[WhatsADSM]

I did want to update. At first I tried to go the naca duct route. Bought the same small ones from Pegasus that the 3 series guy ran. However after removing the panels I realized there is no way that will work in a 1 series. Anywhere in that undertray and they will make contact with some other part.

So I finally had enough and just made my own. They replace the factory 135 "duct" (that just blows air at the tire cross section). So they take air from thr bumper mount up to the factory locations as well as interface to the other ductwork at the bumper. The outlet of the duct comes out in the inner wheel well (right by the front control arm to chassis mount) and is a 2.5" connection.

Then at the backing plate I designed a custom flange to channel as much air as possible to the hat (center of the rotor). I purchased those air craft spruce aluminum flanges however if you use them the vast majority of the air blows at the back of the rotor face. While that helps it's not as effective as channeling it to the center of the rotor. I use the longer route for the flexible hose. Ie. It goes back and over the lower control arm up then back up and around to connect to the heat shield flange. Doing it this way ensures that there is always low stress on the duct work from the hose from lock to lock. Also due to where my duct work goes there is no rubbing anywhere so I plan to run it all the time, street and track.

The only thing I am unsure of is the robustness of the flange at the heatsheild. I wanted to instrument the backing plate and take some measurements but figured it's just easier to try it and see how it holds up. My suspicion is it will probably be okay, the material is polycarbonate which has a service temperature around 250*F. The backing plate doesn't get nearly as hot as the rotor and of course the entire purpose of a brake duct is to have cool air flowing through it. We will see as this weekend I have a 2 days of track time









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Edit: looks like Mernardi did manage to get the naca ducts to work. Looks like you have to actually span the underbody that and the inspection plate. In any case good work I couldn't manage to get it to work.