Upgrading brakes, what to do about the rear?

InnovativeAuto

Specialist
Mar 14, 2018
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Z4
Looking to upgrade my brakes in my 35i as I have noticed some fade and my rotors seem to be warped already! After doing a FBO+ upgrade I think the stock brakes have got to go! My plan of action is to go with some 35is calipers, which are the same as 335i and a set of Hawk pads.

From my readings it looks like the 35is rotors are identical to the 335i’s with the exception of being a 2-piece design which has a few advantages (lighter/cooler).

Question is what to do in the rear? Do I need to run 35is calipers/rotors or stick with the 35i setup? With the electric brake it really limits options.
 

Asbjorn

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Mar 10, 2018
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I went with the PB brakes. They install with the oem actuators to maintain the electric brake. The 35is / EUR 35i rear setup is an easy alternative (what I came from). I posted some pictures in my build thread.

I agree that the 35is / EUR 35i front setup is less likely to warp. I used them for light track sessions and they were OK.

As for fade I would say there are three types
Mushy pedal = brake fluid is cooking, and you need to upgrade/flush the fluid.
Firm pedal, but no brakes = brake pads have overheated, and you need a more sports oriented pad.
Warping = Discs are too small... you can consider two piece, and next step is floating as well as added cooling.

Last step is to go ceramic hahaha
 
Last edited:

fmorelli

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Aug 11, 2017
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E89 Z4 35i, F10 535d
An inexpensive solution for the rear is to go to Power Stop rear rotors (drilled/slotted) and EBC yellow stuff pads. This worked well for me. In the front I put the BMW/Brembo performance brake it from BMW (p/n 34110444738). This is $1,129 from BMW of Fairfax. I don't know what it costs to do 35is brake upgrades so I can't speak to the trade-offs. But you can always try what I did on my 35i in the rear (it won't cost much) and see if that works for you. Everything bolts up and works great. There are other front brake solutions, too. There is a thread on E89post on this but I can't find it. In my case I also installed brakes lines from UUC.

Total cost in parts in my case was just under $1,500. Use a good quality brake fluid, like Motul.

This photo is with a 19" wheel. Clearly you can run these brakes with a smaller diameter wheel.
YbAwLUD0kFF8ax6waaXweI8A1oUg3sRcGGNiQROJXLwG5qR0WoKJLlzksT3tWCnkzMJmNsGiS87Wg3OWnQQ=w480-h640-no.gif


Hope this helps you in some way!

Filippo
 

Asbjorn

Lieutenant
Mar 10, 2018
811
552
0
European, based in China
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Z4 N54 DCT
An inexpensive solution for the rear is to go to Power Stop rear rotors (drilled/slotted) and EBC yellow stuff pads. This worked well for me.

Do you know how much wider these rear rotors are over stock? Extra mass and cooling would help against warping, and even the 35is rear rotors are not super wide.

Also, and I am sure you already know, but just so others are also aware: The yellowstuff pad compound features a very high coefficient of friction. In general it is not recommended to move brake bias significantly backwards compared to OEM, which would normally happen with yellowstuff rear and OEM pads front. As you have increased the front rotor diameters, and are using bmw performance pads(?), I am sure it is a more balanced setup.
 
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fmorelli

Major General
Staff member
Aug 11, 2017
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E89 Z4 35i, F10 535d
Good point ... from his post I'm assuming he's changing front pads to more aggressive at a minimum. I don't know if there is a thickness difference.

Filippo
 

NoQuarter

Major
Nov 24, 2017
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Indiana, USA
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Z4 35is, 535xi, X5 35i
It looks like someone is doing an M5 6 piston big brake install. CNC work being done for the bracket. Wish we could get that guy over here instead. Hes on e90post Z4 section

I'm looking over there... it is an E90 forum and I don't see where to switch models?
 

fmorelli

Major General
Staff member
Aug 11, 2017
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E89 Z4 35i, F10 535d

NoQuarter

Major
Nov 24, 2017
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Indiana, USA
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Z4 35is, 535xi, X5 35i
Last edited:

doublespaces

Administrator
Oct 18, 2016
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2009 E93 335i
Thanks... I assumed this was at E89post but didn't dig too far.

edit...
Sent him an invite

bimmerpost censors this URL, so there is a chance he didn't get it unless you've obfuscated it. The easiest is to use goo.gl to mask it.
I can't f'ing believe there is an active thread on e89 about programming your garage door opener. And it's freaking 2 pages long!

I just went over there, and wow. They really mismanaged the node selection. They should have let you guys share an engine room with everyone else with an N54. On my Ecoboost groups, I even stick the Mustang and Focus RS guys together and that is far different. If the engine section was crazy busy, then I could understand the move, but it doesn't look like that was ever a super popular section.

I also checked out their 1M board, another niche group:
upload_2018-6-6_0-41-31.png


Its even worse. This is about as segregated as you can get. Its great if these are busy sections, but its clear that it never was.
 

NoQuarter

Major
Nov 24, 2017
1,605
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0
Indiana, USA
Ride
Z4 35is, 535xi, X5 35i
I think I got it through. I forgot to include a title/subject so the message came back with an error and the site name was already stripped out. I was able to change it and submit until it was no longer stripped then I added a subject line.
 
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Vetracr

Private
Mar 16, 2018
40
16
0
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BMW Z4
Looking to upgrade my brakes in my 35i as I have noticed some fade and my rotors seem to be warped already! After doing a FBO+ upgrade I think the stock brakes have got to go! My plan of action is to go with some 35is calipers, which are the same as 335i and a set of Hawk pads.

From my readings it looks like the 35is rotors are identical to the 335i’s with the exception of being a 2-piece design which has a few advantages (lighter/cooler).

Question is what to do in the rear? Do I need to run 35is calipers/rotors or stick with the 35i setup? With the electric brake it really limits options.

I track my car and still run stock rear brakes as they provide little braking on track due to weight transfer. I upgraded the front brakes to 335i calipers and rotors. I also run Cool Carbon ST brake pads. Combination works fine. Best upgrade for the money.
 
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NoQuarter

Major
Nov 24, 2017
1,605
1,003
0
Indiana, USA
Ride
Z4 35is, 535xi, X5 35i
I track my car and still run stock rear brakes as they provide little braking on track due to weight transfer. I upgraded the front brakes to 335i calipers and rotors. I also run Cool Carbon ST brake pads. Combination works fine. Best upgrade for the money.

I haven't paid much attention. Are those an upgrade from the Z4 35is also?