - lol

 

It took a few tried but in post #33 there is a circuit that works.

This is the thread:
https://www.jaguarforums.com/forum/x...e2/#post622494

 

Thanks CC. Quite slick. Could we also just wire-up a six pin relay so that the red-white wire is switched-off with selection of sport mode? I'm an Aero kinda guy, so EE is still PFM to me.

Considering that your switch is solid state (and in the trunk), what causes the audible click you mentioned?