Check that the r53 hubs are compatible with the r56 GP2 discs. I'm pretty sure they are the same size, the only difference on the r56 is lug bolts are a different pitch/thread.

They are compatible. The bolt patern is 100x4. If you have stud convertion it won't really matter much, but if you use bolts you would probably end up buying the extended ones.

Yeah, the only difference I found is that the the distance from one hole to the other hole where you mount the adapter to the spindle (on the car) is off by max 2mm. That can be solved by opening the mounting hole on the car just by 1mm on each hole to give enough wiggle room.

I was looking at pads....holy #$%%^#@ they're expensive...$250 for the pads is crazy expensive, but hey I gues thats how it will be. I might be able to find some barely used pads on the 135i forum for cheap, though I would prefer to buy them new (bedding is my concern).

:D Can't wait to piece this all up.

those look really cool, im glad they worked out for ya!

too bad i have to deal with snow or i would totally rock those, i dont think the s heavys would fit those massive brakes

Are you doing anything with the master cylinder? I'm curious about how the pedal will feel with the R53 master cylinder pushing those big calipers.

I'm thinking I'll stick to the r53 master cylinder for now. Later I wil upgrade.

I'm still waiting for someone on the GP2 group to help me out with the rotor height (offset).... That would really help me figure out how easy it would be.

This is with stock r53 rotors on. If you notice, the rotor would touch the caliper slightly. This means that the rotor hat height on the r53 is too "tall," the height being ~22mm, total rotor height ~44mm.

http://www.rockauto.com/catalog/more...887&cc=1430887


Based on this, the rotor hat height is not that "tall" on the GP. This makes me think that the hat height on the GP rotors has to be around 18mm. From the picture on ECS tuning, you can see that the hat even dips a bit into the disc area.

This will help the GP2 guys build their 2 piece rotors.

:)

what are you looking for? hat height? can't get a depth mic or caliper in there without pulling a wheel, so some cheater measuring says 19-20mm ballpark, from the face of the hat to the face of the rotor wear surface.

(specifically, that's 17.445mm + ~2-2.5mm by eyeball...)

I can measure it next time I put it on the lift.

(that's for '13 GP #0425, ~16k miles, front left)

We will just come over and take a look

THANK YOU! :)


That totally confirms my measurments. Spacers are a must if people have any regular Mini wheel, as for most run 7" wide. GP2 wheels are 7.5 wide with some offset.

Conclusion the brakes are a direct fit and the only rotors I could find out there to fit well are the GP rotors. 13" rotors with a 4*100 bolt patern seem almost to be non-existent unless custom fabbed, only 2000 GPs were made so that makes it a small market, though $250 is not bad at all for a pair of rotors.

Once I install them I will be posting pics of what to do and how to do it, a nice little DIY.

THANKS guys, your help has been wonderful!

Manny

manny, if you're not planning on it already - I'd advise adding the GP2 specific master cylinder as well. Thats a -lot- of front volume to move.... I'd love it if someone measures both the non-gp2 and gp2 master cyl to tell us what's different. :)

OTOH, you -might- get a more progressive stroke than stock GP if you use a regular MC.....or you might just get an increase in rear bias..

Out of interest I have a GP2 (dedicated tarmac rally competition car) and a R56 JCW (dedicated circuit racing car). I have put a set of GP2 calipers on the JCW racecar. I decided initially to stay with the stock R56 master cylinder and brake booster to see how it went.

I actually prefer the feel of the brakes with the stock R56 master cylinder and brake booster to the GP2 version. There is better pedal modulation IMHO. The stock GP2 system is very off and on.

Having said that the stock R53 master cylinder is smaller than the stock R56, which in turn is smaller than the GP2, so it may be different with the R53 master cylinder.

I just noticed... The guys at Precision Auto Werks have these brakes on their R53 track car. They might be of some help.
http://www.pawmotorsport.com/
https://www.facebook.com/pawmotorsport

https://fbcdn-sphotos-f-a.akamaihd.n...09857572_o.jpg

https://scontent-a-dfw.xx.fbcdn.net/...96647106_o.jpg

Thanks for sharing! :) So yup, those are the GP rotors, and that totally confirms everything. Good job guys!

