Some Geniuses Are Using $70 Worth Of Porsche GT3 Ducts For Dirt Cheap Brake Cooling On All Sorts Of Cars

There’s no greater thrill than driving on a closed course, being able to properly experience speed without worrying about breaking the law or not having enough runoff. Track days are some of the most fun you can have in a car, but they are hard on brakes. However, before you go out and splash the cash on a big brake kit, you might want to look into a pair of shockingly inexpensive Porsche 911 GT3 parts.

With a conventional braking system, you’re turning kinetic energy into heat every time you hit the brake pedal. Unsurprisingly, the hard braking zones on racetracks generate tons of heat, and brake discs can only absorb so much without adequate cooling. Get your brakes too hot and you can boil the fluid or glaze the brake pads, reducing the effectiveness of your brakes. When you’re travelling at triple-digit speeds down a straightaway on a closed course, you’re gonna want some stopping power. These days, most discs are ventilated, meaning they have air channels inside of them that increase their effective cooling surface area, but how well those channels work depends a lot on how air’s guided to them.

Or, you could just order Porsche part numbers 99734148392 and 99734148492, the left and right brake ducts for a 2007 to 2008 Porsche 911 GT3. While this might sound hideously expensive, you’d likely be surprised at just how inexpensive these pieces are. A set of left and right ducts from FCP Euro will run you $67.26. That’s less than $70 for a pair of genuine Porsche brake ducts.

Just like its 996 predecessor, the 997 Porsche 911 used MacPherson strut front suspension with an unusual lower control arm setup. The main control arm ran perpendicular to the direction of travel, while a trailing arm of sorts ran diagonally from the tub to a mounting point on the lower control arm. The GT3 brake ducts are just big plastic scoops that clip onto these trailing arms and with a little bit of modification, they can likely be made to fit your independent front suspension too.

Indeed, the prevalent method of making these things fit is to snip or Dremel off what needs to be ditched, then simply zip tie them to the leading edges of your lower control arms, making sure they’re aimed to send air to your hubs. For reference, here’s a set of cut-up GT3 brake ducts on a Subaru BRZ, as posted to the FT86 subreddit. Although it might seem a little janky at first glance, flimsy little clips were good enough for Porsche so cable ties should be good enough for everyone else. Plus, these ducts are a huge upgrade if your car didn’t come from the factory with any brake ducting.

Do they still work when hacked up? You bet your bottom dollar they do. One GR86 owner by the YouTube username Track and Build fitted a GT3 brake duct to one front corner of their car and left the other alone, then went out to get the discs hot. The result? While the side without any brake cooling duct measured 156.5 degrees Celsius, the side with the duct clocked in at 118.9 degrees Celsius. That’s a temperature reduction of 37.6 degrees Celsius, or 24 percent. Can that be the difference between happy brakes and unhappy brakes? Absolutely.

Oh, and because these ducts are sort of trim-to-fit, you can put them on far more cars than just Porsches and Toyobaru twins. One poster on M3post.com fitted a set of these ducts to their E9x M3, the V8-powered one. As the forum member wrote, “Had to do some cutting as the original piece was too long and slightly too tall. Had to trim at both ends, as well as make cutouts so the duct wouldn’t foul against the lower arm knuckle and sway bar link. Then tied it all together with some cable tie.” Easy-peasy. As for whether they worked, the poster followed up with:

Trackday over and the ducts performed admirably! Stayed attached after several 200+kph runs down the front straight of Sepang F1 Circuit. They also helped a lot in preventing fade. I usually start to experience brake fade after the 3rd session, but I ran 5 sessions today and no fade. Would love to hear from the other trackies if they have pyro data on these ducts.

That’s a huge win for such little spend. The first rule of trackdays is to be safe, and the better your brakes are at staying in their window of optimal operating temperature, the safer you’ll be out on track.

Actually, another good testimonial about how effective these brake cooling ducts are is how people are installing them on pricier cars. Yep, that’s a GT3 duct on a Lotus Emira. User kitkat on emiraforum.com has even provided a handy template for owners looking for extra brake cooling on their boutique British sports cars.

Sure, these ducts used to be even cheaper, but they’re still a downright sensibly-priced way of improving brake cooling on all sorts of cars. So, if you find yourself getting addicted to the rush of performance driving, why not spend less than $70 on a pair of GT3 brake ducts? If they’re the difference between brake fade and no brake fade, they’ll quickly pay for themselves in added seat time alone.

Top graphic images: FCP Euro; YouTube/Track and Build; Subaru