|The outside shoulder of the left front tire after three sessions.|
|The shoulder on the right side tire shows much less wear.|
|The left front tire takes a beating on the shoulder at Willow Springs. After the morning sessions, I rotated the Nitto NT01s side-to-side to even out the wear. The tires performed great over the course of the day with consistent and high levels of grip. Again, the tires proved to be easy to drive at the limit and progressive in their breakaway as they had at the auto-x.|
So let’s get back to the brake ducts. I did one session with the brake duct installed on only one side of the car. I came in hot to the pits after running about 5 laps, hopped out of the car and took measurements as quickly as I could. The un-ducted side measured 400F while the ducted side measured only 280F. I would say the ducts did a pretty decent job!
|I used a Raytek MT6 Infrared Thermometer to take the brake rotor readings. I’m pretty sure it’s just a rebadged Fluke 62, but the Raytek was on sale for $20 less; they both have the same MSRP. They both have a temperature range of -20F to 932F with an accuracy of 1%. If you remember from my Fluke Thermal Imager article about taking readings, IR devices don’t like the shiny surfaces so I had to target the rusty surfaces due to their higher emissivity. Using the Raytek, I scanned across the edge of the rotor and used the highest reading. The shiny rotor surface gave off a reading well over 100F cooler than the rusty edge when the brakes were hot.|
With both front brake ducts installed, I compared the front rotor temperatures to the rear rotor temperatures. After one cool-down lap and pulling straight into the pits, the front rotors were down to around 240F while the rears were at 440F! Back when I tested the Fluke Thermal Imager with no front brake ducts, the temperatures of the front and rear rotors after a cool down cycle were 231F and 337F respectively for only about a 106F degree temperature difference. With the brake ducts installed at the track, the front brakes cooled much faster resulting in the 200F difference. The very hot rear rotors are the reason why you don’t set your parking brake when you come off the track. For another reference regarding front to rear brake temperatures, Project 370Z measured about 250F in the front and 200F in the rear after sitting in the pits for a bit.
Here are the shots from the Fluke Thermal Imager after a cool-down without brake ducts comparing front and rear brake temperatures.