Robbo,

I've gotten many different opinions about it and all the brake bias that it could create. I will stick to the r53 for a while, I'm pretty sure I will change my BMC. Since you have track experience I think your input is very important. I won't be tracking the car still, so no hard braking or anyhting for now.

[QUOTE=keen;3997434]manny, if you're not planning on it already - I'd advise adding the GP2 specific master cylinder as well. Thats a -lot- of front volume to move.... I'd love it if someone measures both the non-gp2 and gp2 master cyl to tell us what's different. :)

OTOH, you -might- get a more progressive stroke than stock GP if you use a regular MC.....or you might just get an increase in rear bias..[/QUOTE

Well, I could measure my master cylinder :).

If not mistaken, ther GP2 master cylinder is used on other BMW cars, bigger cars.

I will change the BMC if it comes to that.

Hi guys,

An update to this.

Decided to paint the the calipers red :).

Also just ordered:
Braided brake lines
Caliper pad pins

Need to order:
Disk dust shields for GP2 ( Part #s: 34116772550 & 34116772549 )
Brake pads for 135i
GP2 Rotors (Part #: 34116858071)
Spacers (15-20mm)
Brake fluid (Super blue)


Little by little, but getting there.

Some pics! :)

Anyone know if the 135i calipers fit the 2014 F56??

Ok guys,

So during the weekend I decided to mount the brakes as I already had everything...I thought.
Here are some tips and Cooper & I will develop a nice little write up of how to do this mod if the opportunity comes to you.

The calipers mounts are almost in line with the 135i Caliper brackets. By measuring, each hole was off by no less than 1 or 2 mm between the top and bottom bolt mounts. Cooper and I enlarged the mount hole on the car to fit the 135i caliper bracket with absolutely no problem. They mounted perfectly and seemed to be perfectly set in the caliper rotor spacing.

READ:
We proceeded to mounting the rotor and the caliper with the brake pads like any other brake job, here is where we encountered the problem.

Problem:
The rotor is pressed up against the interior brake pad, and it doesn't allow for the rotor to move once you tighten the caliper mount bolts. DO NOT DRIVE THE CAR LIKE THIS, it will be very scary. :)

Here is the fix:
To fix this I ordered a 3mm 4x100 56.1 mm center bore hub centric spacer to place between the spindle and the rotor, moving the rotor forward a couple of millimeters so that it doesn't push against the interior pad and allows the caliper pistons to spring and the rotor to move freely.

Parts needed for this mod with prices:

1. Braided brake lines for 07+ Mini Coopers (CENTRIC Part # 95034007): $40 shipped from rockauto
2. Caliper pad pins (RAYBESTOS Part # H18056A ): $10 shipped from rockauto
3. Disk dust shields for GP2 (optional if you don't care about the dust):
$43/ea or just about $95 shipped from ECS
4. Brake pads for 135i(CENTRIC Part # 30913710): $80 shipped from Rockauto
5. GP2 Rotors: $300 shipped from ECS
6. Spacers (15-20mm): $40-80 depending on which brand you buy.
7. Brake fluid DOT 4 : $10-15 at your local auto parts, I used Pentosin
8. Extended lug bolts or studs to fit the wheels w/ the spacers: $45 shipped
9. 135i Calipers: I paid around $350 shipped for them, got very lucky. I've seen them on ebay for $600+

10. *I recommend rebuilding the calipers before installing them, the rebuild kits go for $7 for each caliper.


Total (for me): ±$1,000
Total for mod with used calipers from ebay: ±$1,300

Conclusion:

If you reaaaaaally want the GP2 looks on your brakes you can go ahead and do this mod. Otherwise I would recommend just buying some good ole' wilwoods or stoptechs, they go for around the same price and definitely save you the headaches and pains of modifying. I love doing this stuff so it wasn't really a pain for me.


Again, Cooper and I will develop a full guide on how to mount the calipers during the upcoming weeks. :) Motor On!



Note: In no way I'm responsible for any damage to you or your car after doing the modification. You take full responsibility for this project. I am only giving you the information if you want to do this modification.

I have no idea what spindles BMW used for the F56. Sorry!

Some teaser pics
 

You can take a look!

looks great, you should look into some custom two piece rotors, im sure TCE would be able to make them for the people who own these rotors, and would be able to put that extra 3mm clearance into the hat.

Very cool, very innovative, very....time consuming, considering a used Mini specific BBK can be had for less $ in many cases.