Bilstein B16 PSS10 Z4M Info

[pcube]

Hey all,

I know there are several threads discussing this particular set of coilovers, but there are bits of information all over the place which requires some searching so thought I would share what I did. Hopefully it benefits someone in the future.

Some background. My car is entirely street driven (unlikely it will ever see the track), and my previous set of coils were H&R. They have been on the car for 6+ years and about 60k miles. I remember that they were quite comfy when they were first installed, but recently it seemed like there was zero damping which prompted my decision to have them replaced.

The correct Bilstein part number for the Z4M is 48-141635. I found that searching online using the part number gave me more results. I ordered mine from schmiedmann.com with a 10% discount. Delivery took about 3 months so I guess my set was freshly manufactured.

These coilovers require some original parts to complete the install, see below pics for reference. Of course, you can reuse your old ones but mine were in pretty bad shape so replacing them is strongly recommended. The parts I purchased were:

31-33-1-090-612, front spring plate with axial bearing (2 pieces)
51-71-7-036-781, front strut tower reinforcement plates (2 pieces)
31-33-1-091-233, front upper spring pad (2 pieces)
33-53-1-136-385, rear upper spring pad (2 pieces)
33-53-1-094-518, rear bottom spring pad (2 pieces)
Rogue engineering rear shock mounts - already had these, just had to buy new bushings which are really cheap.

The installation process is straightforward, nothing special to note. My workshop got the job done in less than 2 hours with two mechanics.

I have the damper settings at 3 all round and am pretty pleased. Ran the car through my regular routes with some long sweeping high speed turns and also tighter turns, everything held up well. Read some other reviews which said that the Bilstein coilovers are harsh. As far as coilovers go, I really don't see how much more comfortable they can be. Overall, very satisfied.

On to the pics... Btw, note the size difference for the rear shocks.

[gnx]

Looks good. Are these M763 rims with F80 blue brakes? Do you have spacers up front?

[grannyknot]

Thanks for including the list of the stock parts needed, I also have the H&R set and I'm very pleased with it but all the original parts were discarded before I bought the car.
What springs are you using?

[pcube]

Originally Posted by gnx

Looks good. Are these M763 rims with F80 blue brakes? Do you have spacers up front?

The rims are replicas of the 763, spacers needed for the rear. Kinda difficult to find an original set where I am. Also, the front offset for original 763s may be a little too aggressive.

The brakes are stoptech, just painted blue

[pcube]

Originally Posted by grannyknot

Thanks for including the list of the stock parts needed, I also have the H&R set and I'm very pleased with it but all the original parts were discarded before I bought the car.
What springs are you using?

Just the standard springs that came with the set. Never felt the need to upgrade for street driving.

For the H&R, the original parts required up front are the same as listed previously; while in the back there is no need for the lower spring pad (may not need the upper ones too but I am not 100% sure).

[Westersund]

I see that you still have the fender side roundels installed that you bought from me. Car is looking good!

[mmm-five]

Same set-up I use when I swapped out the OE stuff at 100k miles. It was cheaper to upgrade to aftermarket than buy the compromised OE stuff, and I wanted something 60:40 road-biased (these or KWv3), than more track-biased (e.g. Bilstein Clubsport/Evo or KW Clubsport/Comp).

I decided not to lower the car too much as I have to negotiate a lot of speed humps and the car would already touch some of these at OE height, and my e34 M5 (on Bilsteins as well had already lost one sump due to them).

I have mine at 4-5 in the summer, and 1-2 in the winter (if I remember).

For Nurburgring it's 8 if it's dry and 4 if it's wet. For smooth UK circuits I just crank them all the way up in the dry and only take it down to about 6 if it's damp.

But it's purely personal preference.

[pcube]

Originally Posted by Westersund

I see that you still have the fender side roundels installed that you bought from me. Car is looking good!

Those aren't ever leaving the car haha

[pcube]

Originally Posted by mmm-five

Same set-up I use when I swapped out the OE stuff at 100k miles. It was cheaper to upgrade to aftermarket than buy the compromised OE stuff, and I wanted something 60:40 road-biased (these or KWv3), than more track-biased (e.g. Bilstein Clubsport/Evo or KW Clubsport/Comp).

I decided not to lower the car too much as I have to negotiate a lot of speed humps and the car would already touch some of these at OE height, and my e34 M5 (on Bilsteins as well had already lost one sump due to them).

I have mine at 4-5 in the summer, and 1-2 in the winter (if I remember).

For Nurburgring it's 8 if it's dry and 4 if it's wet. For smooth UK circuits I just crank them all the way up in the dry and only take it down to about 6 if it's damp.

But it's purely personal preference.

Just curious, how discernible are the settings? Does each click result in a significant change in characteristics? Noticed you only have 2 clicks difference between summer and winter settings.

I had a set of HKS coils on a previous car that was set up for the track, and honestly I could barely tell the difference so just ended up leaving it at the maximum stiffness.

[mmm-five]

Originally Posted by pcube

Just curious, how discernible are the settings? Does each click result in a significant change in characteristics? Noticed you only have 2 clicks difference between summer and winter settings.

I had a set of HKS coils on a previous car that was set up for the track, and honestly I could barely tell the difference so just ended up leaving it at the maximum stiffness.

