One of my instructors had a 991 C2S with Michelin Pilot Sport Cup 2s (R-compound tires, or semi-slicks). He claimed he could easily do 2:08s, which is about on pace with a 997.1 GT3 RS. I'm sure he was also running track brake pads, since R-compounds generate more heat than street tires. If I went this route, then my upgrade path would look like:
- Brake pads
- 19" rims
- Michelin Pilot Sport Cup 2s
The unfortunate thing about the Pilot Sport Cup 2s is that Michelin does not make them for my 18" rims (235/40 front, 265/40 rear), but they are available for the 19" rims (235/40 front, 295 or 305/35 rear). Then that's at least $1k for the rims, and $2k for a set of tires after tax. I also looked into Pirelli's P-Zero Trofeo Rs, which are available for my 18" rims and cost only $1.4k a set after tax. As for functional differences between the two tires, the Michelins offer less peak grip at 1.6g vs 1.8g, but the transition to sliding is more gradual at the limit than the Trofeo Rs. As for practical considerations, the Michelin has more treadwear, and has a reasonably long life expectancy. It is classified in a lower penalty group in autocross car classification.
I had one last track day this season with Hooked on Driving (HoD) at Thunderhill again. I improved my exit speeds on average, and greatly improved my entry speeds on T10 and T11. Overall, I was able to cut my best time by 6 seconds down to 2:21.xx. A huge difference between the Porsche Club (PCA) and HoD is that HoD puts turn-in and apex landmark cones on the track, while PCA doesn't. I agree with PCA that cones should not be present so that drivers develop their own references instead of relying on a temporary object that can get knocked out of position. However, they're really helpful and reinforced several of the turn-in points for me.
Carrying more speed through turns means that I'm falling out of my seat more and more and devote more energy to bracing myself. In particular, my left leg was super sore by the end of the day from standing on the dead pedal in turns. I've been researching various aftermarket race seats, specifically the halo-style seats (wraparound head support). Fitment is done mostly by hip width, so the driver is held securely in place, even with a standard seatbelt. A decent seat is also only $1k, and can be swapped into another car if I choose to run another vehicle.
I think I'll stick with the 3-mile Thunderhill course for next season, and explore other local tracks for the 2017 season, and at the earliest, the end of 2016 season. At my HoD day, I ran with their B group (intermediate) for two sessions with my instructor, and felt pretty comfortable. I'm running at a mid-pack or slightly below median pace. With a bit more practice, I should be high B by the end of 2016, perhaps low C. For now, I'm hesitant about point-by passing nearly everywhere because it sounds scary, and am afraid that other people in the run group will dislike my conservative point-bys.
As for brake pads, I don't see any reason to upgrade. The car has 0.5g of deceleration during hard braking, and I haven't had any heat issues yet. Given that I won't upgrade the engine power anytime soon (car is plenty fast), I won't need more braking force to compensate. Same for rotors -- larger rotors in theory can better dissipate heat due to more surface area, and lots of heat may cause rotor warping, which also hasn't happened yet.
I will keep the suspension stock as well for the upcoming season. When I get better at discerning different adjustments, I'll consider adding a GT3 sway bar and adjusting camber/toe.
That's all for now. Here's to a safe and fun 2017 season!