Here's a up date to my brake duct install. I just did a Track Daze event at VIR June 9th and 10th.
This was my 2nd time running HPDE1. My brake rotor temps on my 4th run with a outside air temp of 93F were front rotors 420F and the rear rotors 395. I'm guessing I was running 8 or 9/10. FYI My hottest ngine oil temp was almost 290F and 19PSIG oil pressure at idle when I got back to the pits.
I don't have a good base line temp for rotor temps at VIR except for 350F on front rotors with a outside air temp of 60F. This was my first time at VIR running group 1 at 6/10 I'm guessing.
At Summit point main in April with a outside air temp of 75F the front rotors were 490F and the rears 440F running 8/10 or 9/10 I'm guessing.
Fyi I had new brake pads on all 4 corners and stock rotors still and I'm running my car harder each time I go out for a new HPDE1 event .
Overall I think the brake duct system helped.