"Mr. Toad" at Laguna Seca (23 February 2022)"Mr. Toad" at Laguna Seca (23 February 2022)
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Although I have the experience to run in the Advanced group, I find that Northern California track days tend to have a lot of really fast cars and there's a point where experience cannot make up for a horesepower deficit. For that reason, I generally choose the Intermediate group. Curiously, in car-crazy Southern California, I find the Advanced group to be a better fit.
Best lap of the day
(1:52.018)
After evading the Porsche pylons I gradually improved my lap time, culminting in a best-time on my last lap of the day. A peculiar phenomenon is that laps which feel really good turn out to be only ok, and my best laps often don't stand out in the moment. This was one of those laps: it felt good at the time, but I didn't know until looking at the data that it was my best of the day.
I was nevertheless disappointed that I was a half-second slower than my best lap at Laguna Seca.
My top speed on this best lap was "only" 111.9 mph on the front straight. Curiously, that was significantly off my best of the day: I often saw 113 mph and on one lap saw 113.4 mph, my fastest speed at Laguna Seca. I was slower on turn 2 on this best lap. Combining a fast turn 11 and late braking and a fast attack for turn 2 should help get me below 1:50.
The following table summarizes tire pressures throughout the day, in PSI, along with front-brake temperatures, as measured with a pyrometer after each session. The pyrometer I used just reads "Hi" for anything above about 500°F so for those cases I only know that the brakes got really, really hot. That also caused some brake-pad warping. (I've since purchased a new pyrometer that can measure up to 1022°F.)
rotor caliper Description Time Ambient LF RF RR LR LF RF LF RF morning 0903 53°F 28 28 30 30 after session 1 0944 45°F 35.5 36 33 33 after session 2 1044 47°F 36.5 36 34 33 500+°F 500+°F 382°F 376°F after session 3 1142 50°F 36 36 34 33 500+°F 500+°F 389°F 398°F before session 4 1314 52°F 30 29 30.5 31 after session 4 1345 51°F 35 35.5 33.5 33 after session 5 1443 52°F 36 36 34 33 500+°F 500+°F 382°F 372°F after session 6 1543 51°F 36 36 33 32 500+°F 500+°F 383°F 384°F after session 7 1644 49°F 36 35.5 33 32 472°F 500+°F 362°F 394°F
I hadn't tweaked pressures in my track tires since my previous track day but I rotated tires front-to-back which led to low front-tire pressures. I decided to live with that on the assumption that heat would bring them up something reasonable, which worked out well. Pressures afer the lunch break were again somewhat low but they came up to what I wanted afer a few laps without undue rolling.
My mechanic came out scratching his head: never before had he seen a brake
pad with its backing plate warped due to heat. The warping led to uneven
wear of the pad material, as seen at right on the pads from the right front
brake which was worse than the left. (The worst distortion was on the inside
pad.) There was a decent amount of pad left so I'll use them for the first
half of my next track day, planning to change them during the lunch break.
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Copyright © 2022 Karl L. Swartz. All rights reserved. |
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