BMW StopTech Brakes

StopTech Brakes for your BMW

StopTech is an enthusiast-driven manufacturer of BMW Big Brake Kits and other performance braking components. Since their beginnings in 1999, StopTech has developed BMW-specific balanced brake upgrades. The company was founded on the belief that the off-the-shelf, "parts bin" approach to BMW brake upgrades rarely gave the the best performance results. A true measured and engineered design for each BMW chassis was the only way to properly advance braking technology.

StopTech engineers evaluate each BMW model's hydraulic system, brake master cylinder size, weight transfer under braking, tire contact patch, and other factors to properly proportion braking torque. Too much braking torque from a poorly-designed system, or re-purposing off-the-shelf parts, could produce sub-optimal results, such as too much distribution to the front axle (or too little). Balancing brake distribution so that all four tires are doing the stopping is hugely beneficial to stopping performance. Every StopTech Big Brake Kit employs this Balanced Brake Upgrade(R).

On this page you will find specific information on StopTech Brakes for your BMW, including wheel fitment guides.

StopTech BMW Big Brake Kit In Detail

What components make up a Big Brake Kit?

StopTech Caliper	StopTech BBK Calipers StopTech produces 2-piston, 4-piston, and 6-piston calipers for BMW applications. Internal pistons are sized for each BMW chassis and intended use. This is the key to the Balanced Brake Upgrade(R) design. By varying piston sizes, StopTech engineers can set the proper brake distribution for maximum traction at all four tires. StopTech calipers are renowned in the industry as being the most rigid. StopTech two-piece calipers are stiffer than even some monoblock caliper designs. A stiffer caliper gives the driver more confidence by reducing flex, vibration, and noise. Less flex also means faster braking response and more even pad wear. StopTech calipers come in blue, black, silver,red, or yellow colors.
StopTech Aerorotor	StopTech BBK Rotors StopTech rotors are so packed with innovations that they patented the design. Aerorotors flow more air and stay cooler than other Big Brake Kit rotors. The internal cooling vanes are specially shaped to to flow more efficiently. Rotors are offered as either slotted or cross-drilled and as bare cast iron or with an anti-corrosion zinc coating.
StopTech Pads	StopTech BBK Pads StopTech Big Brake Kits come standard with a set of Sport pads. These pads are designed as an "aggressive" street compound with excellent initial bite, moderate torque, and low-moderate dust levels. Less-aggressive pads are also available for daily-driver street use. And there is also a wide range of race/track pads available for StopTech calipers.
StopTech Lines	StopTech BBK Stainless Brake Lines Each StopTech Kit comes with two stainless brake lines (enough for one axle). Brake lines are model specific so they have the correct fittings and length for each BMW chassis. Stainless lines replace old and worn original rubber lines for better pedal feel and performance. StopTech lines feature an inner PTFE/Teflon liner that resists swelling and expansion under extreme pressures. The outside of the line has a abrasion-resistant PVC cover to keep dirt and debris from wedging itself in-between the stainless lines.
StopTech Brackets	StopTech BBK Brackets and Hardware StopTech calipers are mounted with hardcoat anodized 6061-T6 billet aluminum brackets. Billet aluminum brackets are model-specific for proper fitment and correct spacing. Stainless steel studs are used instead of bolts to ease caliper mounting and for additional rigidity. The hardcoat is tougher than standard anodizing.

StopTech Trophy Kits on E39 M5

MotoIQ recognized the shortfalls of stock single-piston calipers on their Project E39 M5 and turned to StopTech for a front and rear set of Trophy kits. Check out their super-detailed article by clicking here or the photo above.

StopTech BMW BBK vs. Trophy BBK vs. C43 CBK Kit

In addition to the standard Big Brake Kit, StopTech offers BMW brake kits in Trophy and C43 CBK spec. Trophy and CBK kits feature lighter calipers and rotors, a dark grey hard-anodized finish, and different rotor hardware. Trophy Sport kits are intended for street use, however, Trophy Race and CBK kits are only sold for racing/track use. There is no benefit to using these racing brakes on the street - in fact, the opposite is true. The Trophy Race and CBK kits do not have caliper dust seals as an extra layer of protection for the pistons. They will also be noisier due to the elimination of anti-rattle rotor hardware.

If you have any questions on which StopTech Brakes will work best for you, give us a call or e-mail.

