I've searched, and although I have found information on fabricating brake ducting for cooling the front brakes, I have not seen anyone address the idea of supplementing the ducting with high cfm 12v fans directed at the calipers/pads to improve cooling in hard braking applications.
These are thumbnails, with large pictures not suitable for 56k, of the left and right sides. The SMIC has been removed and replaced with an FMIC, and the fog lights have been removed.
Leaving a nice space for cooling ducts towards the front brakes. Which has been done before, however, my question is, would the additional of a pair of high cfm 12v fans in the ducting produce enough additional airflow to justify the (minimal) additional weight of the fans/relay/ducts and so on?
When the car is being driven hard, there's naturally a certain amount of turbulent air forced up under the wheelwell, which cools the brakes. Although I can't picture a fan of that size (5 inch diameter, estimated) being able to flow enough air to overcome the air currents tumbling around under the wheel well, enough to provide any significant additional cooling, when the car stops, the fan would hypothetically provide additional airflow to cool the hot brakes down significantly faster.
Although it wouldn't have that much effect while actually driving hard, the benefit would come from the shorter period of brake cooldown after the car is stopped, allowing overheated brakes to return to an optimal temperature range more quickly. So on that next run, the brakes are starting out cooler, although of course not completely cold, which is a good thing.
I don't see a lot of benefit for daily driving, but for autocross or other short duration applications where a shortened brake cooldown period would desirable, I'm thinking brake cooling ducts fitted with lightweight high flow 12v fans would be a worthwhile modification. Of course the front dust shield would need to be cut through for a vent, directed at the brakes themselves.
You can see in these photos that my dust shields are pretty ratty anyway, and need replacing. Is it worthwhile to add electric fans in that space, mounted as far rearward, as close to the brakes as possible? I could easily tie them into the existing set of toggle switches on the center console, but a more complete solution would be to use a temperature activated switch to control the fans, as needed.
