M4 brake cooling

[Flying Low]

I tried this setup on my M4 at Laguna Seca last Friday. Air scoop is 3" X 9" with mounting flange cut off. Hose is 2.5" in diameter but squeezed down to about 2" high and 3" wide for more clearance under the anti-roll bar and then back until the hose has to change direction sharply, where I let it be 2.5 inches round again all the way to the disc backing plate. The front and rear of the car are dropped only about 1/2" and the air inlets have 3.5" clearance to the ground. But at the anti-roll bar and behind, there is only about 3" clearance to ground. No speed bumps allowed!

In the 3rd picture you see a plastic piece that has one rivet mounting it to the aluminum rail on both sides of the car. This piece might help protect the under side of the car. I took this off to make room for the 3X9 air collector.

The 4th, 5th, and 6th pictures show how I modified the front corner plastic pieces just under the bumper cover. The 6th picture shows how I notched the 3X9 outer wall of the collector so that the collector is supported by the lower edge of the bumper cover. Also in this picture you can see the big bolt (13mm head) and washer that already exists but was removed and replaced to hold the collector in place. The bolt and the notch hold the collect firmly in place. It did take some trial and error to get the notch just right.

The 2 1/2 " hose was built up with tape where it goes to the inside of the 3" outlet of the collector. There are various existing mounting places along the bottom of the engine shield to hold the squished down hose as high up as possible and keep it there.

The 7th picture shows the 2 1/2 " aluminum flange fitting from Aircraft Spruce that is held in place by 5 pop rivets. You want to cut out for the entire circumference. I put this flange in close to the center as possible so the the rotor vanes can pick up the air stream.

But the stock M4 rotors have an open hat design, so some or most of this air might actually blow through the hat and not get picked up by the rotor internal vanes. My next rotors will have a closed hat design.

I had my dust seals replaced and new PFC11 pads right before I tried this setup at Laguna Seca which is known to be hard on brakes. I run a 1:43 time now and still improving but at this level and with the cooling, the dust seals were destroyed after one day. I took some rotor and outside caliper temperatures with temp gun after about 2 minutes of cool down on track and five minutes driving around paddock. Got about 550F on rotor and 350F at outside caliper. But the brakes never felt like they were fading. I'm hoping for better temperatures with a closed hat design.

[Speed District]

wow that is badass. Would love to have this on my M4. I ran Laguna for my first time a couple months ago in my M4 with completely stock brakes and michelin PSS. I ran a 1:45 but my brakes were absolutely toast by the end of the event and had to be replaced lol