Bilstein PSS10 Install w/Linear Springs, Vorshlag Camber Plates and Rouge RSMs
First let me say I love Bilstein PSS9/10 suspensions.
I've had them on my E36M3 and E46M3.
The damping range for the street is good, but for the track they're even better.
I always prefer to convert them to linear springs, wish they would come with these stock.
I usually like to run 525f/550r for a more street setup, and 525f/650r for more track oriented.
So I ordered a set for the Z4M pretty much the day after I bought the car.
I also ordered Vorshlag camber plates (the best) and some Rogue rear shock mounts (RSM) also a
must for the hard to access Z4M rear shock mounts.
Here is the kit.
The bright blue progressive rate springs come with the PSS10 kit, I will be swapping these out for some Eibach ERS and Hypercoil springs I have.
Picture showing the Vorshlag camber plates installed.
This is also my 3rd set of Vorshlag camber plates, IMHO they are the best.
They have the lowest stack height (meaning they are the slimmest plates you can get), and the spherical bearing is both strong and very quiet.
The only downside is as a result of the low stack height, the nut sticks up high and can interfere with the strut tower flange.
Front Suspension Install
Getting started on the fronts
Pretty straightforward removing the OEM front struts.
I use vice grips to keep the back of the end link from spinning when removing the nut.
After that there's 2 bolts that hold the bottom of the strut and then 1 bolt a few inches above those that runs front to back.
Then remove the 3 top nuts from under the hood.
Old one out
Fronts set to level 1 of 10. Softest setting for now.
New Bilstein PSS10 assembly going in
Here's the three lower mounting points, top bolt running front to back, and the two bolts (not yet installed) at the bottom where the strut flange meets the knuckle.
The top of the strut tower has a flange that limits the movement of the top nut when the maximum caster setting is used.
This means I'll have limited camber unless I move the caster to medium setting, or modify my strut mounts to gain clearance.
So I clearanced the sheet metal a bit.
And the fronts are installed.
Rear Suspension Install
Now to the rears, this is slightly more difficult.
You've got to remove the battery cover, and access the rear upper shock mounts.
Three nuts on top hold the battery cover down. Remove these.
Next remove the plate/bracket that has the twist knob that moves the plastic shelf up and down.
Then you can pull back the carpet, and the foam padding.
Finally you can install the Rogue upper shock mounts and save yourself the hassle of ever having to remove this stuff again.
This is because the Rogue rear shock mounts have two parts.
The part on the right mounts from inside the car and the studs point downward into the wheel well.
The part on the left mounts to the shock.
Here is the part mounted on the shock.
Here's the view with the OEM shock removed, and before installing the Rouge rear shock mount plate from inside the car.
After installing you'll only need access from here.
Here it is installed.
So if you ever have to remove the rear shocks, you only need to loosen the nuts from here (in the wheel well) and remove them.
You no longer have to access these mounts from inside the car.
These Rogue plates are a must have, and for only $110 they are worth it.
Here's how easy they install now.
Rear shocks installed and set to level 1 of 10. Softest setting for now.
Here's the PSS10 spring and adjustable spring perch installed.
I planned on using the springs from the black car, which was going to use the springs from the race car.
But I didn't have time to swap 3 sets of springs so I temporarily installed the progressive springs that came with the PSS10s in the rear for now.
After adjusting the ride heights, here is the height I settled on.
This is about 3/4" lower than OEM I believe.
And to finish it off right, I went to GT Peace to do a nice alignment.
I am setting this car up somewhere between spirited street driving and track day. So I went for these settings:
Front
Camber: -2.8 deg
Caster: 7.5 deg
Toe: 0.10 total toe in
Rear
Camber: -1.8 deg
Toe: 0.10 total toe in
Impressions on the Bilstein PSS10 suspension
I have to say I was not at all dissapointed in this PSS10 kit for my Z4M roadster. In fact, so far I think it is the best of the Bilstein PSSX kits I've had. The ride quality has improved over OEM, with the only exception possibly being abrupt changes in road surface (like expansion joints on bridges, or pot holes). But otherwise the car is much less floaty and wallowy. The shocks feel smoother and body motions are much more controlled. There is less body roll of course, and the car feels more composed. There is much less lag time from making an input to the car responding. There is much more confidence in pushing the car harder into turns and at high speeds.
Of course the Vorshlag camber allowed me to maximize my alignment settings, which in turn maximize grip. The linear rate front springs also help to give a more consistent amount of body roll, and fortunately I haven't yet noticed any drawbacks to the PSS10 rear springs.
I have to say that I am completely happy with my Bilstein PSS10 suspension. I think it is the best suspension available for the money. The valving is great for the track and can handle high spring rates, yet it still feels good on the street. Bilstein dampers can last 100k miles or more which can't be said by any other dampers I'm aware of. And the adjustability range I expect will be very good.
One criticism of the PSS9s on my E36M3 is that the amount of damping force adjustment from 1-2 is the same as from 2-10. I know this from dynoing them. Also, 1 is the stiffest setting on the PSS9s and 10 is the stiffest setting on the PSS10s. Weird. Oh well, at least knowing this kind of makes the problem less significant. Point is I think the PSS10s may have resolved the shortcomings with the PSS9s. And short of getting Ohlins or MCS, I think the PSS10s is likely the best kit out there. I'll confirm or deny this statement once I get a chance to track this car.