B12 Kit - Alpina Roadster Setup

#108 was built in April 2004 originally, rebuilt by Alpina in July 2005. Her suspension is now 11+ years old (apart from the 2 replacement rear springs in 2010) and the shocks were starting to show their age. Rather than going for a replacement OEM which is incredibly expensive, I decided on an upgrade and after polling some other Alpina members (thanks grumpybri & Number5) I ordered a B12 kit from Germany. I know that the front axle weight is low for the B12 kit as the engine is a heavier lump in the RS, but after asking around, I wouldn't notice the difference in road driving conditions, only at the outer limits - and my ability gives out long before the car's

Mid June I received delivery of the B12 kit for the E85 Z4 - great service by the supplier btw, highly recommend using them - purchase link: here



I also decided to replace the top mounts at the same time. In the rear I went for Rogue Engineering top mounts (linky) and in the front I decided to try the Compbrake adjustable top mounts (linky)

As I have been working away recently - and didn't fancy replacing the rears - I gave the whole kit to my local Indy to fit, along with a four wheel tracking. I've now had them on for a couple of weeks and wow - what a difference. The road holding is night & day different; no more wooliness in the corners and a far more grippy feel. There is a small drop in ride height, but nothing too extreme - I do expect it to settle a bit more over the next week or so, and then I'll have another alignment done.

Regarding the top mounts, I'm still not convinced on the Compbrakes. They are a fantastic looking piece of kit, but they are milled aluminium with an adjustable bearing - there were stories about the bearing wearing out after a couple of years, but recently the quality seems to have improved. The design is slightly harsh for a pure road car, but I'm going to give them a few months and see how they bed in.

Oh, and some pics





Rear Height:


Front Height:


How she now sits...

oh wow..... now thats tasty.....

more pics PLEASE!!!!!! looks so exotic , colour, wheels, stance... perfect...

Looks good

Did you lower the height of your front plate?

Looks very good,black wheels against the red bodywork look just right

WOW What a difference they make, fancy them myself now! But I only replaced mine within the last 18 months,

Cheers all, very happy with it, but still got a few things planned over the next couple of years - LSD, paint correction and a full refurb underneath to ensure no corrosion.

Also planning on taking more photos when I take a road trip, Beedub - probably next weekend - as I need a location
srhutch - yep, lowered the plinth to align the bottom line with the top of the vent as I thought the lines looked better.
maxman - totally agree, love red & black
zedwheels - what did you replace on yours?

Now you have driven for a few weeks, can you notice a difference in ride comfort at all?
Also what are tell tell,signs of the old set up getting tired?

Looks fantastic by the way

Thanks Rich-hill. Ride comfort hasn't changed much, I would say its the same as before - spoiled by the crap condition of the roads, especially in Lincolnshire. Despite the slight lowering, the ride isn't any harsher than before, which I would class as "sporty"

Before fitting the new shocks, the big giveaway for me was the feel of the car when going through corners, or travelling at speed - it just didn't feel right. The front end didn't feel engaged, and felt like grip was going as speed increased or on a particularly challenging corner. Lately I was finding that after each run I was checking for broken springs, leaking shocks, broken mounts etc because something just didn't feel right. I had my indy review all the suspension components and steering rack and he agreed with me that the shocks were not performing well.

markeg said:

Thanks Rich-hill. Ride comfort hasn't changed much, I would say its the same as before - spoiled by the crap condition of the roads, especially in Lincolnshire. Despite the slight lowering, the ride isn't any harsher than before, which I would class as "sporty"

Before fitting the new shocks, the big giveaway for me was the feel of the car when going through corners, or travelling at speed - it just didn't feel right. The front end didn't feel engaged, and felt like grip was going as speed increased or on a particularly challenging corner. Lately I was finding that after each run I was checking for broken springs, leaking shocks, broken mounts etc because something just didn't feel right. I had my indy review all the suspension components and steering rack and he agreed with me that the shocks were not performing well.

Click to expand...

Thanks that good to know.

The only reason I ask as my shocks are quite noisy.
Over all bumps with the roof down I can hear ooosh oosh (it is in time with all bumps).
However on previous cars I've never been able to hear this

I've only just licked up on this thread !

I'm glad your pleased with the change Markeg. I Dont know any different as #019 has always had the B12 kit on since I've had it, but I wouldnt change it. It corners lovely and the ride is ccmfortable, yet sporty.

Good luck with it going forward.

Hi all. Apologies for the thread resurrection but can anybody confirm that it's the 46-181237 bilstein B12 kit that the alpina's require? I think it's time for a suspension refresh and this appears to be the kit of choice!

I put the Bilstein B12 kit on my car also, its a really nice setup i must say! Wasn't too pricey either. I can't remember the part number for the kit off by hand, I think i got the Kit from Ebay from a Germany company.. Let me know if you still need the info and i will look back in my history for you.

It's all good. I've gone ahead and ordered the kit. I'm pretty sure it's the correct one...!

Appreciate the offer though

Looks an absolute stunner 8) a mod well worth doing by the looks of it