R56 JCW Brembo calipers are the most beautiful among all R56/F56 MINI calipers for my taste. Their main downside is narrow OE 316x22 mm (12.44”x0.86”) brake discs. The OE discs’ ability to dissipate heat is limited by the narrow ventilation air gap. At the same time R56 Brembo calipers have right brake pads. The pads provide wide friction track (55,6 mm) on the discs and thus substantially bigger disc friction surface than the majority of aftermarket BBK for MINI, even with bigger diameter discs. People usually buy the diameter of the discs as it is the most visible and understandable discs’ characteristic. Not all people even pay attention to the width of the discs. And very few people pay attention to other also very important parameters. One of the most underestimated parameters is the size of friction surface/annulus of the discs. The bigger the surface is the lower its peak temperature is during extreme hard braking from high speed. Heat has some time lag in spreading throughout the internals of the discs – that’s why big friction surface is important. Thus OE calipers and pads have very good potential. To unlock this potential JCW calipers need discs that can not only absorb high volume of energy but also dissipate it quickly to be ready for the next hard braking.
The most cost-effective upgrade for JCW Brembo calipers is to pair them with 315x28 mm (12.4”x1.1”) BMW M3 E36 discs. The disks have curved directional vanes and 13.5-13.75 mm air gap, they are cheap (at least one-piece) and easy to buy. They are light – 7,4-7,7 kg for one-piece, two-piece discs weigh about 7 kg. JCW 316x22 discs weigh 7,4-7,5 kg. The drilled one-piece Zimmermann is lighter (7,4 kg) than other one-piece discs. It has a bit wider air gap (13.75 instead of 13.5 mm) and wider air intake.
To place BMW discs on the hubs I use 7.5 mm steel spacers. The weight of each steel spacer is 0.35-0.5 kg. The spacers with open windows are lighter and provide ventilation of the hubs. I prefer galvanized steel brake disc spacers since they provide better heat protection of the hubs and they are more durable and predictable than aluminium spacers. The weight difference between aluminium and steel spacers is minimal. This weight is concentrated near the centre of rotating mass and its influence on dynamics is negligible.
To work with 28 mm discs the calipers require 6 mm insets, additional seals and longer high-strength screws. Two screws are enough for one caliper. Two OE screws can be reused. The modification of pad springs is also required – they should be 6 mm wider.
The caliper gets 6 mm wider and the brake disk spacer is 7.5 mm wide. So no wheel spacers are needed. The wheels are centered on the hubs. JCW calipers are very tolerant to X-factor of the wheels. Usually big brake kits with 28 mm wide discs require big wheel spacers.




BMW M3 brake discs 315x28





316x22 vs 315x28







7.4kg vs 7.7kg



Wide air intake



Standard air intake



Brake disc spacer



Vented brake disc spacer







Brake pad springs

 

If to add 8 mm wheel spacers it is possible to use my 16x7 ET45

wheels with JCW Brembo. It equals to usage of 9.5 mm spacers with not modified calipers. But the gap between the wheel and the caliper is only 1 mm. Good tight wheel centering rings should be used.

16x7 ET45









17"

 

Thanks for posting this. Will give this a shot the next time I have to replace my rotors. Will have to identify some parts sources in the mean time.

 

One more important detail to unlock the potential of JCW calipers - stainless steel vented brake pistons. They are must have for track high temperature application.

 

looks great and nice write up!

 

Nice job, but is there any other route I can take? I am looking for nice stock sized 316mmx22mm rotors.

 

??
you could not do any of this and just bolt up the jcw calipers with stock jcw discs...there are plenty in all variety (solid/drilled/slotted/dimpled/etc) from good manufacturers in the stock sized rotor

 

Hi,I have been looking for 316x22 Brembo discs, and cannot find any for sale here in the states, apparently they are number FD215000, has anyone have any info on them?
http://www.vendiloaosta.it/gb/mini-m...per-works.html