Saturday, March 14, 2020

[Focus] Back to Laguna

[note: this post, like an air-cooled 911, is back-dated to when these events occurred]  

Tame Impala show was called off due to Covid-19, but the track day continued as scheduled.

Things got off to a soggy start with a wet track and some drizzling for the first session and change. I started off slowly, taking the beginning of the session to bed my new pads (at the back of the grid of course) and feeling out the new tires in the wet. That session was cut short when I was meatballed for blowing sound. 93.4 dB versus the limit of 90dB. This was a surprise, because the last two days I did here were 92dB and 90dB and I had no issues. I didn't blow sound again for the rest of the day so I think it was probably humid/dense air combined with an inopportune exhaust pop close to the sound booth.

Pace increased as things dried up by the end of session 2. Traffic was fairly thick so it wasn't until session 3 that I ran a complete session at full pace. The new brake setup felt strong, the tires as well, but it was with dismay that I noticed the brake pedal grow long after 4-5 laps. In that dry, fast third session I cooked my brakes yet again. The DBA discs come with color-changing paint witness marks and all three of mine had changed, indicating rotor temps at or beyond 630C. The wheel rims were uncomfortably hot to the touch for quite a while after the end of the session. At least my brake pads still existed, more than I can say for the Mountune UK parts last time...

With a couple sessions left on the day I figured I would test the theory that the brake vectoring is taxing the system beyond my braking inputs. Having run the first three sessions of the day in Sport, I ran the next session in Sport with ESC disabled. I was anxious about turning off the aids because... well, then you're on the hook for your driving. I was ready for a slice of humble pie, to see where the magic Ford traction system had been pulling the strings in the background, cleaning up my mess. So I went out gingerly at first, increasing pace, until I was back to driving essentially the exact same lines in the exact same way. I noticed a bit more controllable rotation out of the slower corners (out of 2 and 11) but otherwise I was running just as fast with just the same grip. Little to no perceived difference with ESC off! The brakes seemed to go an extra lap or two before fading away but even fully cooled the pedal had become long. I'd cooked the fluid for good early in the day so a direct comparison was not going to be possible. Bummer.

In the sixth and final session of the day I tried Track mode (ESC off by default) but dropped the dampers back to the less stiff setting. Again I didn't feel much of a difference. In these later sessions I ran somewhere in the 1:51s, which is faster than my previous outings where I did 1:53s. This may be due to the new tires, the brakes, or my developing experience on this track. It is interesting to note that even though brake feel (and affiliated confidence) deteriorate through the sessions, my times are pretty constant throughout. It is worth noting that the Ventus R-S4s also started to feel a bit greasy by the last 2-3 laps of the sessions, still stable and with good grip but not as fresh as the start of each session.

So now I'm looking for the next step to help these brakes. I see, I guess, four options.

  1. Replace the factory brake ducting. Found the AAF kit today, $400 and replaces the factory system. I emailed them to see if I can get a copy of the instructions to see how it all goes together.
  1. Essex/AP Racing complete front brake kit. $2725 with pads. "Nuclear option." Expensive and might put me in a weird spot in terms of how to use it on the street. Requires some grinding of the RS suspension hub. Instructions explicitly say not to use ducting. Might not fit with my wheels. Not cool Nitrous Blue like OE.
  1. Two-piece rotors from Girodisc. $900. 1/3 the cost of the complete AP system but doesn't seem like a particularly promising fix on its own.
  1. Racing Brake ceramic discs (calipers too?). $7200. Too expensive.

I will have to spend some time thinking about the situation. Option 4 isn't on the table, and between the other three there are dependencies that make it challenging. The ducting and two-piece rotors, if they don't solve my problems, will become paperweights when I buy the complete Essex/AP kit because they are not compatible. It's not fun to spend a ton of money (option #2) but it's mighty tempting to just put the issue to bed and stop worrying about it. But what am I really gaining? This is a fun daily car that I like to take to the track, but I'm not building a race car. Is 3-4 laps of faded brakes at the end of a session worth the cost and complication of these added parts? Based on my lap times it doesn't really even seem to impact my pace.

Enough of that, here's something different. There must be a media day coming up because Porsche had a whole posse of brand new 992 Turbos tucked in a corner of the paddock behind a fence. A few GT2RS to boot. Cool to see Porsche's "S GO" license plates in the flesh.

Blue for me, please.

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