e46 M3 suspension setup, or how to not downgrade your car with suspension mods

[Obioban]

The PSS10s basically need to be run at stock ride height to function properly. 13.5/13 is too low for them.

[BigRussia]

Interesting, so basically leave the rears well alone as is and don't bothering trying to lower anymore. And maybe raise the fronts more to at least 13.5"?

Ugh, that's not gonna look great. I really liked the lowered wide looks my car had before with the obviously worse performing ST coilovers it came with, but as its a more track and driving focused car now I'd gladly take my suspension working better on track if that's the case!

[Tbonem3]

If you have camber plates, you can get a little lower than with stock mounts, and not lose travel.

[K-Dawg]

Interesting, so basically leave the rears well alone as is and don't bothering trying to lower anymore. And maybe raise the fronts more to at least 13.5"?

Ugh, that's not gonna look great. I really liked the lowered wide looks my car had before with the obviously worse performing ST coilovers it came with, but as its a more track and driving focused car now I'd gladly take my suspension working better on track if that's the case!

Riding around on the bump stops probably isn't best.

In the rear...change your springs, and get something stiffer in the process.

Are you using stock strut mounts in the front? You can gain over an inch of bump travel with certain aftermarket camber plates (Turner Hybrids are the best I've seen in this regard).

Either way, lower isn't necessarily better for performance, but many of us sacrifice performance for looks.

[BigRussia]

My issue is only with the REAR heights, the front is non-issue and can go almost another .5" lower from the current 13 1/4" front height. But since the rears threads max out at same 13 1/4" height my rake is off. (If it matters I'm on GC Street camber plates, but with the BMW reinforcement plates so prob a net gain of travel/height since the plates are like 2-3mm thick).

Riding around on the bump stops probably isn't best.

In the rear...change your springs, and get something stiffer in the process.

Are you using stock strut mounts in the front? You can gain over an inch of bump travel with certain aftermarket camber plates (Turner Hybrids are the best I've seen in this regard).

Either way, lower isn't necessarily better for performance, but many of us sacrifice performance for looks.

Yeah that's basically what I'm asking lol; I am wondering if swapping the REAR PSS10 springs for the Clubsport springs will net me some more lowering and stiffer spring rates at the same time. Or can I just put any other spring, can someone confirm if the PSS10 spring diameters are shared with other brands springs? Or if anyone has changed the springs on their PSS10s what did they use? As it doesn't seem Billstein will sell the Clubsport rear springs separate

[Tbonem3]

PSS10 like all euro stuff is 60mm

[dl.m3]

Interesting, so basically leave the rears well alone as is and don't bothering trying to lower anymore. And maybe raise the fronts more to at least 13.5"?

Ugh, that's not gonna look great. I really liked the lowered wide looks my car had before with the obviously worse performing ST coilovers it came with, but as its a more track and driving focused car now I'd gladly take my suspension working better on track if that's the case!

I would try removing the rear collars completely and just running the spring. But still make sure you use the spring pad or reinforcement to distribute the load on the spring contacts.

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[cobra]

Not sure if this is the right place to propose my question/issue but figure better than making a separate thread since alot of it relates to Obioban's OP info:

My car is on the Bilstein PSS10 (B16) coilovers. I'm trying to get to a proper 13.5" front 13" ride height with the .5" rake, but the rear doesn't go any lower than 13 1/4" even with the rear adjuster collars to max low. With fronts also being at 13 1/4" i basically have 0" rake ands the rear way higher than the front having my car looks like a drag muscle car lol. Only way i can get rears lower is if I remove the rubber spring pads (top is already thinnest BMW makes at 5mm) or just run with no collars (but then defeats the point of having height adjustablitlity for corner balancing). While the car rides great at the higher height I would just really like to get the rear 1/4" lower mainly for aesthetics as the car looks silly with over the top rake it has now and the wheel/fender gap is pretty ugly, almost looks like a stock height car.

I was wondering, has anyone tried getting ahold of the Bilstein Clubsport coilover rear springs and swapping them over into their B16s? Looking at the pics online and eyeballing them side by side the Clubsport rear springs seem to be shorter than the B16's. I figure some stiffer spring rates wouldn't hurt for track days either. I tried finding the springs online but doesn't seem Bilstein sells them separately

Has anyone had this issue with their Bilstein PSS10 B16 and rear just not lowering much or enough? And what is another solution I can try that doesnt involve removing the upper and lower rubber spring pads or the adjuster collar? As you can tell its been driving me a bit crazy, every time I walk into the garage and see how jacked up the rear is and that ugly gap 😅 I know im being OCD but I feel like we are an OCD bunch here eh?

Can you measure the following, it will tell me more about how much you should (or shouldn't) lower the car.
-Length of your PSS10 shock body from the center of the lower mount to the top of the body (where the bump stop hits)
-Bump stop length
-Shaft length fully extended from the body to the shoulder that touches the upper shock mount.

On the PSS10 isn't the adjuster supposed to go on top (against the chassis)? If so you are usually supposed to remove the rubber pad, and only have a rubber pad on the bottom where the spring touches the aluminum arm.

[BigRussia]

Can you measure the following, it will tell me more about how much you should (or shouldn't) lower the car.
-Length of your PSS10 shock body from the center of the lower mount to the top of the body (where the bump stop hits)
-Bump stop length
-Shaft length fully extended from the body to the shoulder that touches the upper shock mount.

On the PSS10 isn't the adjuster supposed to go on top (against the chassis)? If so you are usually supposed to remove the rubber pad, and only have a rubber pad on the bottom where the spring touches the aluminum arm.

