M5 M6 brakes on Z4 --conversion?

[warmasice]

You'll need some retrofit caliper brackets.

FcmkVB8.jpg (169.79 KiB) Viewed 546 times

rBQ8CnP.jpg (224.18 KiB) Viewed 546 times

[Player 1]

I did sell a set of M5/M6 brake calipers to a chap in Belgium where he put them to use on a 1 series track car. To make them fit a set of adaptor brackets had to be made and I believe he also fitted a larger master cylinder although I don't know where that was sourced from I'm afraid.

If it's of any interest, I did fit the front calipers from an M4 to my car in conjunction with 370mm discs (repainted silver because I'm not a fan of the blue or liberal application of M logo's). Of course, they not going to be as strong as the M5 calipers but they are lighter and can be retrofitted using purely OE parts without any custom fabrication which was the big attraction for me as it means easy maintenance going forward.
Over the standard setup they are a big improvement, the brakes feel much stronger and offer far better pedal feel, very similar to Porsche's sports cars. I've not driven it hard enough yet to encounter any fading.

This was the thread I did on them;
viewtopic.php?t=110562

[tintoverano]

repainted silver

hi, what brand did you use for the repaint? cheers

[Player 1]

repainted silver

hi, what brand did you use for the repaint? cheers

Paint came from these guys;
https://www.bcs-automotive.co.uk/

They'll do a kit to whatever colour you ask which includes a basecoat, hardener and lacquer that can be mixed and put in a spray gun.

[john-e89]

Back to the original point of this thread:

Has anyone here tried adapting an M5 / M6 brake set up to the z4?

Just in case you haven’t seen them PB BRAKES do a rear line lock and different size kits for the E89 Valor. Might be of interest to you.

[tintoverano]

repainted silver

hi, what brand did you use for the repaint? cheers

Paint came from these guys;
https://www.bcs-automotive.co.uk/

They'll do a kit to whatever colour you ask which includes a basecoat, hardener and lacquer that can be mixed and put in a spray gun.

lovely, thank you

[GuidoK]

Just in case you haven’t seen them PB BRAKES do a rear line lock and different size kits for the E89 Valor. Might be of interest to you.

Thats an interesting system but I wonder how far that would hold up in a MOT.
To me that looks like a hydraulic line lock, and something in the back of my head says that the e-brake/parking brake is not allowed to use the same actuation system as the normal brakes (for safety reasons).
I remember reading something about this in a thread somewhere on the interwebs on hydraulic parking brakes that are popular in the drift scene. But maybe this is EU regulation so perhaps this issue solves itself in 1½ month....

[john-e89]

Just in case you haven’t seen them PB BRAKES do a rear line lock and different size kits for the E89 Valor. Might be of interest to you.

Thats an interesting system but I wonder how far that would hold up in a MOT.
To me that looks like a hydraulic line lock, and something in the back of my head says that the e-brake/parking brake is not allowed to use the same actuation system as the normal brakes (for safety reasons).
I remember reading something about this in a thread somewhere on the interwebs on hydraulic parking brakes that are popular in the drift scene. But maybe this is EU regulation so perhaps this issue solves itself in 1½ month....

I don’t think you are using the same system though Guidok, the normal parking brake activates the line lock which pressures the calipers so you’re still using the parking system, it’s just that now it’s operating the same caliper as the normal brake system which is a different system. Or am I wrong?

[GuidoK]

I think the normal electric parkingbrake is capable of actuating with the complete system drained of brake fluid. I think this system can't do that. So it's not capable as an emergency brake.
That is I think also the reason you don't see this (afaik) on any production car. Production cars that have aluminium bbk style rear calipers either have a drum inside the rotor hat or they have a separate small extra caliper for the e-brake (this is the system most supercars use)

(afaik the electric parking brake used in virtually all normal cars operates on litreally screwing in or out the existing caliper piston, completely bypassing the hydraulic system. Thats why you have to completely (electrically) unwind the system when changing pads&rotors),

[Raj_UK]

Some good info on this thread

https://e89.zpost.com/forums/showthread ... 894&page=5

He also has a thread on this forum but there’s more info on zpost. That’s my favourite E89. Love it!!

[Valor1]

Some good info on this thread

https://e89.zpost.com/forums/showthread ... 894&page=5

He also has a thread on this forum but there’s more info on zpost. That’s my favourite E89. Love it!!

Thank you Raj....this is a very interesting thread!

[Valor1]

You'll need some retrofit caliper brackets.
FcmkVB8.jpgrBQ8CnP.jpg

Yes!!!! Exactly! Have you fit these to your Z4? How do you like the setup if you have? Who made your brackets?

[Valor1]

I did sell a set of M5/M6 brake calipers to a chap in Belgium where he put them to use on a 1 series track car. To make them fit a set of adaptor brackets had to be made and I believe he also fitted a larger master cylinder although I don't know where that was sourced from I'm afraid.

If it's of any interest, I did fit the front calipers from an M4 to my car in conjunction with 370mm discs (repainted silver because I'm not a fan of the blue or liberal application of M logo's). Of course, they not going to be as strong as the M5 calipers but they are lighter and can be retrofitted using purely OE parts without any custom fabrication which was the big attraction for me as it means easy maintenance going forward.
Over the standard setup they are a big improvement, the brakes feel much stronger and offer far better pedal feel, very similar to Porsche's sports cars. I've not driven it hard enough yet to encounter any fading.

This was the thread I did on them;
viewtopic.php?t=110562

Thank you! Yes, that's my second option. I like the idea of going for the six piston set up and the 400 mm discs along with a matched rear caliper and rear discs for a completely engineered system, albeit for a heavier car.

But its great to hear you can feel the difference even with this set up!

[Player 1]

Thank you! Yes, that's my second option. I like the idea of going for the six piston set up and the 400 mm discs along with a matched rear caliper and rear discs for a completely engineered system, albeit for a heavier car.

But its great to hear you can feel the difference even with this set up!

Not a problem. I can absolutely understand wanting the 6 piston calipers, they are a real work of art in person!
If you google "V8 E89 Z4" and look through the images, you should come across a Blue car owned by a chap in Russia who did exactly what you're after. It may be work looking into his work for details on the master cylinder, unfortunately the rest won't be quite so relevant as he also fitted the rear end from an E46 M3 and front uprights from an E92 M3!

The difference is absolutely night and day, you'd feel the difference just sat still pushing the pedal. Those claiming purely aesthetics are simply not correct.

[Player 1]

Regarding brackets, the guys in Belguim made up a CAD drawing of each one, 3D printed them to test fit before having a set properly machined.
Everyone else I've seen has done something similar to that and was something I looked into before selling the set I had, possible there's a small market there? You will also have to check your inner wheel diameter as some 19'' wheels won't clear the 400mm disc/caliper!

This is the Russian car I meant earlier;
https://www.drive2.com/r/bmw/z4/915819/