Got back on the track this past weekend, w/
The Driver's Edge at
MSR-Houston. 8 sessions over two days, CW direction (which I haven't done in a long time, but it's the direction I went my first few times at this track ages ago).
I didn't capture any data/video this time, partly because as time goes on I'm just getting lazier about caring about that, and partly because I'm starting to lose interest in lap times as a metric as I get better at feeling the car and just knowing how much I'm improving (or not) based on the feel of the car and how my car control skills are developing.... but mostly because my Android phone w/ Cyanogen is a buggy POS and I couldn't get my datalogging app to sync w/ up reliably with my GPS and OBD-II units
.
It was a really good weekend overall.
Temps:
Really hot conditions, and I'm pushing the car even harder than I have in the past. The 19-row oil cooler really started showing its limitations, as I was hitting 260F at the end of almost every session (250 on a couple of cooler sessions with some clouds rolling in). Coolant would also crawl up 2-3 dots from its normal position, and I was getting a bit of coolant overflow (could see the evaporated splash marks around the front area of the engine). I've got time to deal with that before next spring; my next weekend is in November and ambient temps will have dropped back down nicely by then.
Brakes:
The new rotors held up ok through the weekend (as in, I didn't have to panic and/or cancel any runs), but I can already see a perfect pattern of uneven spots in the transfer layer down the centerline of the pad width in the front, and I could feel the first real hints of vibration creeping in by the end of the weekend. I'm not sure if that pattern develops naturally as a self-reinforcing regular phenomena once a few slight high-spots develop (like the suspension ripples that develop in a dirt driveway), or if it's when I hit ABS those pulses set up the start of the pattern (which is pretty rare now, I only popped into it briefly about 3 times all weekend, and quickly modulated to get rid of it).
I'm sure I'm dumping a bit more heat into my front brakes than I should be if I were a better driver. I still often start my braking zone a bit early (usually out of fear because I'm carrying more speed than I'm used to or whatever), and then realize the error as the car slows and just kinda drag it out a bit. I should at least just finish early when I start early and then get back on throttle early, or something.
Regardless, I need to make another change in pads and/or rotors to get past this problem. Even with front ducts, they're just not holding up to the abuse, and I can't keep tossing out rotors after a weekend or two. I think my next experiment will probably be just to switch pads, since I've never moved off of Carbotech during all these rotor-destruction events. I informally polled all the 350/370 guys I found at the track and got a list of pads that are working for others to pick from: Hawk DTC-60, PFC (not sure which, and they may not support my caliper shape yet?), Ferodo DS2500, Hawk Blue (with the caveat that they wear down rotors really fast, but hell they can't wear them down faster than I'm hot-spot destroying them now), and Stoptech (the guy is using their high-end street compound and said it lasted fine in HPDE). Any other input or recommendations welcome. If I can't clean up these front rotors by trying to remove deposits, I may try yet another rotor brand for fun too, maybe DBA 1-piece, or see if Wilwood makes a good 1-piece for this car. Rears are always fine, I'll probably just leave the existing rotors + XP8 there until something wears out.
Other car setup junk:
The need for some newer and stiffer coilovers is becoming more and more obvious every time I go out. Car's just too soft, and the total travel height from the braking dive back up to on-throttle is just really tall. I guess the upside is it's helping teach me to ease off the brake pedal at the right rate to counteract most of the heavy rebound, but it's still annoying and I'd probably be doing even better at brake->throttle transitions if I had more stiffness and shorter total travel. It's not so much an issue on side-to-side rolls because my heavy swaybars hold the car pretty stiffly in that direction, although in some transitions I do find myself wishing the car would finish the side-to-side weight shift process a little faster.
Also, with my skills improving this weekend I got into fuel starve a lot quicker than I expected. Only 2 dots were blacked out on the gauge (well, it switched to 3 dots blacked just *after* the event), and it was on a corner I had never had a fuel starve problem on before because I was never very good at it before
. It didn't hit until halfway down the straight after a series of rights that pushes a lot of straight-sideways G-force out to the left, and it was just a brief cut and it came right back as I eased off the throttle pedal. I should have Phunk's new system in place before November though.
Me:
Things are going well, I think. The more I learn, the more I realize I still have a ton to learn. Instructor feedback is positive, they say I'm about where they expect me to be for the track days I've been to, and that I'm approaching a new plateau of skill that I'll probably bump onto in a very obvious way in the next weekend or two, which is probably when they'll shift me up another rungroup. Right now they've got me in the Blue group (which is their 2nd-level and the one people seem to pile up in for the longest time, it's always a big field) running alternating solo/instructor sessions there (you start out all-instructor in Blue, so the half-solo part is sort of a halfway-point to the next level).
I'm getting much better at car control in corners, and letting the rear drift properly while unwinding the steering in sync and being able to accelerate a lot harder and earlier than before without feeling a ton of oversteer risk like I did in the past. Similar stuff going on in long constant-radius corners: learning to just let that back end slip the whole time and manage it with the steering/throttle input and rock around there at much higher speeds than I was doing before when I was trying to keep it from slipping
. I still really need to work on my brake->throttle transitions, reducing or eliminating the delay in the middle that lets the suspension unload a bit, while keeping that initial throttle application very fine and light. I may start playing with left-foot-brake stuff on the street a bit in the next month or two and see if I can get used to that (and if that goes well, may try a little trail braking with that foot as well).
Last session of the weekend I had some fun with a 350z guy I see at the track a lot (apparently he lurks here, hi Tim!), we got into a good groove out of the rest of traffic and swapped back and forth a bit chasing each other down. I let the fun get the better of me and had a multiple near-spin events going a bit too hot and deep into a corners and/or getting a little too gas-happy on the way out. I'm sure the instructor was rolling his eyes at me for regressing, but eh, it was a ton of fun and it let me exercise some car control and recovery / off-line skills, so it was all good. No actual spins or off-track excursions all weekend, so that's always awesome.