Trophy kits can be built from any regular StopTech ST kit. They are offered as a lighter and more track-focused alternative.
+ Same rotor sizes as ST kits, 332-380mm
+ 20% lighter Trophy 4 or 6-piston calipers
+ Military hardcoat (dark grey color)
+ Trophy Sport has caliper dust seals
+ Trophy Sport has anti-rattle rotor hardware
+ Kits are complete with pads, stainless lines, and hardware

The C43 CBK kit was originally developed to counter the trend towards oversized brakes that just added more weight without proportionally better performance. Sometimes more is just more! The C43 kits deliver BBK-levels of performance in a smaller and lighter package.
+ 309x32mm rotors - small diameter but large thickness
+ 50% lighter C43 4-piston calipers
+ no dust seals so track only
+ Military hardcoat (dark grey color)
+ single bridge bolt instead of caliper bridge
+ C43 Sport has anti-rattle hardware
+ C43 Race uses bi-directional slot pattern
+ Fits under 17" wheels (even 16" in some cases!)
+ Kits are complete with pads, stainless lines, and hardware

	Aerorotor Sizes	Floating Hardware	Anti-Rattle Hardware	Caliper Weight	Dust Boots	Included Brake Pad Type	Stainless Brake Lines
Trophy Sport	332-380mm	X	X	~105oz	X	309 Sport	X
C43 Sport	309mm	X	X	~68oz		309 Sport	X
Trophy Race	332-380mm	X		~105oz		SR33 Race	X
C43 Race	309mm	X		~68oz		SR33 Race	X

Standard ST40 kit

Trophy ST40R kit

CBK C43 kit

StopTech Rotor Coatings - Standard vs. Zinc

The rotor rings in StopTech big brake kits are offered in slotted or cross-drilled patterns and with an anti-corrosion zinc coating or as plain cast iron. The standard cast iron rotors will show rust on parts of the brake disc, especially areas not swept by the brake pad. The zinc plating offers excellent protection from rust, especially when used with semi-metallic brake pads. StopTech coats the entire rotor in Zinc for 100% corrosion protection, even in the center and vanes. The actual friction surface is coated too but will wear off as the pads are bedded-in. The zinc coating is not effective when used with race pads as extreme temperatures will bake off the zinc, leaving exposed metal behind, as well as reducing the maximum operating temp of the pads. Also do not use brake cleaner or harsh wheel cleaners near your zinc rotors as the strength of these chemicals will ruin the zinc finish.

Standard uncoated rotor

Zinc coated rotor

StopTech Replacement Rotors

One of the key advantages of a true big brake upgrade for BMW is that the rotor friction surface can be replaced. When the rotors wear out and are below their minimum thickness you can order a new ring. You won't have to buy a new ring, hat, and hardware like on some other kits. This helps keep consumable costs down. You can even change to a new rotor style as long as the rotor size stays the same. StopTech rotor rings come with new hardware and instructions. Unbolt the hat from your old ring and transfer it to the new disc with the new hardware. The new assembled rotor is ready to be installed. Follow the pad manufacturer's instructions for bedding in the pads. Click here for replacement rotors for StopTech Big Brake Kits

StopTech R&D and Manufacturing

All StopTech products are designed and tested on site at one of their California facilities. They employ friction and materials engineers to design everything from their own brake pads to vented rotors, reinventing brake technology and earning many industry awards, TUV approvals, and ISO certifications. Their dedication to quality has earned them status as a Tier 1 supplier - a direct supplier to major automotive manufacturers like Toyota and Dodge, as well as contracts for the US military.

StopTech's Compton, California facility houses their R&D and testing offices as well as manufacturing and assembly of Big Brake Kits and stainless steel brake lines. StopTech engineers can optimize a brake system design for any vehicle application. Component and kit designs are produced in Solidworks and FEA studies are completed in Solidworks Simulation. Three in-house coordinate measuring machines are available to precisely dimension and inspect components. Testing is carried out on any of three brake dynamometers that can simulate air velocity up to 210mph and vehicles up to 24,000 pounds. They run tests for noise, friction coefficient, wear and dust characteristics, OEM and competitor evaluation, as well as simulated drive cycle testing. For on-car testing, they use Link and VBOX data acquisition systems as well as various racing programs at all levels of motorsport.

All StopTech Big Brake Kit components are manufactured and assembled in their Compton location, including final machining and balancing of rotors and pressure testing of calipers and brake lines. Not only did StopTech set out to beat the competition in the performance braking industry, their goal was to redefine it through innovative new designs and technologies to quality assurance and consumer confidence.

StopTech Facility Tour

BMW StopTech Fitment Info

Every StopTech BBK has been engineered for the specific model and chassis. Installation and clearance to the suspension and chassis is guaranteed for the models listed. However, BBK do not fit all wheel designs and sizes. To ensure proper clearance between the new brakes and your wheel, StopTech produces these fitment guides.

As a general rule, StopTech Big Brake Kits fit within these wheel diameters -

- 328mm rotor (12.9") = requires 17" wheel minimum
- 332mm rotor (13.1") = requires 17" wheel minimum
- 355mm rotor (14.0") = requires 18" wheel minimum
- 380mm rotor (15.0") = requires 19" wheel minimum

However, wheel diameter is only one factor in BBK fitment. Wheel spoke design, wheel offset, and inner barrel dimensions are just as important.

