M5 M6 brakes on Z4 --conversion?

[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.... :roll:

 

[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.... :roll:

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.php?t=798894&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.php?t=798894&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;
https://z4-forum.com/forum/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/

 

[Valor1]

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/

Thank you for all the great information! Much appreciated! Looking forward to this brake project )

 

[Jembo]

Interesting thread & earlier opinions, great exploration, especially the division of opinion whether it’s truly beneficial for a road car where I believe those against aren’t considering one area of (to me) massive benefit.

I often drive on German Autobhans, where you need to be constantly on your guard for a rapid ‘shave’ of speed.

It’s the amount of ‘leg/foot’ pressure that’s key, regardless whether it’s a rapid UK 70-30 deceleration or DE big +100’s stomach churner.

On the two ‘little league’ brake upgrades I’ve done, to me it’s the greater & more effortless speed shaving that makes such a difference... where you exert far less braking pressure for the same effect...meaning you remain in greater control of the car

 

[buzyg]

Interesting thread & earlier opinions, great exploration, especially the division of opinion whether it’s truly beneficial for a road car where I believe those against aren’t considering one area of (to me) massive benefit.

I often drive on German Autobhans, where you need to be constantly on your guard for a rapid ‘shave’ of speed.

It’s the amount of ‘leg/foot’ pressure that’s key, regardless whether it’s a rapid UK 70-30 deceleration or DE big +100’s stomach churner.

On the two ‘little league’ brake upgrades I’ve done, to me it’s the greater & more effortless speed shaving that makes such a difference... where you exert far less braking pressure for the same effect...meaning you remain in greater control of the car

Not sure that I agree completely with you there. Fitting larger brakes to a car without changing the OEM suspension set up is very unlikely, to improve the handling/contol of the car, in any way. However the small loss in handling is more than made up for by the increase in safety and driver confidence, due to knowing you can probably stop quicker than the guy in front. So the feeling of control is certainly improved. :wink:

 

[Jembo]

Not sure that I agree completely with you there. Fitting larger brakes to a car without changing the OEM suspension set up is very unlikely, to improve the handling/contol of the car, in any way. However the small loss in handling is more than made up for by the increase in safety and driver confidence, due to knowing you can probably stop quicker than the guy in front. So the feeling of control is certainly improved. :wink:

The debate will no doubt rage on... last one I did was my old 3.0SE with the 330i calliper upgrade, though had poly’d & billy’d most of it before they went on.

Likely new discs & pads always help, made for a more relaxed drive - not bothering with the M as they’re fairly new & for road use, their bite is pretty aggressive, noticibly more than the dinner plates on my Merc & u don’t want to be too close behind that on a full stop

I

 

[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/

Thank you for all the great information! Much appreciated! Looking forward to this brake project )

No problem at all, will be looking forward to seeing what you can do!

For reference, I recently had a day in the new G29 Z4 with the four piston front calipers and two piston rears. The brakes on that car felt almost identical to the M4 calipers on mine, a test drive in the new car will give you a very good idea of what I've done will feel like.

 

[Valor1]

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/

Thank you for all the great information! Much appreciated! Looking forward to this brake project )

No problem at all, will be looking forward to seeing what you can do!

For reference, I recently had a day in the new G29 Z4 with the four piston front calipers and two piston rears. The brakes on that car felt almost identical to the M4 calipers on mine, a test drive in the new car will give you a very good idea of what I've done will feel like.

Thanks. Be nice to drive the Z4 E89 and G29 back to back. As the steel brakes from the M5 fit I'm thinking better option to keep weight down is to go with the carbon ceramic M5/6 brakes

 

[mcbutler]

Too much focus on the brakes as the primary stopping mechanism, what about the tyres?
Lets not forget the larger tyre footprint of the M card combined with greater weight matches the braking power.

Once you mess with this you destroy the balance built in by the manufacturer so careful consideration is needed.

Like fitting wider tyres, the weight of the vehicle across the tread is reduced by the larger area so less downforce to get grip in the wet!!

just a thought..

 

[Jembo]

Too much focus on the brakes as the primary stopping mechanism, what about the tyres?
Lets not forget the larger tyre footprint of the M card combined with greater weight matches the braking power.

Once you mess with this you destroy the balance built in by the manufacturer so careful consideration is needed.

Like fitting wider tyres, the weight of the vehicle across the tread is reduced by the larger area so less downforce to get grip in the wet!!

just a thought..

Quality tyres & knackered shocks are just as dangerous.... as are cracked springs, arbs & worn bushes....so many things.

Certainly a bigger picture consideration , though IMO easier to follow any thread if remains on topic

 

[mcbutler]

Too much focus on the brakes as the primary stopping mechanism, what about the tyres?
Lets not forget the larger tyre footprint of the M card combined with greater weight matches the braking power.

Once you mess with this you destroy the balance built in by the manufacturer so careful consideration is needed.

Like fitting wider tyres, the weight of the vehicle across the tread is reduced by the larger area so less downforce to get grip in the wet!!

just a thought..

Quality tyres & knackered shocks are just as dangerous.... as are cracked springs, arbs & worn bushes....so many things.

Certainly a bigger picture consideration , though IMO easier to follow any thread if remains on topic

Agreed..

 

[Player 1]

Thank you for all the great information! Much appreciated! Looking forward to this brake project )

No problem at all, will be looking forward to seeing what you can do!

For reference, I recently had a day in the new G29 Z4 with the four piston front calipers and two piston rears. The brakes on that car felt almost identical to the M4 calipers on mine, a test drive in the new car will give you a very good idea of what I've done will feel like.

Thanks. Be nice to drive the Z4 E89 and G29 back to back. As the steel brakes from the M5 fit I'm thinking better option to keep weight down is to go with the carbon ceramic M5/6 brakes

That'd be an excellent setup if you can get it all together! I didn't do any weighing but the M5 calipers I had felt marginally heavier than the standard Z4 calipers which themselves were noticeably heavier than the M4 calipers.