The BimmerWorld View: StopTech C43/C42 brake kits are focused on club racing sprint, medium endurance, and dedicated track cars that need a race-level braking package but are also weight sensitive and don't want the negative side effects from too-large brakes. The trend in brake kits has been "bigger is better" and that's just not the case all the time. Sometimes bigger brakes just add more weight without any appreciable gains in performance. The larger kits also suffer pad knockback and force you into a larger tire/wheel for clearance. It's time to re-focus braking performance on what counts!StopTech C42 Race for E36 M3 features -
- Super-focused on light weight and performance
- 50% lighter than ST40 caliper
- 50% better cooling airflow than Aerorotors
- Smaller diameter rotor for lower weight and MOI with less pad knockback
- Super-thick rotor does not give up any cooling capacity
- Fits under 17" wheels
- Race kit: Race pads, bi-directional slot pattern, no anti-rattle hardware
The C42 caliper is a 4-piston layout, forged from aluminum, sized and machined to minimize weight. The C42 is
50% lighter than a ST40 caliper and even lighter than the Trophy kit! Stainless steel piston noses and anti-knockback springs are optional. A single bridge bolt saves weight and reduces pad change times. C42 calipers do not include dust boots so street use should be minimized.
Rotors are 2-piece 298x20.6mm with a new bi-directional slot pattern. The diameter is kept small to reduce MOI (Moment of Inertia) and prevent the pad knockback so pervasive in oversized Big Brake Kits. The thickness contains enough cooling capacity for these cars. The rotors also use StopTech's pillar vane construction that is lighter and cools better than traditional vane designs. C43/C42 rotors
flow 50% better than usual StopTech Aerorotors! Pillar design uses aerodynamically-shaped posts inside the rotor that have more surface area for better cooling. Race CBK kits do not come with anti-rattle hardware but do have a floating system that further reduces pad knockback. No parking brake is permitted with this kit.
StopTech's C43/C42 caliper is the result of years of R&D in road racing and short-track circle racing, which is a merciless proving ground for brakes. With R&D input and testing from BimmerWorld, StopTech has made this caliper design available for limited BMW applications through BimmerWorld. BMW C42 kits feature all of the great advantages of a regular StopTech Big Brake Kit: the Balanced Brake Upgrade(R) approach that optimizes brake distribution to improve traction at all four corners, patented rotor cooling vanes for longer pad life and less fade, and the stiffest caliper designs in the industry.
| Aerorotor Sizes | Floating Hardware | Anti-Rattle Hardware | Caliper Weight | Dust Boots | Included Brake Pad Type | Stainless Brake Lines |
| Trophy Race | 332mm | X |
| ~105oz |
| SR33 Race | X |
| CBK Race | 298mm | X |
| ~68oz | | SR33 Race | X |
C42 calipers do not use dust boots on the caliper pistons and are only sold for racing or exclusive track activity only. Caliper dust boots play a key role in preventing debris from damaging the inner piston seals and causing a very dangerous loss in brake pressure. As with any racing braking system, periodic rebuilds and regular fluid changes using an appropriate fluid are strongly advised.
C42 calipers are only available in dark-grey military-spec hardcoat.
CBK kit comes with StopTech pads.
Best Price Guarantee!BimmerWorld StopTech pricing will not be beat! If you found a lower published price elsewhere, call or email us and we will meet it or beat it!
BMW Fitments:3 SeriesE36 (95-99) > M3
