[tscdennab]

So, after a long time planning and aquiring the parts, I finally fitted my Bilstein B12 Pro-Kit suspension and the M3 subframe bushings.

Why did I choose these modifications for my car ? My goal is to have a no-compromise street car with maximum drag racing abilities and acceptable tracking abilities. So I need as much grip as possible, and wheel hop minimization/elimination. Also the suspension should not be much stiffer than my current M-Sport suspension. And the whole thing should be reasonably priced.

From my research, I concluded that monotube dampers (as opposed to the stock twin-tube dampers) provide superior grip by being very responsive and having the ability to damp even the slightest wheel movements without any delay, keeping the tires in contact to the ground longer. So I needed monotube for my setup. But most monotube dampers are included in expensive coilovers, and usually the coilover springs are very stiff because these are designed for the track. But I don't want to compromise the street manners of my car, not even one bit.

So Bilstein B12 Pro-Kit, at 550EUR ex. VAT, was my suspension choice.

Driving impressions (with my 17" Run-Flat winter tires !):

I really can't believe how good this setup is. It's like 10 times better than my (ok, 40.000 miles old) M-Sport suspension. I expected it to be stiffer, but in fact it feels much softer around town ! The potholes are handled incredibly well, the car seems to float over them. The M-Sport was crashy and it felt like crap over potholes. In corners the car seems flatter, but I didn't really have the chance to test this ability yet.

Ride height has changed only slightly compared to my former M-Sport suspension, I will let it settle a few days and only after that I will post a picture. It should come like 10mm lower in the rear and 15mm lower in the front compared to the M-Sport.

About the M3 subframe bushings: right now, around town I can't say I feel them. I do feel that the entire car seems very SOLID and composed, maybe they play a role in this. I really hope these bushings, combined with the monotube Bilstein dampers will improve on the wheel hop tendency. But it's still winter-like temperature outside to do any kind of test. What I can say is that there are no extra vibrations/harshness transmitted in the car with the M3 subframe bushings, even with run-flat tires.

Overall, I am extremely happy with my suspension. I managed to actually greatly improve the street manners of my car, while adding grip and sportiness. I was under the impression that any aftermarket suspension is some kind of compromise between performance and street suitability, but it seems that it isn't so.

My only concern is that after I will switch to the summer non-RFT tires, the suspension will feel too soft. I really hope it is not the case.

I will report back in a few days with more impressions especially what it's like to drive on this setup with non-runflat tires.

That's all folks !

EDIT: Some pics of the setup below.

[CJ421]

Nice write-up! This is the first time I'm hearing about this product. Looks like great price/performance. I like the modest drop.

Monotube dampers are undoubtedly the way to go. Better communication with the road and as you noted, they are faster to respond to imperfections.

Do you have an LSD? Those subframe bushings make the biggest difference under WOT. The back end no longer squirms around. I have a Quaife and it works extremely well in combination with the M3 bushings.

[tscdennab]

Some more impressions after installing non-RFT tires/wheels (245/40/18 on 18x8.5ET35 front, 285/35/18 on 18x9.5ET45 rear): the ride is the same, no softening felt. Actually today it felt a bit stiffer than last night. It's just perfect !

I uploaded some pictures in the first post. The pictures are like 16 hours after the suspension was installed, if it would settle about 5mm more in front the drop would be perfect for me.

[CJ421]

Drop looks fantastic.

Aggressive cornering with the non-RFT tires will be a more predictable experience. You can feel when the tires are approaching their grip limit. RFTs give no such clue.

[Fraggy]

Do they use eibach prokit springs?

[tscdennab]

Originally Posted by Fraggy

Do they use eibach prokit springs?

Yes.

[nitehawk]

what are the spring rates for these?

[tscdennab]

Originally Posted by CJ421

Do you have an LSD? Those subframe bushings make the biggest difference under WOT. The back end no longer squirms around. I have a Quaife and it works extremely well in combination with the M3 bushings.

I do have a Drexler clutch-type LSD.

Originally Posted by nitehawk

what are the spring rates for these?

From what I read on the forums, basically the spring rates are almost identical to the M-Sport spring rates, just a bit lowered from the M-Sport. But the dampers are valved stiffer.

http://www.e90post.com/forums/showthread.php?t=235797

[DieselDiner]

Do any of our board vendors offer this set up?

[tscdennab]

Originally Posted by DieselDiner

Do any of our board vendors offer this set up?

Somewhat TireRack does. The B12 Pro-Kit = Bilstein B8 dampers + Eibach Pro-Kit springs. I am not sure if there are any modifications to the dampers or springs, but I looked up the part numbers written on my dampers on the Internet and they seem to be standard B8 dampers.

[DieselDiner]

Originally Posted by tscdennab

Somewhat TireRack does. The B12 Pro-Kit = Bilstein B8 dampers + Eibach Pro-Kit springs. I am not sure if there are any modifications to the dampers or springs, but I looked up the part numbers written on my dampers on the Internet and they seem to be standard B8 dampers.

Thank you for sharing the info. It at least sounds possible to 'back door' this set up, doesn't it? Your review really has me intrigued; my d has sport suspension, and while I like the ride, I'd be happy to improve the handling, which seems to be exactly what you've accomplished. My situation is somewhat complicated, because I'm also going to upgrade to M3 suspension bits (minus the subframe bushings and rear sway bar), and I have the rear camber arms that would allow me to use M3 shocks and springs. So - to really use this set up, I *think* I would end up needing to get the M3 kit versus the E90 kit. I don't know if the front strut mounts are the same, so there's another complication.