The guides below have the outline of the vehicle-specific caliper and rotor combination. To use these guides:
1. Print out the guide on card stock or thicker paper,
2. Cut the outline of the brakes,
3. Place the guide on the inside of your wheel.
Any interference with the wheel spoke will require wheel spacers. If the fitment outline touches the inside barrel of the wheel, a larger diameter wheel may be required.

BMW E36 Non-M StopTech Brakes Info

Front E36 StopTech Touring BBK
Fitment Diagram

Front E36 StopTech 332mm BBK
Fitment Diagram

Front E36 StopTech 309mm CBK
Fitment Diagram

Rear E36 StopTech 328mm BBK
Fitment Diagram

BMW E36 M3 StopTech Brakes Info

Front E36 M3 StopTech 332mm BBK
Fitment Diagram

Front E36 M3 StopTech 355mm BBK
Fitment Diagram

Front E36 M3 StopTech 309mm CBK
Fitment Diagram

Rear E36 M3 StopTech 332mm BBK
Fitment Diagram

E39 540i StopTech Brakes Info

Front E39 540i StopTech 355mm ST40 BBK
Fitment Diagram

Rear E39 540i StopTech 345mm ST22 BBK
Fitment Diagram

Rear E39 540i StopTech 355mm ST40 BBK
Fitment Diagram

E39 M5 StopTech Brakes Info

Front E39 M5 StopTech 355mm ST40 BBK
Fitment Diagram

Front E39 M5 StopTech 355mm ST60 BBK
Fitment Diagram

Rear E39 M5 StopTech 345mm ST22 BBK
Fitment Diagram

Rear E39 M5 StopTech 355mm ST40 BBK
Fitment Diagram

E46 323i/325i/328i StopTech Brakes Info

Front E46 StopTech 325mm Touring BBK
Fitment Diagram

Front E46 StopTech 332mm BBK
Fitment Diagram

Front E46 StopTech 309mm CBK
Fitment Diagram

Rear E46 StopTech 328mm BBK
Fitment Diagram

E46 330i StopTech Brakes Info

Front E46 330i StopTech 332mm BBK
Fitment Diagram

Front E46 330i StopTech 309mm CBK
Fitment Diagram

E46 M3 (non-ZCP) StopTech Brakes Info

Front E46 M3 StopTech 332mm BBK Fitment Diagram	Front E46 M3 StopTech 355mm ST40 BBK Fitment Diagram	Front E46 M3 StopTech 355mm ST60 BBK Fitment Diagram	Front E46 M3 380mm BBK Fitment Diagram
Rear E46 M3 StopTech 345mm BBK Fitment Diagram	Rear E46 M3 StopTech 355mm BBK Fitment Diagram

E46 M3 ZCP Competition Package StopTech Brakes Info

Front E46 M3 ZCP StopTech 355mm ST40 BBK
Fitment Diagram

Front E46 M3 ZCP StopTech 355mm ST60 BBK
Fitment Diagram

Front E46 M3 ZCP StopTech 380mm BBK
Fitment Diagram

Rear E46 M3 ZCP StopTech 355mm BBK
Fitment Diagram

Front E85 Z4 StopTech 332mm BBK
Fitment Diagram

E85/E86 Z4M StopTech Brakes Info

Front E85/E86 Z4M StopTech 355mm Touring BBK Fitment Diagram	Front E85/E86 Z4M StopTech 355mm ST40 BBK Fitment Diagram	Front E85/E86 Z4M StopTech 355mm ST60 BBK Fitment Diagram
Front E85/E86 Z4M StopTech 380mm BBK Fitment Diagram	Rear E85/E86 Z4M StopTech 355mm BBK Fitment Diagram

Rear E9X 335i StopTech 345mm BBK
Fitment Diagram

E9X M3 StopTech Brakes Info

Front E9X M3 StopTech 355mm BBK
Fitment Diagram

Front E9X M3 StopTech 380mm BBK
Fitment Diagram

Rear E9X M3 StopTech 355mm BBK
Fitment Diagram

Front F22 228i, F3X 328i/428i StopTech 355mm BBK Fitment Diagram	Rear F22 228i, F3X 328i/428i StopTech 345mm BBK Fitment Diagram
Front F22 228i M Sport, F3X 328i/428i M Sport StopTech 355mm BBK Fitment Diagram	Front F22 228i M Sport, F3X 328i/428i M Sport StopTech 380mm BBK Fitment Diagram	Rear F22 228i M Sport, F3X 328i/428i M Sport StopTech 345mm BBK Fitment Diagram