With acknowledgment to fmorelli….
Subject is BMW Z4 E89 rear brake upgrades.
The key point is that the E89 was one of the first BMWs to use the TRW integrated electrically operated parking brake which is part of what otherwise is an unremarkable sliding pin single piston rear caliper.
Because of this, its very difficult to find carry over solutions from other cars, like the E90s that carried on using a conventional handbrake.
One option for non 35is owners and for non-european 35i owners is to swap the basic 300mm x 20mm vented disc and caliper for a 324mm x 20mm 35is disc and its caliper. Pad size remains the same.
The only aftermarket rear brake solutions for EMF-based cars (including for the E89 Z4) is made by the Taiwanese firm, PB Brakes and Hong Kong based Ceika..typically at around £2,400 for a 348 mm disc..
From my view the style of their calipers is a bit gauche and really you'd need the front and rears to match which pushes it into a £5k-£6k solution.
There was one well documented US attempt at this by using later G series calipers, its fair to say it turned into an engineering nightmare requiring for example hand cut brake pads to make it work!
There were several cars that used broadly the same system and used 324mm or bigger discs.
The actual emf motor part is common to all these, so although some later cars use a different EMF ECU the motor is still the same..so it should work.
Group (A): F10 550i-x / F06 F11 F12 F13 640/650
Group (B): F06 640 / 650 M-sport
Group (C): G30 530e/i/iX 540i/iX/dX / M550iX / G11 750iX / G12 740i/iX 750i/iX
Group (A) and Group (B) share the same rotor 345mm x 24mm (p/n 34216775289). Basically the rear caliper and brackets are the same across both Group A & B, though B is powder coated black.
Group (C): when coupled with the S2NHA (m-sport) package, has rear caliper (p/n 34216881295) and brackets (p/n 34206891915).
The US attempt was based on Group C calipers and turned into an engineering Vietnam!
However, on another forum I saw a Lithuanian had used a Group A/B caliper together with a different 345mn x 24mm disc from a F 5 series BMW with a different offset and some home made brackets.
The details were scant and the OP now long gone.
I've decided to resurrect this and have a go myself.
So Autodoc have my order now..
Carrier, brake caliper
£59.60
Article №: BDA1027 incl. 20% VAT
Quantity : 1
£59.60
Brake caliper
£125.52
Article №: BHS1190E incl. 20% VAT
Quantity : 1
£125.52
Brake caliper
£110.82
Article №: BHS1191E incl. 20% VAT
Quantity : 1
£110.82
Brake pad set
£56.24
Article №: 2470301 incl. 20% VAT
Quantity : 1
£56.24
Brake disc
£106.55
Article №: 150.3461.52 incl. 20% VAT
Quantity : 2
£213.10
Order total: £629
Brake caliper and caliper carrier are TRW and the discs are Zimmerman coated and drilled. Pads are Textar. One caliper carrier is missing so I've bought a 3rd party one and hope it works out OK.

Subject is BMW Z4 E89 rear brake upgrades.
The key point is that the E89 was one of the first BMWs to use the TRW integrated electrically operated parking brake which is part of what otherwise is an unremarkable sliding pin single piston rear caliper.
Because of this, its very difficult to find carry over solutions from other cars, like the E90s that carried on using a conventional handbrake.
One option for non 35is owners and for non-european 35i owners is to swap the basic 300mm x 20mm vented disc and caliper for a 324mm x 20mm 35is disc and its caliper. Pad size remains the same.
The only aftermarket rear brake solutions for EMF-based cars (including for the E89 Z4) is made by the Taiwanese firm, PB Brakes and Hong Kong based Ceika..typically at around £2,400 for a 348 mm disc..
From my view the style of their calipers is a bit gauche and really you'd need the front and rears to match which pushes it into a £5k-£6k solution.
There was one well documented US attempt at this by using later G series calipers, its fair to say it turned into an engineering nightmare requiring for example hand cut brake pads to make it work!
There were several cars that used broadly the same system and used 324mm or bigger discs.
The actual emf motor part is common to all these, so although some later cars use a different EMF ECU the motor is still the same..so it should work.
Group (A): F10 550i-x / F06 F11 F12 F13 640/650
Group (B): F06 640 / 650 M-sport
Group (C): G30 530e/i/iX 540i/iX/dX / M550iX / G11 750iX / G12 740i/iX 750i/iX
Group (A) and Group (B) share the same rotor 345mm x 24mm (p/n 34216775289). Basically the rear caliper and brackets are the same across both Group A & B, though B is powder coated black.
Group (C): when coupled with the S2NHA (m-sport) package, has rear caliper (p/n 34216881295) and brackets (p/n 34206891915).
The US attempt was based on Group C calipers and turned into an engineering Vietnam!
However, on another forum I saw a Lithuanian had used a Group A/B caliper together with a different 345mn x 24mm disc from a F 5 series BMW with a different offset and some home made brackets.
The details were scant and the OP now long gone.
I've decided to resurrect this and have a go myself.
So Autodoc have my order now..
Carrier, brake caliper
£59.60
Article №: BDA1027 incl. 20% VAT
Quantity : 1
£59.60
Brake caliper
£125.52
Article №: BHS1190E incl. 20% VAT
Quantity : 1
£125.52
Brake caliper
£110.82
Article №: BHS1191E incl. 20% VAT
Quantity : 1
£110.82
Brake pad set
£56.24
Article №: 2470301 incl. 20% VAT
Quantity : 1
£56.24
Brake disc
£106.55
Article №: 150.3461.52 incl. 20% VAT
Quantity : 2
£213.10
Order total: £629
Brake caliper and caliper carrier are TRW and the discs are Zimmerman coated and drilled. Pads are Textar. One caliper carrier is missing so I've bought a 3rd party one and hope it works out OK.