Yeah I can get you those, i might be able to get under the car this weekend.

Yup the PSS10 have the rear adjuster at the top of the spring, and sit against the upper factory 5mm rubber pad sandwiched between the chassis. So making height adjustments is a pain but whatever it's better to take it all out to adjust since you wanna get out any sway bar preload dialed out after adjusting.

And yeah funny enough my car didnt come with the rear upper spring pad and the Bilsteins were initially installed without them, BUT according to the instructions that came with the PSS10s they actually want you to run with both factory spring pads! The upper 5mm pad and the lower rubber pad that sits in the lower arm bucket/well. But yeah removing both pads would net me ~3/8" of lowering, but then its just metal on metal moving around when not loaded, especially on the rough lower arm surface. And if Bilsteins themselves intended for the rear coilovers to be run with both spring pads then i dont want to cause extra wear n tear on the dampers if the height it now lower than they designed/intended.

PS: here’s a couple side pics of the rake, if anyone was curious. Lol full on drag car spec, granted on the TE37s I did botch my tire sizing and the rear tire is just slightly taller so it looks slightly worse. The Apex are 265/35 square all around. Again maybe I'm just crazy ha!

[K-Dawg]

My issue is only with the REAR heights, the front is non-issue and can go almost another .5" lower from the current 13 1/4" front height. But since the rears threads max out at same 13 1/4" height my rake is off. (If it matters I'm on GC Street camber plates, but with the BMW reinforcement plates so prob a net gain of travel/height since the plates are like 2-3mm thick).



Yeah that's basically what I'm asking lol; I am wondering if swapping the REAR PSS10 springs for the Clubsport springs will net me some more lowering and stiffer spring rates at the same time. Or can I just put any other spring, can someone confirm if the PSS10 spring diameters are shared with other brands springs? Or if anyone has changed the springs on their PSS10s what did they use? As it doesn't seem Billstein will sell the Clubsport rear springs separate

Sure, it will go that low statically. But is it good? How much travel do you have at that height? The GC Street plates give you an additional ~14mm (0.56") bump travel compared to OE strut mounts.

[BigRussia]

Just to be clear, again I am not looking go any lower on the Fronts lol. I am solely talking about lower on the Rear height.

[K-Dawg]

Right. My point is that you might want to RAISE the front if you give a shit about performance.

[cobra]

Yeah I can get you those, i might be able to get under the car this weekend.

Yup the PSS10 have the rear adjuster at the top of the spring, and sit against the upper factory 5mm rubber pad sandwiched between the chassis. So making height adjustments is a pain but whatever it's better to take it all out to adjust since you wanna get out any sway bar preload dialed out after adjusting.

And yeah funny enough my car didnt come with the rear upper spring pad and the Bilsteins were initially installed without them, BUT according to the instructions that came with the PSS10s they actually want you to run with both factory spring pads! The upper 5mm pad and the lower rubber pad that sits in the lower arm bucket/well. But yeah removing both pads would net me ~3/8" of lowering, but then its just metal on metal moving around when not loaded, especially on the rough lower arm surface. And if Bilsteins themselves intended for the rear coilovers to be run with both spring pads then i dont want to cause extra wear n tear on the dampers if the height it now lower than they designed/intended.

PS: here’s a couple side pics of the rake, if anyone was curious. Lol full on drag car spec, granted on the TE37s I did botch my tire sizing and the rear tire is just slightly taller so it looks slightly worse. The Apex are 265/35 square all around. Again maybe I'm just crazy ha!

I think the car looks fantastic as is and nicely balanced. Leave it alone?

You won't do any "wear and tear" on the damper by running it lower. The only thing you might wear out is the bump stop if you keep smashing into it.

Keep in mind, 3/8" on the spring pads will lower over 1/2" at the wheel because of the motion ratio.

The reason I asked about the adjuster is that other brands use a very thin (2mm) rubber layer on the adjuster itself just to keep it from damaging the chassis. You could get some rubber sheet and emulate this on your car to get another 1/4" or so. Definitely keep the lower rubber pad though, or you will F up the cast arm and make all sorts of bad noises.

[BigRussia]

I think the car looks fantastic as is and nicely balanced. Leave it alone?

You won't do any "wear and tear" on the damper by running it lower. The only thing you might wear out is the bump stop if you keep smashing into it.

Keep in mind, 3/8" on the spring pads will lower over 1/2" at the wheel because of the motion ratio.

The reason I asked about the adjuster is that other brands use a very thin (2mm) rubber layer on the adjuster itself just to keep it from damaging the chassis. You could get some rubber sheet and emulate this on your car to get another 1/4" or so. Definitely keep the lower rubber pad though, or you will F up the cast arm and make all sorts of bad noises.

Thanks! And yeah I should probably leave it alone and stop messing with the rear suspension so many times, I've already taken out the springs to adjust them with different pads, heights, etc so many times I don't even want to say 😅

And yup good point about the motion ratio with separate springs and dampers height adjustment! Wasn't common knowledge to me before, so found that out myself when I would try dialing the rear height after installing the PSS10s and losing my mind when i would measure the amount I moved the rear height adjusters, and then putting the car down the resulting ride height would change like 1.5x that amount ha.

Thanks again for the input everyone, I might just remove the rear 5mm upper spring pads, and will raise the fronts a few threads to 13.5" and call it a day.

[K_M3]

If I'm looking to keep my stock car as close to stock as possible, is the going consensus still stock springs on KYs? If I'm reading all this correctly the Dinan springs on KYs is too close to the bump stops? I'm doing a full suspension/bushing refresh soon and trying to figure out what direction to go with struts and springs.