Just back from day & 1/2 at Road America with my brake duct kit. First, essentially no rubbing! Only at max lock does it just rub a bit and I'm almost never there (only rarely in a parking lot). The adjustment I did to the tubing per Cantrell recommendation was to squeeze the tubing into an oval where it crosses over the lower control arm and this give a bit more clearance.
As to performance. Ran the first session with ducts blocked off to bed in the pads, and the track was moist with a threat of rain. Then took off covers and ran the rest of the event with the ducts open. Brakes were rock solid throughout every session. Heat build up was lower too. Coming in from the track the rear brakes would be pretty hot, with the usual clicking noise and a lot of heat coming off the rotors. Fronts were hot too, but much cooler by feel and no clicking noises. Overall, very effective and worthwhile addition. Can't tell about pad wear yet but would expect it to be reduced too.
Last edited by VictorH; 08-15-2012 at 06:55 PM.