[W37V]

I am looking to replace my current Bilstein B6 with stock springs for something else. I daily drive my car, and roads here suck ass.

So, I am thinking about doing Bilstein B4 (a bit softer ride) and combining them with Eibach pro-kit springs.

Any advice on this new setup?

[ppointer]

Big fan of B6 and B4. Most of my cars have the B4 which I think is perfect for daily driving. The one car with B6 I never dd. Cannot speak to your choice of spring as mine are all stock.

[W37V]

ppointer I'm big fan as well, but B6 tends to be a bit harsh over rough roads at lower speeds. My commute takes me on GW Parkway, which has really shitty road surface. Combine that with traffic jam, I don't even need coffee in the morning with all the jittering.

[cpie168]

Have you considered Koni FSD's (they're called reds or something like that now)? I have them paired with OEM sport springs and the ride is quite comfortable.

[tlow98]

How much does the Eibach springs lower your car? If more than the OE sport springs than I doubt the 'sport' B4 shocks will last very long.

Have you looked for just OE sport springs appropriate for you model/options. IMO, hard to beat that with any aftermarket stuff...

[W37V]

Originally Posted by tlow98

How much does the Eibach springs lower your car? If more than the OE sport springs than I doubt the 'sport' B4 shocks will last very long.

Have you looked for just OE sport springs appropriate for you model/options. IMO, hard to beat that with any aftermarket stuff...

Average lowering of 1.4" F and 1.0" R

Bilstein combines eibach pro kit springs with their b8 shocks and calls the kit b12. Instead of using b8 shocks, I would use b4 sport shocks instead (which are the same length as b8).

[cpie168]

I heard good things about B6 and B8 before, with them being monotube design and all that. What drives you away from them towards the B4 instead?

[tlow98]

Originally Posted by W37V

Average lowering of 1.4" F and 1.0" R

Bilstein combines eibach pro kit springs with their b8 shocks and calls the kit b12. Instead of using b8 shocks, I would use b4 sport shocks instead (which are the same length as b8).

Yeah, so 0.5inch lower than OE sport. Have you sent an email to bilstein by chance?

[tlow98]

Originally Posted by cpie168

I heard good things about B6 and B8 before, with them being monotube design and all that. What drives you away from them towards the B4 instead?

B6\B8 like anything are great in the right application. As a DD with rough roads they would be pretty tiresome, as in the they ride a lot rougher than a twin tube.

Mono tube is great when they are designed with low gas pressure and low friction, but then they have a short rebuild life, a la Ohlins, etc. If you want them to last 80k+ miles, current technology dictates high gas pressure and high friction seals. This means at low speed they are much rougher riding than a twin tube.

But if you’re doin jumps and stuff, the b6/8 are great!

[cpie168]

Thanks tlow98, appreciate your insights!

[213e90n51]

Wow I was thinking of replacing my B4 struts with B6, i have stock springs and been using B4s for 2 years! Whats with the B6? Was there a difference in the handling capabilities or was it similar? Oh and eibach linear springs is what u want!

[W37V]

Originally Posted by 213e90n51

Wow I was thinking of replacing my B4 struts with B6, i have stock springs and been using B4s for 2 years! Whats with the B6? Was there a difference in the handling capabilities or was it similar? Oh and eibach linear springs is what u want!

Why linear?

Like tlow98 said above.

I was thinking using Eibach pro kit as it is "Progressive Spring Design for Excellent Ride Quality.", aka bit softer ride until pushed hard. Is this not correct? Also, I don't see any product listed by eibach for linear springs for our cars.

B6 can be a bit harsh on rough surfaces. I don't track my car. It is daily driver. I could swap out softer tires, but I don't want to lose that "direct" feel.

[213e90n51]

Originally Posted by W37V

Why linear?

Like tlow98 said above.

I was thinking using Eibach pro kit as it is "Progressive Spring Design for Excellent Ride Quality.", aka bit softer ride until pushed hard. Is this not correct? Also, I don't see any product listed by eibach for linear springs for our cars.

