Ingenious Toyota GR86 and Subaru BRZ Bolt-Ons Transform Control Arms Into Brake Cooling Systems

      A'PEXi, edited by the author

      Subscribe to The Drive’s daily newsletter

      Check out this cool modification that can be added to your Toyota GR86, Subaru BRZ, or Scion FR-S. It’s an air duct that attaches to the lower control arms, directing fast-moving air toward the front discs and calipers for cooling. This appears to be an excellent aftermarket option for extending the lifespan of Toyobaru brakes used on the track without the need to cut anything.

      I've noticed people crafting similar setups from dryer hoses, but I haven’t come across a well-made, bolt-on duct specifically designed to attach to a car's control arm like A’PEXi’s N1 Brake Duct.

      Managing brake heat is an unexciting yet essential element of car tuning. Flushing out your stock brake fluid for a high-performance alternative is one of the first modifications you should make to any sports car and is essential if you're heading to a track. The next step would be to install stainless lines (to prevent expansion) and, naturally, larger brakes. Alternatively, since large brake kits are often costly, a system like this might be a good option.

      A’PEXi

      One aspect I appreciate about A’PEXi’s brake shroud is that, if it is effective, it offers benefits with minimal downsides—it likely has little weight and won’t be noticeable from outside the car. However, that bit of additional airflow could significantly help in cooling the brakes as you accelerate down a straight.

      A’PEXi is a well-established brand in the realm of Japanese car tuning and racing; I’ve used its exhaust systems on a few of my own vehicles. I reached out to the company’s sales team to learn more about the development of the brake duct and its expected effectiveness. While I didn't receive a “with vs. without” heat graph, Takuya TK Akiyama provided some intriguing insights into the product's development. Here’s what he shared:

      “This product was created through our direct participation in the GR86/BRZ Cup in Japan, where professional drivers Takuto Iguchi and Rintaro Kubo compete with their Tokyo Subaru BRZ and Chiba Subaru BRZ, both outfitted with various A’PEXi components. These include the A’PEXi N1-X Exhaust System, Exhaust Manifold with Super Catalyzer Kit, N1-X Dampers (coilovers), and reinforced Carbon Strut Tower Bar and Ti Toe Cowl Brace (V-Bar).

      Working within the parameters of the cup series regulations, we looked for solutions that could provide real performance improvements without significant modifications. Drawing from our experience with past JGTC (Super GT) race vehicles, where brake cooling duct systems were essential for maintaining optimal braking performance under extreme conditions, we developed a street-friendly, motorsport-inspired solution.

      Unlike conventional tubing-style ducting seen on cars like Porsches, our N1 Brake Air Shroud Kit features a bolt-on, OE+ design that doesn’t require cutting or modifying factory panels, bumpers, or suspension parts. The system includes a lower duct that channels airflow generated by the vehicle’s motion to an upper duct, efficiently guiding cool air toward the brake rotors.

      While the effectiveness will depend on the brake compound and rotor type, our data indicates noticeable improvements in braking stability, reduced braking distances, and enhanced trail braking ability, all of which assist in achieving quicker cornering transitions. This development reflects our motorsport knowledge from JGTC, Super Taikyu, and D1GP, now adapted for street and track enthusiasts.”

      A’PEXi offers its N1 brake duct kits for $450 on its U.S. website, compatible with all Toyobarus dating back to the 2013 Scion FR-S. You could potentially create a similar setup yourself for less, but I would prefer to use the professionally designed option. Akiyama also noted that the duct is available for the GR Yaris, with versions for other vehicles supported by A’PEXi expected soon.

      Have a tip? Send us a note at [email protected].