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StopTech Front 4 Piston ST-40 Big Brake Kit 2015-2021 WRX

SKU 83.843.4700.61
Original price $3,418.92 - Original price $4,409.91
Original price
$3,418.92 - $4,409.91
Current price $3,418.92
Select Caliper Color: Silver
Select Rotor Version: Slotted

North America’s leading manufacturer and supplier of aftermarket brake and chassis components, has introduced front and rear StopTech® Big Brake Kits for the 2015 Subaru WRX with stiffer calipers, larger rotors, higher friction pads, stainless steel lines and application-specific mounting brackets and hardware. StopTech High Performance Big Brake Kits (BBK) offer significantly improved braking performance, feel and modulation over stock systems and are available in a variety of caliper color/rotor finish options.

In extensive track testing with professional drivers, the front-only and 4-wheel StopTech BBKs for the Subaru WRX ran significantly cooler than the stock components. Drivers experienced less fade, better pedal feel and easier modulation. They also noted improved handling and steering thanks to front brake components that weigh approximately 9 pounds less per corner than stock.

The FRONT StopTech Big Brake Kits for the 2015 Subaru WRX include a pair of drilled or slotted 355 x 32 mm StopTech 2-piece AeroRotors and four-piston StopTech ST-40 calipers, as well as mounting brackets, stainless steel lines and StopTech Street Performance brake pads.

The REAR StopTech Big Brake Kits for the 2015 Subaru WRX include a pair of drilled or slotted 345 x 28 mm StopTech 2-piece AeroRotors and two-piston StopTech ST-22 calipers, as well as mounting brackets, stainless steel lines and StopTech Street Performance brake pads.


  • StopTech ST Calipers - stiffer, forged, differential-bore calipers with a patented bolt-in bridge that eases pad changes while increasing caliper stiffness
  • StopTech 2-piece AeroRotors - pre-assembled, directional iron rotor rings with patented AeroVane fin design and aluminum AeroHats for optimal cooling
  • StopTech Street Performance Brake Pads – Kevlar-like, para-aramid composite pads for aggressive street driving and occasional track day or autocross use
  • StopTech Stainless Steel Brake Lines - braided stainless steel shielded Teflon-like lines for less system compliance and greater durability
  • Mounting Brackets & Hardware – hard-anodized, billet aluminum mounting brackets with stainless steel studs and all of the necessary hardware for easy installation

With stiffer components and patented heat management technology, all StopTech High Performance Brake Kits provide shorter stopping distances, better brake modulation, firmer pedal feel and less brake fade for stronger, more reliable performance on and off the track.


For ultimate track racing performance StopTech offers Trophy Race Big Brake Kits, with naturally anodized lightweight components designed to survive the rigors of racing. Trophy Kits feature fully forged, lightweight STR calipers, 2-piece AeroRotors®, braided stainless steel brake lines, mounting brackets and hardware. The MAX Float hardware allows for the greatest amount of float between the hat and rotor. These Trophy Race Kits are used on many of the top competitors in the SCCA Pro Pirelli World Challenge Championship as well as in Grand-Am and other race series.

Ultimate street performance is obtained with a StopTech® Trophy Sport Big Brake Kit. The Trophy Sport Big Brake Kits are designed for street driven production vehicles and use the same STR calipers, AeroRotors® and AeroHats® as the Trophy Race Big Brake Kits, but add silicone dust boots to extend service intervals and anti-rattle rotor mounting hardware for quieter street operation. Trophy Sport Kits also include StopTech® Street Performance brake pads for high performance street and occasional track use. They are the ultimate street braking system.