I'm almost a year into owning this 09 R57 MCS and decided to upgrade the original stock sport suspension.

The car has 66,000 kms on it, 17" rims, factory LSD and the stock sports suspension.
The handling was fine on the french autoroutes, which are smooth and seamless, yet local roads and any transitions we horrible.

Besides just nose diving on braking and lift upon acceleration it had a very unnerving yaw and skitter over small gaps or transitions from different type of tarmacs.
Full power runs in 1st and 2nd gear created a lot of torque steer, and if you drove over a bump in the process, a violent shimmy left and right.

After getting it up on a lift it was clear the front control arm bushings were warn and would allow the front strut to move 2cm on the right side and 1cm on the left side.
I guess this would create more toe and pull the car either left of right. After disconnecting one of the rear shocks at the trailing arm it was easy to move in and out with little to no force.
The rear trailing arms also had a small bit of play, maybe 3mm or so, at the attachment point to the body.

I decided to get the Bilstein B12 kit ( PN 46-180476 ) as I've had a lot of success with the B8's and B16 PSS9's before.

46-180476 includes 2 x struts, 2 x shocks and 4 x Eibach lowering springs. The Struts / shocks are all unique.

Strut / shocks:

• 1 x 35-142287
• 1 x 35-142294
• 1 x 24-142304
• 1 x 24-142311

Springs:

• 1 x E10-57-002-02-22

I ordered PowerFlex front control arm bushings ( PFF5-101 ) and rear trailing arm inserts ( PFF5-1102 ) too.

Installation time was 8 hours total at a local shop.

3 hours for struts.
2 hours for shocks.
3 hours for control / trailing arm bushings.

They dropped the subframe a few inches to get at the control arm bushing mount.

Once mounted, I took it to a local alignment shop that uses a Hunter alignment system.
They needed to dial in the front toe, camber was within spec.

FL : -0.32* FR : -0.36*
RL : -1.32* RR : -1.22*

No adjustable rear control arms were used for this installation.
Post alignment it tracked dead straight and felt like a completely new car.

I didn't measure the drop with the new springs, but side by side pics show the rear was less than the front, maybe 10-15mm, the front looks like 30mm.

This is my first Mini, so I have no other Mini reference, but it feels as solid and handles like an E46 M3 or an E90 325i with the M sport suspension.
It's firm and progressive under load and is a dream in the curves. Full power in 1st and 2nd yield little to no torque steer, no lift under acceleration and zero nose diving under hard braking.

Turn in is where the biggest difference can be seen. The car just digs in and carves. No body roll and huge grip.
Under full braking and a quick 3rd to 2nd shift you can trail brake and keep pushing the nose around the corner.

The rear never steps out and the worst is does is start to squeal the loaded front wheel a bit. It could be the cheap tires the previous owner put on also. A set of Michelins Pilot Sport 4's may fix this.
With marginal front camber maybe this is expected. With another degree or two of negative camber up front I expect you could get a rear wheel up easily.

Climbing up consecutive switch back curves is an absolute blast. With the DSC off and the turbo spooled up, it rips. Truly go kart handling. No shimmy or jawing at all.

The only down side : driving slow speed ( less than 50kmh ) over local, rough roads. The slower you go the worse the stiffer B12's seem to perform.
I did the same crappy road at 30kmh, 50kmh and 90kmh and it gets smoother and less noticeable with speed.
Something you may have to accept with all sports shocks that are not adjustable.

Speed bumps are actually better. Before the car had little to no damping, so it would jolt up and down the speed bumps and hit the front lip on the road.
None of that at all today.

Was worth the investment.

Here's a few pics:


Before

After

Before

After

Before

After

Hunter alignment

Left rear

Left rear trailing arm inserts

Right rear

 

ADMIN - can delete thread, I duplicated somehow. Thx.