Again, thank you for sharing your experience. This set up is very intriguing, and sounds like a good alternative to coughing up even more $$ for a coilover set up.

[engotski]

Did the bilstein b12 pro kit come with matching bump stops or you used stock ones?

[tscdennab]

Originally Posted by engotski

Did the bilstein b12 pro kit come with matching bump stops or you used stock ones?

It comes with it's own bump stops.

[Pynne]

Great write-up - think this would be my choice for future suspension (stock atm).

[Pynne]

Originally Posted by tscdennab

Somewhat TireRack does. The B12 Pro-Kit = Bilstein B8 dampers + Eibach Pro-Kit springs. I am not sure if there are any modifications to the dampers or springs, but I looked up the part numbers written on my dampers on the Internet and they seem to be standard B8 dampers.

If this is the case, then it appears to be a lot cheaper to just order the parts seperately - at least in Europe.

Bilstein B12 Pro-Kit: EUR 665 incl. shipping

Bilstein B8: EUR 264 incl. shipping
Eibach Pro-Kit: EUR 159 incl. shipping
Total: EUR 423 incl. shipping

Savings: EUR 242 (about USD 380).

Is anyone able to confirm that the B12 is only the B8 dampers + Eibach Pro-Kit?

[WWM3]

Originally Posted by tscdennab

Somewhat TireRack does. The B12 Pro-Kit = Bilstein B8 dampers + Eibach Pro-Kit springs. I am not sure if there are any modifications to the dampers or springs, but I looked up the part numbers written on my dampers on the Internet and they seem to be standard B8 dampers.

I can only find Bilstein HD & touring dampers on the tirerack site. This set up interests me and like others I can't find a U.S. vendor for B8s!

[DieselDiner]

Originally Posted by tscdennab

The B12 Pro-Kit = Bilstein B8 dampers + Eibach Pro-Kit springs. I am not sure if there are any modifications to the dampers or springs, but I looked up the part numbers written on my dampers on the Internet and they seem to be standard B8 dampers.

Would you mind posting the part numbers for the dampers (from Bilstein) and springs (from Eibach)? This would probably help those trying to track down a source, since most vendors will be better able to search with specific part numbers in hand.

[tscdennab]

Originally Posted by Pynne

If this is the case, then it appears to be a lot cheaper to just order the parts seperately - at least in Europe.

Bilstein B12 Pro-Kit: EUR 665 incl. shipping

Bilstein B8: EUR 264 incl. shipping
Eibach Pro-Kit: EUR 159 incl. shipping
Total: EUR 423 incl. shipping

Savings: EUR 242 (about USD 380).

Is anyone able to confirm that the B12 is only the B8 dampers + Eibach Pro-Kit?

...those are only the rear dampers, you also need the fronts which cost much more than the rears. And yes, I am able to confirm 100% because I read the part numbers from the dampers and they are the same. And the Pro-Kit springs came in their own box inside the B12 huge box.

[tscdennab]

Originally Posted by DieselDiner

Would you mind posting the part numbers for the dampers (from Bilstein) and springs (from Eibach)? This would probably help those trying to track down a source, since most vendors will be better able to search with specific part numbers in hand.

Part numbers differ for different engines (due to differences in engine weight). It's not like the coilovers. So the best thing is to look up the online catalogues of Bilstein and Eibach - they both have excellent online catalogues.

[Pynne]

Originally Posted by tscdennab

...those are only the rear dampers, you also need the fronts which cost much more than the rears. And yes, I am able to confirm 100% because I read the part numbers from the dampers and they are the same. And the Pro-Kit springs came in their own box inside the B12 huge box.

Ahh okay, then I guess it makes sense anyway

My german aint the best, so actually asked in the German-thread aswell, whether or not the item was a complete set, or only one axis

[Pynne]

Originally Posted by tscdennab

Some more impressions after installing non-RFT tires/wheels (245/40/18 on 18x8.5ET35 front, 285/35/18 on 18x9.5ET45 rear): the ride is the same, no softening felt. Actually today it felt a bit stiffer than last night. It's just perfect !

I uploaded some pictures in the first post. The pictures are like 16 hours after the suspension was installed, if it would settle about 5mm more in front the drop would be perfect for me.

I am really close to buy this setup, as I am currently on stock non-sport suspension with 19" non-rft and finding the ride to be floaty and the car having too much body roll - yet I dont want to compromise comfort as I use the car for DD and about 20.000 miles a year.

Do you have any coilover experience to compare this setup with?

Also I wonder where you bought your B12 kit for EUR 550,00?

[tscdennab]

Originally Posted by Pynne

I am really close to buy this setup, as I am currently on stock non-sport suspension with 19" non-rft and finding the ride to be floaty and the car having too much body roll - yet I dont want to compromise comfort as I use the car for DD and about 20.000 miles a year.

Do you have any coilover experience to compare this setup with?

Also I wonder where you bought your B12 kit for EUR 550,00?

No experience with coilovers, but the spring rates of most coilovers are significantly higher so the shocks must be valved accordingly. However, I read great things about how the KW V1/V2/V3 or Weitec coilvers are tuned. They seem to be pretty confortable (from what I read). If I were to choose coilovers mostly for street, it would be KW or Weitec (or the cheaper AP). They are all identically tuned, but different in quality.

You can find the B12 Pro-Kit for 550EUR ex. VAT here:

http://www.tuningteiletotal.de