1 click I couldn't really tell, 2 clicks I 'think' I can tell, but I had it on the lowest setting for quite a while to get used to it and kept cranking it up until it felt too poor a ride for UK roads and cranked it down a couple.

For winter - where I don't use it a lot anyway - I just took it all the way down and tried to keep the front/rear variance the same.

Some people just crank them to 10 for all their uses, but mine was a 90% road car for a long time (25k miles a year) and the UK tracks I used were very smooth, so didn't hamper the higher settings. The bumps/kerns at some places on the 'Ring mean I back off a little to avoid too much bounce.

[onebluemcm]

Wanted to say thanks for this. Getting ready to install the same coil overs on my 07 M coupe. 30% off, yep, good time to pick up a set.

To the OP, pcube, what wheel size, offset and tires size when you did this install?

I have 18x9 +38 offset front, 18x10 +27 offset rear with a 245/40 front and 285/35 rear tire. It's on Koni yellow struts/shocks (older Ground Control kit) with Dinan springs, all this stuff was put on probably 10 years ago. The springs I believe are supposed to be a very mild drop, I want to say 3/8"/10mm IIRC.

I've had rubbing from the inside of the rear tires on the upper vertical part of the wheel well liner. Nothing toward the outside near the fender. And I think I am not running enough rear camber based on tire wear pattern, which makes me even more concerned about where the rubbing is happening. Was wondering about your wheel/tire combo for comparison.

[XMetal]

Originally Posted by pcube

Hey all,

I know there are several threads discussing this particular set of coilovers, but there are bits of information all over the place which requires some searching so thought I would share what I did. Hopefully it benefits someone in the future.

Some background. My car is entirely street driven (unlikely it will ever see the track), and my previous set of coils were H&R. They have been on the car for 6+ years and about 60k miles. I remember that they were quite comfy when they were first installed, but recently it seemed like there was zero damping which prompted my decision to have them replaced.

The correct Bilstein part number for the Z4M is 48-141635. I found that searching online using the part number gave me more results. I ordered mine from schmiedmann.com with a 10% discount. Delivery took about 3 months so I guess my set was freshly manufactured.

These coilovers require some original parts to complete the install, see below pics for reference. Of course, you can reuse your old ones but mine were in pretty bad shape so replacing them is strongly recommended. The parts I purchased were:

31-33-1-090-612, front spring plate with axial bearing (2 pieces)
51-71-7-036-781, front strut tower reinforcement plates (2 pieces)
31-33-1-091-233, front upper spring pad (2 pieces)
33-53-1-136-385, rear upper spring pad (2 pieces)
33-53-1-094-518, rear bottom spring pad (2 pieces)
Rogue engineering rear shock mounts - already had these, just had to buy new bushings which are really cheap.

The installation process is straightforward, nothing special to note. My workshop got the job done in less than 2 hours with two mechanics.

I have the damper settings at 3 all round and am pretty pleased. Ran the car through my regular routes with some long sweeping high speed turns and also tighter turns, everything held up well. Read some other reviews which said that the Bilstein coilovers are harsh. As far as coilovers go, I really don't see how much more comfortable they can be. Overall, very satisfied.

On to the pics... Btw, note the size difference for the rear shocks.

Regarding the 51-71-7-036-781, front strut tower reinforcement plates, did you have to modify it to fit our Z4? I was told that we need to either remove the locating pin on the strut hat or drill a hole on the reinforcement plate for the locating pin?

[maupineda]

Yes, you either remove the pin, or modify the plate and drill the hole for the pin. I did the latter.

[onebluemcm]

Originally Posted by XMetal

Regarding the 51-71-7-036-781, front strut tower reinforcement plates, did you have to modify it to fit our Z4? I was told that we need to either remove the locating pin on the strut hat or drill a hole on the reinforcement plate for the locating pin?

I removed the pin on the upper strut support and shoved them as far inward as they would go to get as much camber as possible without camber plates, for now. Yielded -1.95-degrees on both sides, which I think is about right for a street car.

[fryh1n]

Originally Posted by onebluemcm

Wanted to say thanks for this. Getting ready to install the same coil overs on my 07 M coupe. 30% off, yep, good time to pick up a set.

To the OP, pcube, what wheel size, offset and tires size when you did this install?

I have 18x9 +38 offset front, 18x10 +27 offset rear with a 245/40 front and 285/35 rear tire. It's on Koni yellow struts/shocks (older Ground Control kit) with Dinan springs, all this stuff was put on probably 10 years ago. The springs I believe are supposed to be a very mild drop, I want to say 3/8"/10mm IIRC.

I've had rubbing from the inside of the rear tires on the upper vertical part of the wheel well liner. Nothing toward the outside near the fender. And I think I am not running enough rear camber based on tire wear pattern, which makes me even more concerned about where the rubbing is happening. Was wondering about your wheel/tire combo for comparison.

mind sharing the retailer selling for 30% off?

[hyojyang88]

This suspension came on my car when I bought it and i'm not sure of the characteristics. Is your front suspension harsh when hitting a small bump on the road? If i hit a slight bump its sounds like its hitting really hard. I'm curious if the preload was set properly?