B6 can be a bit harsh on rough surfaces. I don't track my car. It is daily driver. I could swap out softer tires, but I don't want to lose that "direct" feel.

Whats your tire sizes? So for everyday driving b4s are better? I do take corners better but I wanna know if the b6 is really excellent and will be better performer than the B4.

[W37V]

Originally Posted by 213e90n51

Whats your tire sizes? So for everyday driving b4s are better? I do take corners better but I wanna know if the b6 is really excellent and will be better performer than the B4.

B4 should be slightly better than stock sachs shocks. B6/B8 are meant for sport application. The only difference between b6 and b8 is length. B4 comes in two variations: standard and sport. Once again, the only difference is length.

Since most people upgrade their shocks to something else (more aggressive) when doing aftermarket springs, I was curious if anyone actually went with B4 shocks (kept factory shocks) and what was their experience with it.

However, since you asked, my current setup is: (sport suspension from factory)
B6 shocks (ordered wrong ones, for my application should be B8)
Stock springs
M3 upper and lower control arms
Monroe rear shock mounts

Tires are AS3+ size 235/40/18 and 255/35/18. DWS06 are way softer and would make a very pleasant ride. HOWEVER, to me they come off as wobbly and unpredictable.

TBH, when I installed b6 I did notice difference. Car was flatter, but... with speeds less than 40mph, you can feel EVERY bump. I had B6 on my car for almost 50k very hard miles. I think they might be still ok, but they developed some rust issue at the bottom.They don't feel as they used to either.

I could go with b12, but that is not the point. I wanted softer ride, but no compromise in sportiness. Thus, upgrading springs, while downgrading shocks.

[213e90n51]

Originally Posted by W37V

B4 should be slightly better than stock sachs shocks. B6/B8 are meant for sport application. The only difference between b6 and b8 is length. B4 comes in two variations: standard and sport. Once again, the only difference is length.

Since most people upgrade their shocks to something else (more aggressive) when doing aftermarket springs, I was curious if anyone actually went with B4 shocks (kept factory shocks) and what was their experience with it.

However, since you asked, my current setup is: (sport suspension from factory)
B6 shocks (ordered wrong ones, for my application should be B8)
Stock springs
M3 upper and lower control arms
Monroe rear shock mounts

Tires are AS3+ size 235/40/18 and 255/35/18. DWS06 are way softer and would make a very pleasant ride. HOWEVER, to me they come off as wobbly and unpredictable.

TBH, when I installed b6 I did notice difference. Car was flatter, but... with speeds less than 40mph, you can feel EVERY bump. I had B6 on my car for almost 50k very hard miles. I think they might be still ok, but they developed some rust issue at the bottom.They don't feel as they used to either.

I could go with b12, but that is not the point. I wanted softer ride, but no compromise in sportiness. Thus, upgrading springs, while downgrading shocks.

Sweet wow. I want my car to be more flatter in corners but keep the stock height and comfort of my non sport springs. I have bilstein B4s on the car with stock non sportsprings but they wouldnt go well with new sportier springs would they? And r u on oem 18s with 235 fronts? How is it. I have 225 as3+

[DM_e92]

I run eibachs springs with b4s shocks. Been running them for maybe 3 years now. Pretty good match. They may be a tad bit tired now ( the shocks) but definitely still acceptable and not leaking or bouncy. I run 235 35 19 & 265 30 19 if that matters to anybody.

[bluewater328]

Originally Posted by DM_e92

I run eibachs springs with b4s shocks. Been running them for maybe 3 years now. Pretty good match. They may be a tad bit tired now ( the shocks) but definitely still acceptable and not leaking or bouncy. I run 235 35 19 & 265 30 19 if that matters to anybody.

I disagree with this. I have the same setup. They run smooth for normal roads. Hit that speed bump a little too fast or have a highway transition esp from concrete to tarmac with a ride up, you will hit bumpstops. In my case I rub a little on the front too on bad transitions as my 255/35/19 fill up the wheel well perfect, but are subject to rubs as a result of how soft the B4s are.

