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

[Subfra///Me]

Do the Turner Street plates allow enough travel for the B12 kit? I live in the south. Roads are pretty good overall here.

If I recall correctly, Koni/Dinan doesn't even require the use of plates.

[K-Dawg]

The Turner plates give you just under 10mm extra travel. Not a whole lot! I just spent a bunch of time measuring mine this weekend Ground Control might be better

edit: Does anyone in here have stack measurements for Ground Control? Pics of stock and Turner (add the spacer for Turner numbers)

Yes, I actually just finished taking measurements of new OE strut mounts, Turner Street, Ground Control Street, and Turner Hybrid mounts. Besides stock, Turner Street is the worst for bump travel (especially with the spacer). Turner Hybrid is the king. I'm putting the information together for a separate post.

[Bry5on]

The Turner plates give you just under 10mm extra travel. Not a whole lot! I just spent a bunch of time measuring mine this weekend Ground Control might be better

edit: Does anyone in here have stack measurements for Ground Control? Pics of stock and Turner (add the spacer for Turner numbers)

[Subfra///Me]

Does anyone here have real world experience with BOTH the B12 kit and Koni/Dinan?

I understand that the B12 kit is a performance upgrade over the Koni/Dinan combo, but is the increase in performance greater than the decrease in ride comfort? I know this is very subjective, but looking for opinions.

My car is a weekend/fun car and will only occasionally see track or autocross time, so I don't want it to ride like hell. I will be using Turner street camber plates, so I don't think travel should be an issue with either setup.

From what I've read here, it seems like Koni/Dinan is an upgrade in both performance and ride quality over stock. The B12 should obviously be an upgrade in performance as well, but what is the ride quality like? Rougher than stock? If so, how much?

[Tbonem3]

I love b6s. You need to mod them / set them up properly to go lower than stock.

They're too stout for oe replacement though, you'd be better off with koni or the b4s which are also twin tube like sachs and konis (more comfortable)

B6s are better when you're increasing spring rate a bit and want more robust control. There is a cost, though. They're a bit rough/firm.

[IamFODI]

I don't know anything about the B6's but that sounds like an interesting option.

IDK what the B6 is like for this platform, but...

Typically the B6 makes the ride slightly firmer than stock but has good body control and a very long service life. If you want to install a set of dampers and never worry about them again for as long as you (probably) own the car, the B6 is usually your best shot.

[cobra]

Your damper options with stock springs are Sachs (OEM), Koni Sport (adjustable rebound damping), Bilstein B4 (OE replacement) and Bilstein B6 (inverted monotube strut and monotube shock).

I don't know anything about the B6's but that sounds like an interesting option.

[K-Dawg]

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.

Your damper options with stock springs are Sachs (OEM), Koni Sport (adjustable rebound damping), Bilstein B4 (OE replacement) and Bilstein B6 (inverted monotube strut and monotube shock).

[Tbonem3]

KYs? You might mean Konis. KYBs dont make dampers for the e46m3 afaik.

Dinan is a mild drop (so you won't be on the bump stops too much), and they provide rebound setting suggestions for the konis.

[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.

[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.

[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.

[K-Dawg]

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

[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]

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.