I wanted to share the big brake kit I built for my X5D.
I have a detailed build thread for my E70 if anyone wants to see more:
https://www.xbimmers.com/forums/show....php?t=1605036
This link has great info explaining different applicable brake systems.
https://f15.bimmerpost.com/forums/sh....php?t=1450854
My X5 tips the scales at 5,000lbs, which is on the lighter side for an E70 but still heavy in general. Now that I have the M57 diesel engine tuned with some other performance goodies power is up to ~370whp 580wtq, factor in the hauling + towing ability, and there are lots of situations where better braking is beneficial. I view this primarily as a safety and performance upgrade.
Essentials
- F10 M5 front calipers + 400mm F10 M5 front rotors
- Porsche Panamera/991.2 rear calipers + 385mm F85 X5M rear rotors
- Custom brackets F/R
High Performance Tuning of brake system for all cars
- Goodrich SS brake lines 6-pieces
- Hawk Ceramic pads
The "easy" upgrade would be to run E70 X5M or F85 X5M brakes since they are bolt-on HOWEVER the E70 X5M front calipers are a dated 4 piston design, F85 is much more appealing as it uses the newer 6-piston monoblock Brembo calipers (same as the F10 M5 calipers I run) but both F85 and E70 front rotors are heavy.
In contrast the F10 M5 rotors are larger (marginally at 395mm vs 400mm) and lighter. The downside is the they require custom caliper brackets to fit the rotors but considering the M5 rotors ~7lbs lighter each, that's a good deal. 7lbs isn't huge but considering that's rotational mass that weight is amplified during acceleration saving 7lbs off each front rotor is roughly equal to 42lbs.
I also run Camaro ZL1 wheels which are forged and relatively light, about 10lbs lighter per wheel compared to the OEM 20" wheels you find on X5 and X5Ms. Do the math on that and my wheel/tire setup is saving about 120lbs of gross weight so I didn't want to shoot myself in the foot by adding unnecessarily heavy rotors.
I wanted to explain all of these weight savings as people keep asking "Why not just install the PNP X5M brakes, why spend more for the adapters"
-Weight, that's why. My wheel/tire/brake setup offers superior braking performance and saves over 160lbs of theoretical gross weight. Not to mention keeping the rotational mass down will further help fuel efficiency, suspension performance, etc. Weight is the enemy for nearly everything performance and efficiency related.
Moving to the rear axle I could have also used stock E70M or F85 calipers BUT the calipers are actually the same as the non-M E70 calipers, just with larger brackets to fit the larger rotor. BMW P/Ns are different to reflect the different bracket (which is part of the caliper and not sold separately) and the black paint (e70) and blue (F85) paint the calipers received. Remove the bracket and paint and the actual caliper is identical between all E70s, F15s, and F85. I am not sure why BMW insists on using ugly floating 2-piston calipers on their $100,000 flagship cars but it drives me crazy. You can spend $15,000 for carbon ceramic brakes on a 2020 F90 M5 and it still uses 2 piston floating calipers. I understand "if it works it works" but there are some standards and expectations. $100k M5s don't come with cloth seats do they? Then why use rear calipers which look like they came from a Nissan Altima?
Obviously I am not a fan of the aesthetics of the 2 piston floating rotor design so I opted to retrofit a Porsche rear caliper, 4-piston monoblock. The calipers needed to be machined and required custom brackets but well worth the effort for the added clamping power and "proper" aesthetics.
Enough of my opinions, onto the pics!
Here is where we started. Calipers were sourced from wrecked M5s and Porsches.
More cleaning
You can see the M5 caliper with the "///M" decal missing has a large gouge that ran the length of the caliper, I assume the wheel broke during the crash, yikes.
Use a metal file to level and smooth out the gouge
I completely disassembled the calipers and one bleed nipple on the M5 caliper wasn't cooperating, more on this later
Next was to get the Porsche calipers machined down
Time for a test fit
The stripped bleed nipple was a real joy to remove but thankfully I was successful. I very carefully bored out the remaining metal from the nipple and used a die to finally remove all material. What a pain.
Calipers were ground, brushed, and sanded down in preparation for paint. Up next was masking.
Primed!
Paint! I used VHT caliper paint. I was thinking of painting the calipers Laguna Seca Blue, British Racing Green, Imola Red, or Rhapsody Blue (Lincoln) but I felt the dark colors would be too ...dark and considering the black/grey theme of my X5 I wanted some contrast. I have put BMW M brakes on 2 of my personal cars already and don't usually use bright colors so I got a wild hair and really wanted something that would pop and grab some attention, I was OK with this as well since my rear calipers are monoblocks and not the fugly OEM floating 2-piston calipers.
Applying Brembo decals ...with lasers! Calipers were clear coated with a high temp clear after this.
Time to clean and rebuild the pistons and seals
I used a Dorman bleeder repair kit. Thankfully with some thread sealant I was able to get everything sealed up
Full Kit laid out
I realized that I painted an area of the caliper I shouldn't have and needed to scrape off the paint to allow some clearance for the brake pads to move freely. Using a chisel followed by some fine sand paper made these areas buttery smooth
Applied a ceramic coating
Goodrich lines. 6 pieces 4 for each corner and the two short ones replace soft lines located on the body by the fuel tank.
OEM front caliper
F10 M5 front caliper
OEM rear caliper
Porsche rear caliper
OEM front rotor
F10 M5 front rotor (Zimmerman)
Oem rear rotor
OEM F85 rear rotor
Time for install
OEM F85 dust shields F/R
Bleeding the brakes. I didn't run the DSC/ABS actuation via INPA/ISTA since it wasn't included in my INPA software and I don't have ISTA
No real worries as all the changes I made were downstream from the DSC pump. Smartwater bottle FTW.
Installed
The bedding process was straight forward with the Hawk pads but I am driving moderately on the brakes for a bit while things continue to get settled.
Here are some additional pics!