I've been debating and discussing with others with similar setups. I'd recommend Koni. The AS (RED) will be good for awhile, but the shops are getting too many complaints over time and Koni's official stance to the stores are to not recommend them with lowering springs (even though, yes, they technically could be within spec with Pro Kits). The standard adjustable yellows are what most recommend -- but be warned, even on soft, they are harder than you think (not sure how many states have that 2" oscillation bounce test). B8s will also do a great job, but will be stiffer -- so just depends on what type of ride you appreciate on a regular basis.

[W37V]

Originally Posted by DM_e92

I run eibachs springs with b4s shocks. Been running them for maybe 3 years now. Pretty good match. They may be a tad bit tired now ( the shocks) but definitely still acceptable and not leaking or bouncy. I run 235 35 19 & 265 30 19 if that matters to anybody.

Originally Posted by bluewater328

I disagree with this. I have the same setup. They run smooth for normal roads. Hit that speed bump a little too fast or have a highway transition esp from concrete to tarmac with a ride up, you will hit bumpstops. In my case I rub a little on the front too on bad transitions as my 255/35/19 fill up the wheel well perfect, but are subject to rubs as a result of how soft the B4s are.
In your experience, how was the ride compared to stock?

I've been debating and discussing with others with similar setups. I'd recommend Koni. The AS (RED) will be good for awhile, but the shops are getting too many complaints over time and Koni's official stance to the stores are to not recommend them with lowering springs (even though, yes, they technically could be within spec with Pro Kits). The standard adjustable yellows are what most recommend -- but be warned, even on soft, they are harder than you think (not sure how many states have that 2" oscillation bounce test). B8s will also do a great job, but will be stiffer -- so just depends on what type of ride you appreciate on a regular basis.

How is your ride compared to stock?
I am not looking for stiffer ride. I want smoother ride. Something that will still allow me to experience the sportiness.

I guess the best description of what I am after is how the new X3 or 3 series is. Smooth, capable, corners beautifly without harshness.

[bluewater328]

I think you are between brands. What you probably want is the Koni (RED) Adaptive or indeed the B4, but they won't last you terribly long with drop springs. With stock springs they'd be great and have a comfortable ride with some mild performance.

The next step, like I said, is the Koni Yellow, but that's a bit more harsh than oem sports suspension. Not bad at all, just may be a little too stiff (even with the adjustability) than you're describing.

Compared to stock, B4s are pretty darn close as they were meant to be sports suspension oem replacements.

[MEN54]

Originally Posted by W37V

I am looking to replace my current Bilstein B6 with stock springs for something else. I daily drive my car, and roads here suck ass.

So, I am thinking about doing Bilstein B4 (a bit softer ride) and combining them with Eibach pro-kit springs.

Any advice on this new setup?

I did following and love it, roads here in NY city sucks but i am happy with following setup.

1. Koni Special Acrtive

2. Eibach Pro springs
3. Non Run flat tires, Conti DWS Performance tires

[DM_e92]

Originally Posted by W37V

How is your ride compared to stock?
I am not looking for stiffer ride. I want smoother ride. Something that will still allow me to experience the sportiness.

I guess the best description of what I am after is how the new X3 or 3 series is. Smooth, capable, corners beautifly without harshness.

My ride is definitely stiffer than stock. But I knew it would be. I wanted better handling but didn't want to be race car stiff. So I got the b4s shocks. But it's still comfortable enough. Also u have to change your bump stops. E36 m3 rear and I think in used z4m front can't really remember. I didn't change them at first and after I did my ride was so much better.

[bluewater328]

Originally Posted by DM_e92

My ride is definitely stiffer than stock. But I knew it would be. I wanted better handling but didn't want to be race car stiff. So I got the b4s shocks. But it's still comfortable enough. Also u have to change your bump stops. E36 m3 rear and I think in used z4m front can't really remember. I didn't change them at first and after I did my ride was so much better.

I think you got your bumpstops reversed in your memory: E36 M3 front (part # 31332225377) and Z4 M rear (part # 33507836826) were the ones recommended IIRC.