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

[0-60motorsports]

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?

Hey were you able to dial in 13" ride height in the rear with the PSS10s?

[OldRanger]

How long are each of those springs out of curiosity?

Do you want me to measure the length of the material?

if just simply the vertical dimension:
- Ohlins are both 5 1/8”
- TCK one is 6”, one is 6 1/8”

[cobra]

Obioban I’m going to compare the Ohlins 628# rear to the TCK 700# rear paired with the Ohlins 400 fronts for on track duty with Intermediate drivers.

This Ohlins 628# stack (as set by RRT) measures to 6.5” inches and results in a 13” ride height. The TCK 700 stack is different. When the perch is fully lowered on the threads of the TCK ride height adjuster, this spring g has a 6.5” stack at the highest point of the coil, note that coil is not wound as flat at the top as the Ohlins.

I’m going to try these rear springs now.

I have a new GC front sway that I’m going to keep soft or medium soft. I have a square wheel setup with 265s and a -2.5 camber front -2.2 rear. On Tuesday I have an alignment and corner balance and asking for a bit more negative camber front.

Note: TCK springs do not pair well with the Ohlins plastic

How long are each of those springs out of curiosity?

[OldRanger]

Obioban I’m going to compare the Ohlins 628# rear to the TCK 700# rear paired with the Ohlins 400 fronts for on track duty with Intermediate drivers.

This Ohlins 628# stack (as set by RRT) measures to 6.5” inches and results in a 13” ride height. The TCK 700 stack is different. When the perch is fully lowered on the threads of the TCK ride height adjuster, this spring g has a 6.5” stack at the highest point of the coil, note that coil is not wound as flat at the top as the Ohlins.

I’m going to try these rear springs now.

I have a new GC front sway that I’m going to keep soft or medium soft. I have a square wheel setup with 265s and a -2.5 camber front -2.2 rear. On Tuesday I have an alignment and corner balance and asking for a bit more negative camber front.

Note: TCK springs do not pair well with the Ohlins plastic

[cobra]

Has anyone done this with JRZ's? I bought a set of RS Two's and am looking for some springs to complete the kit. Perhaps overthinking it but I'm wondering if there could be issues up front with such a soft spring if the damper is valved for a higher rate.

I mean Cobra built his off of Fox's with piggy backs, so yes. You just have to get them tuned for your application. I grasp it enough to understand the spring rates, but tuning a shock to your needs that's a whole different science and I paid FCM for this.

You would probably need to revalve if you change the spring rate too much. There is some wiggle room with the adjuster but once you get out of that range you will not be properly matched anymore. In my experience with basic valving, a standard architecture, and single bi-directional shaft adjuster, you can go about +/- 10% in spring rate before it gets noticeably compromised.
That is, of course, assuming it was tuned properly in the first place.

[Cronenberged]

Has anyone done this with JRZ's? I bought a set of RS Two's and am looking for some springs to complete the kit. Perhaps overthinking it but I'm wondering if there could be issues up front with such a soft spring if the damper is valved for a higher rate.

I mean Cobra built his off of Fox's with piggy backs, so yes. You just have to get them tuned for your application. I grasp it enough to understand the spring rates, but tuning a shock to your needs that's a whole different science and I paid FCM for this.

[bavarian3]

Has anyone done this with JRZ's? I bought a set of RS Two's and am looking for some springs to complete the kit. Perhaps overthinking it but I'm wondering if there could be issues up front with such a soft spring if the damper is valved for a higher rate.

[bigjae46]

So what would be a good option if I'm trying to keep it relatively close to stock? I'm just looking for a slightly lower ride height (less than 1") and less body roll. I only track a handful of times a year so I'm not ready to commit to a 5k MCS/JRZ setup, and it is a daily and canyon car as well. TCK S/A or koni yellows paired with dinan springs (I think this is ez flat ride?) are what currently what I've narrowed it down to from my research, but open to suggestions.

I have the TCK x2s with their 450lb springs in the front. My front ride height peaks at 13.75" from fender to the center of the wheel with -4.0 camber. I know if you run less camber then your ride height will change, forget which way. The adjusters are near the top, I can maybe squeeze another 1/4"? Not sure how close to stock that would be. I have a finger width gap between the tire and fender.

The rear is easy, I could probably be a half inch higher than stock.

[IamFODI]

Not plug and play though. They aren't flat ride (though you can do the math and spec them with different springs through 3DM) and you need to mess with ride height adjustment a bit to get bump/droop travel into acceptable ranges.

Fair enough.

[heinzboehmer]

Öhlins.

Not plug and play though. They aren't flat ride (though you can do the math and spec them with different springs through 3DM) and you need to mess with ride height adjustment a bit to get bump/droop travel into acceptable ranges.

[IamFODI]

So what would be a good option if I'm trying to keep it relatively close to stock? I'm just looking for a slightly lower ride height (less than 1") and less body roll. I only track a handful of times a year so I'm not ready to commit to a 5k MCS/JRZ setup, and it is a daily and canyon car as well. TCK S/A or koni yellows paired with dinan springs (I think this is ez flat ride?) are what currently what I've narrowed it down to from my research, but open to suggestions.

Öhlins.

[gaiakai]

So what would be a good option if I'm trying to keep it relatively close to stock? I'm just looking for a slightly lower ride height (less than 1") and less body roll. I only track a handful of times a year so I'm not ready to commit to a 5k MCS/JRZ setup, and it is a daily and canyon car as well. TCK S/A or koni yellows paired with dinan springs (I think this is ez flat ride?) are what currently what I've narrowed it down to from my research, but open to suggestions.

[cobra]

Pretty sure it's a lie. Someone stuck them on a shock dyno, and they were the same. Seems like the only thing that is dinan specific is the setting (which you can recreate for free).

The funniest part is they come with a label that says they are pre-set to Dinan custom specifications (I think it was something like 1/4 turn in front and 1.5 turns in rear) when you order them, but when I checked they were at full soft.

[Obioban]

I have the "Dinan" Konis. No way to tell if they're actually different other than hearsay on the forums, without testing them side-by-side on a shock dyno.

When I asked Dinan directly 10 years ago, they told me they were different. So that's either ignorance or a lie.

Pretty sure it's a lie. Someone stuck them on a shock dyno, and they were the same. Seems like the only thing that is dinan specific is the setting (which you can recreate for free).

[cobra]

Anyone try the Koni set up by Dinan? Just seen them as i was putting the regular koni with stock springs on my cart. They say it lowers with same geometry and same feel has out the factory with the Dinan springs.. but not sure. I personally deal with all weather conditions so it's probably best not to drop at all for me.

I have the "Dinan" Konis. No way to tell if they're actually different other than hearsay on the forums, without testing them side-by-side on a shock dyno.

When I asked Dinan directly 10 years ago, they told me they were different. So that's either ignorance or a lie.